SC/NATS1560 UNDERSTANDING

FOOD

INTRODUCTION TO THE COURSE

Course Director: Daniela Monaldi, dmonaldi@yorku.ca
Online tutorials: Thursdays 14:30-16:00 (end time is approximate)
Online office hours: by appointment
YORK UNIVERSITY LAND ACKNOWLEDGMENT
We recognize that many Indigenous nations have longstanding
relationships with the territories upon which York University campuses
are located that precede the establishment of York University. York
University acknowledges its presence on the traditional territory of
many Indigenous Nations. The area known as Tkaronto has been care
taken by the Anishinabek Nation, the Haudenosaunee Confederacy, the
Huron-Wendat, and the Métis. It is now home to many Indigenous
Peoples. We acknowledge the current treaty holders, the Mississaugas
of the Credit First Nation. This territory is subject of the Dish with One
Spoon Wampum Belt Covenant, an agreement to peaceably share and
care for the Great Lakes region.*

https://ireworkshop.laps.yorku.ca/land-acknowledgement/
Hello from Curious George!
 COURSE CONTENT
• This course is an introductory exploration of the nature of food and food
systems from an interdisciplinary point of view.
• We review the basics of nutrition according to current nutrition science.
• We also survey the technology of food production, preservation, and
processing, putting it in historical perspective and peering into the future.
• We consider the social, economic, and environmental implications of
industrial agriculture and the food industry.
• Finally, we examine several major controversies
that center upon food.
• You are expected to be able to perform basic
arithmetic (addition, subtraction, multiplication,
and division) and to calculate percentages.
• No prior background in science is assumed. All
that you need is passion for food, a curious mind,
and willingness to learn some fundamental
scientific concepts.
 COURSE STRUCTURE
• The course runs in the Winter 2021 term, 11 January – 12 April
• It is delivered completely in remote on the eClass platform
• It consists of required readings and viewings, slide presentations,
activities, assignments, and tests
• All the components are essential to your success
• It is structured into 12 weekly units, with one topic presented every
week
• You can follow the course synchronously or asynchronously, as long as
you respect the deadlines
• Weekly topics, required readings, and assessment deadlines are
detailed in the Course Schedule
 COURSE TOPICS
1. Introduction to the Course; 5. Food Gone Bad
Science and Technology meet
6. Preserving and Preparing Food
Food; and Food and the Atomic
Theory of Matter 7. Food and Fermentation
2. The Macronutrients Part 1: 8. Where Food Comes From
Energy and the Carbohydrates 9. Industrialization of Food
3. The Macronutrients Part 2: The 10.Genetics and Food
Proteins and the Lipids 11.Food in Society
4. The Micronutrients; Food in the 12.The Enlightened Eater
Body
 GRADING SCHEME
• The Course Total is the sum of
oActivities 1-10 10%, every week except weeks 11 and 12
oTest 1 15%, due 28 Feb at 11:59 pm
oTest 2 15%, due 11 Apr at 11:59 pm
oAssignment 1 20%, due 7 Feb at 11:59 pm
oAssignment 2 20%, due 7 Mar at 11:59 pm
oAssignment 3 20%, due 28 Mar at 11:59 pm
• The final grade is a letter grade based on the Course Total according to
the York University Grading Scale
• Read carefully and completely the information and instructions for the
assessments in the respective sections of the course website
 TEXTBOOK AND OTHER REQUIRED MATERIAL
• Course Outline, posted in the course website. It contains all the practical
information that you need for the course.
• Course Schedule, posted in the course website. It contains all the
information about dates, topics, readings, and assignments.
• Textbook: Richard Jarrell, SC/NATS 1560 3.00 Understanding Food (Course
Kit, 2012-2021). Available at the York University Bookstore
‒ We will be using the latest edition of this textbook, dated 2017-2020. You
may also use any older editions, as long as you are aware that some
corrections and updates have been made. A file listing the corrections
and updates is provided in the course website.
‒ This year, the textbook includes an Addendum, titled “Errata and
Addendum January 2021”. A print copy of the Addendum is included in
the new copies of the textbook. A digital copy is posted in the course
website.
• Other material (articles and videos) required for the Assignments, as
detailed in the Course Schedule. Posted in the course website.
 COURSE COMMUNICATION AND POLICIES
• Read the Course Outline completely, including the Course Policies
section
• Lecture slides, lecture recordings, tutorial recordings, assignments
and supporting material are posted in the course website
• All class-wide announcements are made through the Course
Announcements forum
– emailed to your class-list email address and posted in the forum
• Be sure to read all the Course Announcements and visit the course
website regularly
 GETTING IN TOUCH
• You are welcome to get in touch with me any time you have a
question or need assistance on any aspect of the course
• You are welcome to ask questions during the tutorials or via
email, at dmonaldi@yorku.ca.
• Please, follow basic emailing etiquette (see next slides)
• Please, do not use the eClass messaging tool
• Please, do not try to contact the TAs

• If you require accommodations, contact me as soon as possible via email, and do

so before the deadline(s) of the assessment(s) for which you need the
accommodation
• Course policy on adversities (from the Course Outline): If an adverse factor, such as
a disability, a protracted illness, or some personal hardship, interferes with your
ability to participate in the course or to prepare for a test or assessment, contact
me as soon as possible to discuss possible accommodations. I will not take into
consideration adversities that will be notified to me only after a mark was
assigned.
EMAILING ETIQUETTE 1: HOW NOT TO EMAIL
nothing in the subject line
not from the York University
account, at risk of being rejected
by the spam filter
no opening salutation no proofreading

no self-identification and no information about the course

no closing salutation
and no signature
EMAILING ETIQUETTE 2: HOW TO EMAIL
pertinent subject line
sent from the York University
account, no risk of being
rejected by the spam filter
opening salutation
full name, student ID, and course

proofread to minimize spelling

and grammar mistakes
closing salutation
and signature
 ACADEMIC INTEGRITY AND COPYRIGHT
• Academic honesty and integrity are expected at all time
• Any suspected violation will be reported to the STS Department and
investigated, and charges will be laid if reasonable and probable
grounds exist
• Familiarize yourself with the Senate Policy on Academic Honesty and
Integrity
• Take the SPARK Tutorial on Academic Integrity and the Academic
Integrity Quiz in the course website
• Consult with me if you have any doubt
• All course content and assignments are covered by copyright and
cannot be reproduced or posted in any form
• Read the message from the Faculty of Science Dean’s Office regarding
Academic Honesty in the Course Outline (next slide)
 Message from the Faculty of Science Dean’s
Office Regarding Academic Honesty
• Numerous students in Faculty of Science courses, including NATS courses, have been
charged with academic misconduct when materials they uploaded to third party
repository sites (e.g. Course Hero, One Class, etc.) were taken and used by unknown
students in later offerings of the course. The Faculty’s Committee on Examinations and
Academic Standards (CEAS) found in these cases that the burden of proof in a charge of
aiding and abetting had been met, since the uploading students had been found in all
cases to be wilfully blind to the reasonable likelihood of supporting plagiarism in this
manner. Accordingly, to avoid this risk, students are urged not to upload their work to
these sites. Whenever a student submits work obtained through Course Hero or One
Class, the submitting student will be charged with plagiarism and the uploading student
will be charged with aiding and abetting.
• Note also that exams, tests, and other assignments are the copyrighted works of the
professor assigning them, whether copyright is overtly claimed or not (i.e. whether the ©
is used or not). Scanning these documents constitutes copying, which is a breach of
Canadian copyright law, and the breach is aggravated when scans are shared or uploaded
to third party repository sites.
SC/NATS1560 UNDERSTANDING FOOD

ASSESSMENTS AND GRADES

Course Director: Daniela Monaldi, dmonaldi@yorku.ca
Online tutorials: Thursdays 14:30-16:00 (end time is approximate)
Online office hours: by appointment
 ASSESSMENTS
AND
GRADES
• This presentations is about
o the assessments for NATS1560
Winter 2021
o the grades display in the Grades
table
• For the complete Grading Scheme of
the course, see the Course Outline
and the presentation, “Introduction to
the Course”
 ASSESSMENTS AND ACADEMIC HONESTY
• All the assessments in this course are individual. No collaboration is permitted
during the execution of the assessments.
• You must answer the questions by yourself, using only your knowledge and
understanding of the required course content and resources.
• Academic Honesty and Integrity are expected for all the assessments.
• By submitting any of the assessments, you are subscribing to the Academic
Honesty Agreement:
You agree that you understand York University’s Senate Policy on Academic Honesty
and will abide by this policy. You acknowledge that academic honesty requires you to
not cheat (attempt to gain an improper advantage), plagiarize, nor attempt or
actually alter, suppress, falsify or fabricate official academic record, application or
document. Suspected breaches of academic honesty will be investigated, and charges
shall be laid if reasonable and probable grounds exist and lead to the range of
penalties described in the guidelines of the policy. Note: Ignorance of this policy is not
an acceptable excuse for academic misconduct. For any question, please ask your
course instructor.
 ACTIVITIES
• Activities 1-10 are formative assessments. They are designed to activate your engagement,
promote active learning and self-assessment while you are studying the material of each
unit.
• Start each activity after completing the required readings and attending the presentations of
the corresponding unit. Read each question and the possible answers carefully before
selecting your answer. Use your knowledge and understanding of the course content to
select your answer. If you do not understand the question or are not sure about the answer,
return to the course material to obtain the necessary information.
• Do not use external sources of information. They are not needed, will confuse you, and will
waste your time. Submit your activity when you are confident that all the answers are correct
on the basis of the course material.
• The activities are time-limited. Once you start an activity, you have one hour to complete it. If
you run out of time, your incomplete attempt is submitted automatically.
• All your answers count toward your grade. Unanswered questions get a score of zero.
• One attempt only is permitted for each activity.
• You will know your grade for each activity right after submitting it. You will be allowed to
review your attempt after the deadline.
• Be mindful of the deadline (stated on the starting page of each activity and in the Course
Schedule). At the deadline, the activity will close, whether you completed your attempt or
not. Late submissions are not allowed for the activities.
 TESTS
• The tests are individual summative assessments. They are meant to test your knowledge and understanding
of the course content after you studied it. No collaboration and no aids are allowed during the tests.
• You must answer the questions by yourself, using only your knowledge of the course content.
• Each test consists of 30 multiple-choice questions and is worth 15% of the Course Total. Test 1 covers the
content of weeks 1-6, Test 2 weeks 7-12.
• When taking a test, turn off your cell phone, as you would do in a regular in-class test, and close all the apps
and all the browser tabs, except the one that you are using for the test. Close also all your books and
notebooks. You must respect the rules of academic integrity according to the Academic Integrity policy of
the York University Senate. Please, be warned that every suspected violation of academic integrity will be
prosecuted.
• Each test is open for a period of several days. Within the open period, you may take the test when you
decide. Check the opening date and the deadline carefully for each test.
• The tests are time-limited. Once you start the test, you have 30 minutes to complete it. Mark your answers
without skipping any question (the navigation is sequential, which means that it is not possible to return to
previous questions), and click on "Submit all and finish" when you are done answering all the questions. If
the time expires, the answers you marked will be submitted automatically.
• Be mindful of the deadline date and time. The test will close at the deadline. If you start the test less than 30
min from the deadline, you will have less than 30 min to complete it.
• One attempt only is permitted for each test may be taken only once.
• The questions are presented sequentially, one at a time, in the forward direction only. It is not possible to
navigate back to previous questions. To be completely clear, after you move from one question to the next,
you cannot return to the previous question even if you have not answered it.
• If you submitted a Letter of Accommodation that requires extra time for tests, the time limit of the test is
extended according to your accommodation. However, be sure to start the test sufficiently in advance of the
deadline. If you start the test too close to the deadline, you will not have the extra time available.
 ASSIGNMENTS
• Assignments 1-3 are formative and summative assessments. They are designed to activate your engagement,
promote active learning and self-assessment while you are studying the required material, and to test your
knowledge and understanding of the relevant content.
• Each Assignment is to be completed on the basis of the relevant course material and of the resources
required for each question. The resources required are specified in the Assignment file, and are posted or
linked the “Resources” section of the course website. Do not use external sources.
• Assignment 1 is closely related to Topics 1-4. Assignment 2 is closely related to topics 5-7. Assignment 3 is
closely related to Topics 8-9.
• You must write all your answers by yourself individually, in your own words, using the appropriate
terminology and concepts learned in the course in a precise and independent manner.
• Since the assignments are based exclusively on course material and specifically assigned resources,
referencing is not required.
• The assignments are composed of one or more parts, and each part is composed of one or more questions.
The worth of every question is indicated beside the question. Each of the assignments is worth 20% of your
Course Total.
• For each assignment, download the file corresponding to the assignment and answer the questions
following the instructions. Enter you answers in the corresponding Turnitin module.
• Submit your assignment no later than the deadline indicated in the Course Schedule.
• Late penalty: late assignments will be penalized at the rate of 1% of your Course Total per day, or
equivalently, 0.042% of your Course Total per hour. This means that an assignment that is 20 or more days
late will automatically get a grade of 0.
 HOW TO ACCESS THE GRADES TABLE

your
grades
GRADES your grades
0.85
ranges (special notes)

TABLE 1.00
(0.00)
0.75
0.65
0.90

73
14.6

11.5

Current standing
Course Total 30.25 41 30.25/41 = 73.78%
By for now!
 SCIENCE AND TECHNOLOGY
MEET FOOD

Image credit: Getty Images

SC/NATS1560 UNDERSTANDING FOOD SUMMER 2020

 LEARNING OBJECTIVES
• To define science and technology and explain
how they are related to food
• To describe the main general characteristics of
modern science
• To define nutrition science and food science &
technology
• To distinguish between foods and nutrients
• To give a preview of human nutritional needs

2
 UNDERSTANDING FOOD
• Today, to understand food we rely mostly on modern
science
• Our methods of food production and processing are
largely based on industrial technology
• Nutrition science: the scientific study of the processes
through which food provides nourishment to the body
• Food science, also known as food science and
technology: scientific and technological research on
the properties of food substances, aimed at inventing
new food products and new methods of preservation
and processing
• Other sciences, such as agricultural science and
environmental science, study the systems of food
production
3
 SCIENCE AND TECHNOLOGY
• Science: systematic study to obtain knowledge about
the natural world, and the knowledge so produced
• Technology: manipulation of nature for practical
purposes, and the artifacts and systems so produced
• In our culture, science and technology are so closely
interdependent that we often talk of “science and
technology” as an inseparable pair. In many cases we
can describe them as “technoscience”
• Technoscience has many significant consequences,
good and bad, intended and unintended
• Technoscientific controversies often arise, concerning
technical, social, political, and ethical issues
4
 SCIENCE AND TECHNOLOGY
MEET FOOD
• Nutrition science and food technoscience share the
general characteristics of the modern sciences
• General characteristics of the modern sciences
− materialism: a living organism is just a physical system
governed by the laws of matter and energy
− reductionism: complex phenomena are reducible to
the physical and chemical interactions of their
simplest components, atoms and molecules
− experimentalism: scientific explanations must be
derived from and supported by experiments
• Technoscientific controversies around food: entangled
technical, social, political, and ethical issues 5
 REVIEW
• Nutrition science and food science are reductionist
qTrue
qFalse
• What do we mean when we call
nutrition science “reductionist”?
• That it aims to explain the
complex phenomena of the body
and its relation to food by
reducing them to molecular
processes
6
 FOODS AND NUTRIENTS
• No human diet consists of a single kind of food
• Foods: substances that we eat; commonly recognizable parts
of a diet
• Nutrients: chemically identified components of foods that
have been found to provide nourishment
• The foods we commonly eat are complex sources of nutrients
• Almost none of the foods we
commonly eat is composed by a
single nutrient or by a single type of
nutrients
• Nutrition science aims to
“understand food” by identifying all
the nutrients needed for a healthy
diet, finding out in what quantities
they are needed, and clarifying
their functions
7
 HUMAN NUTRITIONAL NEEDS:
A PREVIEW
• Water
• Carbohydrates
− digestible Macronutrients, or
carbohydrates energy-giving
• Proteins
• Lipids nutrients
• Minerals Micronutrients
• Vitamins
• Dietary fibre (or
indigestible
carbohydrates)
• Phytochemicals
8
 REVIEW
• What is an example of food?
• What is an example of nutrient?
• What are the nutrients that our body can use for
energy?
• The macronutrients:
- carbohydrates,
- fats
- proteins

Pieter Claesz, Still life, 1630

9
 TO WRAP UP
“The list of nutrients that
are essential or otherwise
useful to human physiology
is long, is complicated by
conditions, restrictions, and
ambiguities, and is almost
certainly incomplete.”
Marion Nestle, Food Politics. How the Food Industry Influences
Nutrition and Health, 2013, p. 395.

Marion Nestle

10
GENETICS AND FOOD
Part 1

NATS 1560 UNDERSTANDING FOOD

 LEARNING OBJECTIVES
• To define plant and animal breeding, species,
breeds, hybrids, straight breeding and
crossbreeding
• To review a few examples of the uses of plant and
animal breeding in the history of agriculture
• To introduce the basics of classical genetics
• To discuss the Green Revolution and its
connections to plant breeding, genetics, and
industrial agriculture
DOMESTICATION AND SELECTIVE BREEDING
• About 14000-12000 years ago, Native Mexican farmers
selectively bred teosinte, a
humans began to domesticate wild grass, to produce corn.
plants and animals for agriculture
and other purposes
• Selective breeding or artificial
selection: controlled reproduction
to select desirable characteristics

• Today’s domesticated varieties are

Yes, we are the domesticated distant descendants of wild species
descendants of the grey wolf.
− modified for human purposes by
means of selective breeding
− often unable to survive without
human support
 SPECIES AND BREEDS
• Species: a category of organisms that normally
breed with one another
− different species of the same genus can
sometimes mate, different genera very rarely
• Breed: group of animals or plants with common
lineage within a species, especially one
developed by artificial selection and maintained
by controlled propagation
− other terms for breed: subspecies, cultivar
(plants), strain, variety, population, race
• Purebred: produced by the controlled
mating of an unmixed breed over
many generations
• Crossbred: produced by the mating of A zorse, a hydrid of a zebra and a horse
two different breeds of the same
species
• Hybrid: of mixed origins, crossbred or
produced by the mating of two
different species of the same genus Seedless watermelons
A purebred Arabian horse
are crossbreds
 REVIEW
• When did farmers begin to use selective
breeding or artificial selection?
• What is the difference between species and
breed?

• What is an example of
an intraspecific hybrid?
• What is an example of
an interspecific hybrid?
© Toby Bridson
 ANIMAL BREEDING
• Straight breeding: mating individuals of the same breed
− to achieve uniformity of characteristics
− problem of inbreeding depression: reduction of health, fertility,
and longevity
• Cross-breeding: mating individuals of different breeds
− to achieve complementarity of characteristics
− to produce heterosis, or hybrid vigour: increase of size, health,
fertility, and longevity
− but it can also be damaging to the health of offspring
• Post-WII reproductive technologies:
− from 1950s, artificial insemination, to increase breeding efficiency
− From 1980s, embryo transfer and in-vitro fertilization
 PLANT BREEDING
• Practiced since the
dawn of agriculture
− selection of cultivars
with wanted characters
− hybridization: cross-
pollination and grafting
• 1865, Gregor Mendel’s
experiments on
hybridization

Gregor Mendel
(1822-1884)
 REVIEW
• What are two
examples of post-WWII
reproductive
technologies? © Toby Bridson

• When Gregor Mendel hybridized two purebred

strains of pea plants, what did he find in the first and
in the second generation of hybrids?
• What did Mendel conclude from his experiments
about the mechanism of plant hybridization?
 CLASSICAL GENETICS
• Genetics = the experimental study of
biological inheritance to better
understand and control breeding
• Key idea of early genetics: specific
characters are transmitted from parents
to offspring as individual, independent
units
• Gene = unit of heredity
• Genotype = set of genes related to a
given character, or the full set of genes of
an individual
• Phenotype = actual character or set of The fruit fly (Drosophila) was the
characters of an individual model organism of classical genetics

• 1900s-1930s
− the carriers of genes are the chromosomes, microscopic
structures that appear in the cell nucleus during cell division
− genetic mutations are biochemical changes in the chromosomes
 APPLICATIONS OF
CLASSICAL GENETICS
• The birth and growth of the new science of
genetics was supported by
− interest in selective breeding of plants and
animals to improve agriculture
− interest in “good breeding” in human
populations to “improve” society,
Charles E. Saunders (1867-
− eugenics 1937) and Marquis wheat

CANadian • Classical genetics was used by plant

Oil Low Acid breeders and agronomists to enhance
traditional breeding methods
• Agricultural successes in Canada
− 1940s, rust-resistant variety of Marquis
wheat (Charles E. Saunders, 1906)
− canola (University of Manitoba, 1978)
 REVIEW

• What is the key idea of classical genetics?

• What are two examples

of agricultural
applications of classical
genetics in Canada?
 THE GREEN REVOLUTION
• Agricultural reforms in developing countries
in 1950s-1960s, aiming to implement
industrial agriculture techniques and
increase agricultural production
• Promoted, organized, and funded by
American foundations and international
agencies in collaboration with local Norman E. Borlaug (1912-2009),
governments From The Economist, 17-9-2009

• Led by Norman E. Borlaug and other

agronomists
• Higher productivity of selected
varieties of cereal grains (wheat,
maize, rice) and other crops (beans,
cassava, cotton)
• High technological input and other
issues attending industrial agriculture
Wheat yield in selected countries, 1950-2004
 REVIEW

• What was the Green

Revolution?

• What were the positive and negative

consequences of the Green Revolution?
GENETICS AND FOOD
Part 2

Source: Image gallery of the Human Genome Project

NATS 1560 UNDERSTANDING FOOD

 LEARNING OBJECTIVES
• To introduce the transition from classical genetics to molecular
biology, and the identification of strands of DNA with the genes
• To introduce the basics of the double-helix structure of DNA and its
relation to the genetic code
• To define genetic engineering, genetically modified organisms, and
the main kinds of genetic engineering: cloning, gene transfer, and
gene editing
• To review the state of animal cloning and it use for food
• To identify and discuss a few examples of GMO foods
• To discuss why GMOs are controversial and review the main points of
the arguments in favour and against the genetic engineering of foods
 FROM CLASSICAL GENETICS
TO MOLECULAR BIOLOGY
• 1940s, molecular biology:
− chromosomes are made of DNA
and proteins
− genes are segments of DNA
responsible for the synthesis of
specific proteins
• 1953, discovery of the structure of
DNA, the double helix
− DNA molecular structure is the
same for all living organisms
− different species are distinguished
by the specific sequence of genes
in their DNA (genome)
DNA STRUCTURE AND THE GENETIC CODE
• DNA is composed of two anti-parallel
strands of nucleotides
• nucleotide = a phosphate group, a five-
carbon sugar and one of four types of
nitrogen bases
• Complementary base pairs: adenine (A)
and thymine (T), guanine (G) and
cytosine (C)
The ladder of
Source: National Human Genome Research Institution,
nucleotides is at https://knowgenetics.org/nucleotides-and-bases/
twisted into a
double helix. • The sequence of bases is the “genetic code”, a
template used by the cell to construct all the
proteins specific to the organism
• Central dogma of molecular biology: “DNA
makes RNA makes proteins” (F. Crick, 1958)
• The knowledge of DNA structure made
genetic engineering possible
 REVIEW
• From the point of view of genetics, what distinguishes an
organism from another?

• What is the genetic code of an

organism, and how is it related
to DNA?

© Toby Bridson
 GENETIC ENGINEERING
• Since 1970s, genetic engineering (GE): direct manipulation
of DNA to transfer genes from one organism to another or
modify the genome of an organism
• GMO = a genetically engineered or genetically modified
organism
• Types of genetic engineering
−Cloning: transfer of the entire nuclear DNA of a donor
organism into an emptied-out egg cell of the same
species to produce a genetic copy of the donor
−Gene transfer (aka gene splicing or recombinant DNA
technology): transfer of a specific gene from the DNA of
a donor organism to the DNA of a target to reproduce
single genetic traits independently of the species of
donor and target
−Gene editing: modification of one or more genes in an
organism
 FOOD FROM CLONED ANIMALS?
• First cloned mammal, Dolly the sheep, by Ian Wilmut and his team,
University of Edinburgh, Scotland, 1996
• Cloning now possible for many animal species
− mice, cats, dogs, goats, pigs, horses, cattle, etc.
• Cloning factories in China and USA
• Animal cloning raises many ethical concerns, especially about the
welfare of the cloned animals
• 2007, FDA approval of marketing of food products from cloned
animals without labelling
− policy based on biotech industry claim of “substantial equivalence”
• Sept. 2015, EU banned the cloning of farm animals
• In Canada, food from cloned animals is subject to “novel food”
regulations and must be approved for sale
− no food products from cloned animals are currently approved for
sale in Canada
 GENE TRANSFER
• A wanted gene is identified in
the DNA of a donor organism
• the gene is cut out by means
of a restriction enzyme and is
implanted in the DNA of
another organism, producing
−recombinant DNA, or rDNA
−transgenic organism
• using a plasmid or a virus as a vector, electro- or
chemical poration, microinjections, or a “gene gun”
• to genetically engineer transgenic varieties of
bacteria, plants, or animals
 REVIEW
• What is the difference between gene transfer and cloning?
• What is a transgenic organism, and how is it different from a hybrid?
ENGINEERING BACTERIA THAT WILL WORK FOR US

• Specific genes are transfered

into bacteria to make the
bacteria produce proteins of
interest
• Early examples of successful
gene transfer: human genes
were transplanted into
bacteria to make them
produce
−insulin (r-insulin, 1978)
−human growth hormone
(rHGH)
ENGINEERING NEW PLANTS AND ANIMALS
• GE is also applied to make new
“designer” plants and animals
−gene transfer from a donor (e.g. a
bacterium) to a target plant or
animal
−silencing or editing one or more
genes in the target organism
• Examples of GE foods now on the market:
− Roundup-ready crops (soy,
corn, cotton, etc.)
− Bt crops (corn, rice, soy,
cotton)
− AquAdvantage salmon
− Arctic® Apples
 REVIEW
• What is an early example of gene splicing?
• What are some examples of GMO foods currently on the market?
 THE GMO CONTROVERSY
FOR GMOs AGAINST GMOs
• GE is not qualitatively different • GE is qualitatively different from
from traditional breeding traditional breeding methods
methods • Gene interactions and expression
• Just more controlled, accurate, of genes in different cellular
and efficient than traditional contexts are still poorly
breeding understood
• More environmentally friendly • High-input GE crops, genetic
than conventional agriculture contamination of wildlife,
• Patenting of GE organisms is reduction of biodiversity, super
needed to protect intellectual weeds, superbugs
property and foster innovation • Patenting restricts access to seeds
• The public is ignorant and and to information, and is one
misinformed, and reacts more cause of socio-economic
emotionally out of unjustified inequalities
fears • Lack of transparency and public
scrutiny is undemocratic
 REVIEW
• What are the arguments of the proponents and of the opponents of
GMO foods?
 FOOD IN SOCIETY

Richard Adams, “The Countryside Banquet”

First part
NATS1560 UNDERSTANDING FOOD
 OVERVIEW
• Food governance
• Food trade and the globalization of food
• Food as a public health issue: food security
and food safety
• Sustainability and climate change
 THE POLITICAL DIMENSION OF FOOD
• Politics shapes the food choices of individuals in
numerous ways, for example through
– land property and labour legislation
– agricultural policy: tax breaks, subsidies, price controls
– infrastructure: irrigation, transports, power
– trade policy, domestic and import/export
– food and public health policy
– food safety regulations and enforcement
– food security policy, national and global
– scientific research and technological innovation
– environmental policy
 FOOD GOVERNANCE
• Food production and
processing is one of
the main sectors of
the economy

• Food security, food

safety, and nutrition are
also public health
matters
 TEST PRACTICE
1. Politics shapes the 2. What Canadian
food system by government
(choose the best department is tasked
answer) with food governance?
a. all the answers a. Health Canada
b. providing b. Statistics Canada
infrastructure c. Canada Council for the
c. supporting scientific Arts
research d. Department of
d. regulating trade National Defence
 FOOD TRADE
• Every country aims to assist its farmers and food
manufacturers by promoting the export of their
products while protecting them from competition by
limiting the import of goods from abroad
• Trade barriers: tariffs, import bans and quotas,
subsidies and assistance policies
• Protectionist policies have been applied by all industrial
countries to foster their own growing industry and
become global economic powers
• Since WWII, industrial countries have launched a
concerted effort to increase international trade by
removing trade barriers: international free-trade
• Until 1995, agriculture and food industry were largely
exempted, the food supply being regarded as a matter
of national security
 THE GLOBALIZATION OF FOOD
• 1947, General Agreement on Tariffs and Trade
(GATT), 20 countries
– food treated as an exception
• 1995, World Trade Organization (WTO), at
present 164 countries
– food is a business as any other
– need for international food safety standards
• Free-trade zones, e.g.
– 1993 European Union (EU), 27 countries, 500 million
people, 30% of world’s economy
– 1992 North American Free Trade Agreement (NAFTA),
USA, Canada, Mexico, almost 500 million people
 NEW FREE-TRADE ZONES
Canada-United
States-Mexico
Agreement
(CUSMA), or “New
NAFTA”, Nov. 2018
Comprehensive Economic and
Trade Agreement (CETA), Canada-
EU, signed in 2013 Trump withdrew the USA from the TPP.
Now it is the Comprehensive and
Progressive Trans-Pacific Partnership.

Transatlantic Trade and

Trans-Pacific Partnership (TPP), 12 Pacific-Rim Investment Partnership (TTIP),
countries, signed in 2016. Now, CPTTP. USA-EU, under negotiation
 TEST PRACTICE
3. What is the aim of 4. What is an example of
free-trade a trade barrier?
agreements? (Choose the best
a. To eliminate trade barriers answer)
b. To support domestic small- a. A tariff
scale producers b. An import quota
c. To improve and strengthen c. A subsidy
food safety standards d. All the answers
d. To enhance international
environmental protection
regulations
 FOOD SECURITY:
THE RIGHT TO BE FREE FROM HUNGER
 FOOD SECURITY IN THE WORLD
• Today, around 821 million people, 1 in 9 people, face
food insecurity
• Africa has the highest prevalence, 1 in 5 people

• Hunger is also on
the rise in Western
Asia
• Root causes are
poverty, war, and
climate change
 FOOD INSECURITY IN CANADA

• 8.7% of household were food insecure in 2017-

2018 in Canada
• 22.6 % for single parents with children
• 36.7% in Nunavut
 TEST PRACTICE
5. For the United Nations, 6. What part of Canada
food security is suffers from food
a. another term for food insecurity the most?
safety a. Prince Edward Island
b. an unrealistic goal b. Yukon
c. the responsibility of c. Nunavut
individual families d. Northwest Territories
d. a human right
FOOD IN SOCIETY

Richard Adams, “The Countryside Banquet”

Second part
NATS1560 UNDERSTANDING FOOD
 FOOD AND HUMAN HEALTH
• 1940s, USDA Basic Seven
• 1992, Food Pyramid
• 2005, MyPyramid
• 2011, MyPlate

• 1942, Canada’s Food Rules

• 1961, Canada’s Food Guide
• 1992, Revised Food Guide
• 2007, Updated Food Guide
2019 CANADA’S FOOD GUIDE
 TEST PRACTICE
7. What foods did the USDA 8. How is the 2019 Canada’s
Food Pyramid recommend Food Guide different from
to eat in the largest other food guides?
amounts? a. It was written by a
a. Non-processed foods committee of nutrition
b. Fruit and vegetables experts
c. Meat, fish, and dairy b. The process of writing it
d. Bread, pasta, and cereals included consultations
with the food industry
c. It recommends to limit the
consumption of highly
processed foods
d. It uses simple words and
colorful graphics
 FOOD SAFETY
• Food safety: prevention of food-borne illness
• 1985, Canadian Food and Drug Act
– illegal to sell tainted food, mislabel and adulterate it,
store it in unsanitary conditions
– regulations for import and export of food
• 1997, Canadian Food Inspection Agency (CFIA)
• 1998, Canadian Food Inspection System
– producers have primary responsibility for quality
– consumers have right to know what they are buying
• CFIA responsibilities further defined by the Fish Inspection
Act, the Meat Inspection Act, the Canada Agricultural Products
Act, and the Consumer Packaging and Labelling Act
• 2012, all food-safety laws consolidation under the Safe Food for
Canadians
– strengthened protections against deception and tampering
– improved food traceability
– enhanced import controls and export certifications
 FOOD AND SUSTAINABILITY
• Until now, economic development
has prioritized quantity over
quality and disregarded the harm
made to human health and the
environment
- deforestation and destruction of
ecosystems
- loss of biodiversity
- loss of fertile soil
The second goal of
- water and air pollution the UN 2030 Agenda for Sustainable
- climate change Development is to end hunger and promote
sustainable agriculture!

• Sustainability is the ability to meet the needs of the present

without compromising the ability of future generations to meet
their needs
• We now know that the present food system is unsustainable
• A profound change to the global food system is needed
 TEST PRACTICE
9. What is sustainability? 10.The present food system is
a. The ability to produce a. sustainable
enough food for the b. unsustainable
growing population c. the best we can expect to
b. The ability to meet have
present needs without d. able to meet human needs
compromising the ability now and in the future
of future generations to
meet their needs
c. The capacity for economic
growth
d. The right to have sufficient
and nutritious food
 THE GREENHOUSE EFFECT
AND THE CLIMATE
• Natural
greenhouse effect
• Without natural
greenhouse effect
the temperature
of the earth
would be -17 ᵒC

• Since the Industrial Revolution, human activities

have artificially increased the greenhouse effect,
causing climate change
 GREENHOUSE GASES
• Greenhouse gases (GHG), THE CARBON CYCLE
aka radiatively active gases
(RAGs): atmospheric
− water vapour (H2O) compartment
− carbon dioxide (CO2)
terrestrial
− methane (CH4) compartment
− nitrous oxide (N2O)
− Since 1930s, also human- oceanic
geological compartment
made CFCs and other compartment
fluorinated gases earthobservatory.nasa.gov/features/CarbonCycle

• The carbon cycle and the burning of fossil fuels

• Methane from livestock farming and natural gas lines
• Nitrous oxide from synthetic fertilizers and fossil fuel
combustion
• CFC and other fluorinated gases, POPs
 IMPACT OF CLIMATE CHANGE
• Melting of glaciers, raising sea levels, flooding of
coastal areas
• Changing weather patterns with increase of extreme
weather events, hurricanes, blizzards, droughts, heat
waves, wildfires
• Longer frost-free and growing seasons in Canadian
agriculture
• Higher risks of pests and diseases
• Higher risk of soil erosion
• Needs to drastically reduce
GHG emissions
• Need to switch to
sustainable food
production and processing
 TEST PRACTICE
11. Which of the following is a 12. How does human activity
greenhouse gas? (Choose change the carbon cycle?
the best answer) a. Moving carbon from the
a. Water vapour geological to the
b. Methane atmospheric compartment
c. All the answers b. Increasing the absorption
d. Nitrous oxide of carbon in the oceanic
compartment
c. Favoring the storage of
carbon in the geological
compartment
d. Human activities do not
change the carbon cycle
THE ENLIGHTENED EATER

Giuseppe Arcimboldo,
Vertumnus, 1591

PART 1
NATS 1560 UNDERSTANDING FOOD
 LEARNING OBJECTIVES
• To review the food labelling requirements in
Canada
• To distinguish between labelling requirements
and manufacturer’s claims
• To describe organic farming, outline its
original goals, and discuss its
institutionalization
• To define the organic standards in Canada
 FOOD LABELLING
• Food labels in Canada are regulated by
− the Food and Drug Regulations (under the Food and Drugs Act)
− the Safe Food for Canadian Regulations (under the newer Safe
Food for Canadians Act as well as other acts relevant to food
safety and food import-export)
• These laws
− prohibit deceptive labelling
− prescribe labelling requirements
– net quantity of product
– identity and main place of origin
– for some foods, packaging date, “best before” date,
storage instructions
– ingredients and allergens
– nutrition facts
• The Canadian Food Inspection Agency and
Health Canada are responsible for defining and
enforcing food labelling regulations
 FOOD LABELLING CHANGES
• Dec. 2016, changes to the list of ingredients and
Nutrition Facts table on packaged foods
• Part of the Healthy Eating initiative, which also
includes
− the new Canada Food Guide
− the elimination of artificial trans fat
− restrictions on marketing to children
− improving access to fresh food for Northern
isolated communities
• Food industry has until 2021 to comply
 LIST OF INGREDIENTS
• Ingredients must be listed by their common names in
descending order by weight
– except spices, seasoning (other than salt), herbs, natural and
artificial flavours and flavouring agents, food additives, vitamins,
and minerals, which can be listed at the end without order
• 2016 changes to make it easier to find, read, and
understand the list of ingredients:
THE OLD NUTRITION FACTS TABLE
THE NEW NUTRITION FACTS TABLE
 MANUFACTURER’S CLAIMS
• Nutrient content claims • Diet-related health
claims

These claims
are made for
marketing As a rule of thumb,
purposes the more health
claims are on the
front label, the less
healthy the food is
 REVIEW
• What is the difference between labelling
requirements and manufacturer’s claims?
• What agencies are responsible for defining and
enforcing food labelling regulations in Canada?
• What information must be
present on food labels in
Canada?
• What information must the
nutrition facts table contain?
 ORGANIC FOODS
• Organic farming started in 1960s as a
grassroots movement that opposed the
industrialization of agriculture
• Grown together with environmentalism
and social justice concerns Dufferin Grove Organic
Farmers Market, Toronto
• for biological complexity and community
values
• Now, organic foods are the fastest
growing sector of food industry
• Largely coopted by agribusiness
• Institutionalized: national regulation
and standards
• But large-scale production and
distribution contradict the original
principles of organic farming
• Institutional standards can only
regulate a limited set of practices
 ORGANIC FOOD STANDARDS
• Since 2009, Canadian Organic Product Regulations
– organic content requires certification by CFIA recognized bodies
– only products with at least 95% certified organic content may be
labelled as "organic" or bear the "organic" logo
– products with 70-95% certified organic content may have the
declaration: "contains xx% organic ingredients"
– products with less than 70 per cent "organic" content may only
contain organic claims in the product's ingredient list
• Canadian Organic Standards
– plants grown without pesticides, artificial fertilizers, sewage sludge
– animals grown without antibiotics and hormones, fed organic feed,
no animal byproducts, having access to outdoors
– processed and packaged without synthetic additives and
preservatives
– not irradiated
– no GMOs and cloned organisms
 REVIEW
• What are the original goals of organic farming?

• Why were official

organic food standards
defined?
• What are the organic
food standards in
Canada?
THE ENLIGHTENED EATER

Giuseppe Arcimboldo,
Spring Woman, 1591

PART 2
NATS 1560 UNDERSTANDING FOOD
 LEARNING OBJECTIVES
• To discuss the value and limitations of nutrition science
• To distinguish the various types of scientific studies
used in nutrition research, and discuss their advantages
and disadvantages
• To identify some examples of controversial nutrition
claims
• To define two overweight parameters, BMI and waist
size
• To discuss the question of the raising numbers of
overweight and obese people in the contemporary
world
• To conclude the course with a few simple guidelines to
be an “enlightened eater”
 SCIENCE AND NUTRITION
• Scientific knowledge is trustworthy because it
derives from systematic, peer-reviewed research
• Scientists are trained professionals who support
hypotheses with evidence in a systematic way
• Peer review: the results of scientific research
undergo a process of scrutiny and evaluation by
independent competent scientists before being
published
• Human nutrition studies are difficult to carry out
and interpret
• Nutrition science is complex, young, evolving
• Types of nutrition studies: observational studies,
intervention studies, and metastudies
 OBSERVATIONAL STUDIES
• Observational studies: observation only, no
intervention
• Epidemiological studies: observations of populations
• Case studies: past histories of individual subjects are
examined
• Cohort studies: a group of subjects (“cohort”) is
monitored over a time period
• Longitudinal, prospective and/or retrospective
• Statistical correlations are possible indicators of cause-
effect relations
• Sources of errors: sample size, duration of study,
sampling bias, unreliability of self-reporting,
experimenter bias
 INTERVENTION STUDIES
• Intervention studies: intervention and observation
− independent variable: possible cause of a health outcome
− actions are taken to isolate the effects of the independent
variable to test a cause-effect hypothesis
− subject group and control group
− sources of error: sampling bias, subject bias (placebo
effect), experimenter bias
• Randomized controlled trials: random selection of
subjects and control group
− source of error: experimenter bias
• Double-blind randomized controlled trials, the “golden
standard” of intervention studies
 REVIEW
• What are the value and limitations of scientific
research in nutrition?
• What is the difference between observational
studies and intervention studies?

• What are the different types of

observational and intervention
studies?
• What are the possible sources of
error in observational and
intervention studies?
 METASTUDIES
• A metastudy is a statistical
analysis of data drawn from
several previous studies on
the same matter

• Sources of errors: quantity and

quality of studies examined,
variations of experimental
design, complexity of analysis
CONTROVERSIAL NUTRITION CLAIMS
• Fad-diet claims: “Fat makes you fat”, “Low fat diet is healthy”,
“Carbohydrates make you fat”
• The Lipid Hypothesis:

low density
lipoproteins hardening and
dietary cardiovascular
(LDP, “bad narrowing of
saturated fats disease
cholesterol”) arteries
in your blood

• Glycemic Index (GI) = speed of absorption of

carbohydrates, rise of glucose in bloodstream
− GI of glucose = 100
− GI of potatoes, white rice > 90
− GI of banana =53
− GI of pasta = 41
• Glycemic load = grams of carbs x GI/100
 OVERWEIGHT PARAMETERS
• Body Mass Index (BMI) =
body mass in Kg/(height in
m)2
− Healthy range, 18.5< BMI
< 24.9
− Obesity, BMI >29.9
− BMI is a statistical
measure only, not a
parameter of health risk
applicable to individuals
− BMI biases: muscle mass denser than fat, different correlation
with body fat for short vs. tall people, not valid for younger and
older people, pregnant or breastfeeding women
• Waist size as index of risk:
− increased risk, > 94 cm for men, > 80 cm for women
− substantially increased risk > 102 cm for men, > 88 cm for women
 REVIEW

• What are some examples of nutrition claims?

• What is the body mass

index, and what are its
problems when applied
to individuals?
 WHY ARE PEOPLE OBESE?
• The “eat more” environment: constant ready-
to-eat products availability, advertising,
portion distortion, supersizing
• Industrial food production and processing
• Adulterations and environmental toxins
• Sedentary lifestyle
• Stress
• Other?
WHAT IS AN ENLIGHTENED EATER?
• “Eat food. Not too much. Mostly vegetables”
(Michael Pollan)
• Shop around the perimeter of the supermarket
(Marion Nestle)
• The Okinawan rule: Hara Hachi Bu (“Belly 80%
full”)
• Prefer fresh local food in season
• Read labels
• Prefer foods that are not advertised
• Enjoy preparing and eating food with friends and
family (by yourself too—why not?)
GOODBYE!
 FOOD AND
THE ATOMIC THEORY OF MATTER

SC/NATS1560 UNDERSTANDING FOOD SUMMER 2020

 LEARNING OBJECTIVES
• To define atoms, molecules, elements,
compounds, and mixtures
• To explain the basics of chemical formulas and
chemical reactions
• To define catalysts and isomers
• To define organic chemistry, functional groups,
monomers, polymers, and macromolecules
• To explain the basics of states of matter and
phase changes
2
 KINDS OF MATERIAL SUBSTANCES
• Mixture: most material substances are
mixtures that can be separated and
purified into simpler substances by
physical means
• Pure substance: substance that cannot
be further refined without losing its
physical and chemical properties
− molecule: smallest particle of a pure substance

oxygen
− Compound: pure substance that can be
hydrogen
decomposed into other pure substances
by chemical means
− Element (or simple substance): pure
water substance that cannot be decomposed
into other substances by chemical
Electrolysis of water.
© Science Photo Library
means
3
THE CHEMICAL ELEMENTS

4
 ATOMS AND MOLECULES
• Atomic theory: all material substances hydrogen
atom

are constituted of atoms

• Atoms bind to form molecules oxygen
atom

hydrogen gas
molecule
oxygen gas
• Element: substance composed
water
molecule only of atoms of the same
molecule species
water • Compound: substance
composed only of identical
molecules, each molecule
composed of different atoms
5
 REVIEW
• What is the difference between
an element and a compound?
− An element is composed of
atoms of the same species, a
compound of atoms of different
species
Adapted from © Toby Bridson

• What is the difference

between a pure substance
and a mixture?
− A pure substance is composed
of molecules of the same
kind, a mixture of molecules
of different kinds
Adapted from © Toby Bridson
6
FOOD AND ATOMIC THEORY
Part 2

SC/NATS1560 UNDERSTANDING FOOD SUMMER 2020

 CHEMICAL FORMULAS
• Chemical formula: O2 oxygen gas

symbolic expression
representing the N2 nitrogen gas
chemical composition of
a molecule, i.e. the
species and numbers of H2 O water

atoms composing it
− chemical symbols for the NaCl table salt
elements
− subscript numbers for
the number of atoms of C6H12O6 glucose
each element
C12H22O11 sucrose
2
 CHEMICAL REACTIONS
• Chemical reaction: re-arrangement of the atoms
of the reactants into new molecules (products)
• Chemical equations, e.g.
reactants products
HCl + NaOH → NaCl + H2O
hydrochloric acid sodium hydroxyde sodium chloride water
(neutralization reaction, acid+base = salt+water)

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O

glucose oxygen carbon dioxide water
(oxidation reaction)
• A catalyst is a substance that facilitates the
reaction but is not changed by the reaction
3
 MOLECULAR STRUCTURE
• Molecular structure: arrangement
of atoms in a molecule in 3d space
• Structural formulas: 2d
representations of molecular
structure
• Isomers: molecules having the
same chemical composition but
different structures
– iso = equal
– mer(o) = part
• e.g. isomers of hexose, C6H12O6
4
 ORGANIC CHEMISTRY
• Organic chemistry: chemistry of carbon
compounds
− carbon compounds are characteristic of
living matter
− but also synthetic materials, e.g. many
kinds of plastics
• Organic matter is not different from
inorganic matter for its chemical Photo credit: unknown

composition but by the level of molecular

complexity
• Carbon is fundamental to life
because it can form the backbone of
large and complex molecules:
macromolecules
− macro: prefix meaning “large”
• Main elements in macromolecules:
C, H, O, N.
From economist.com

5
 MACROMOLECULES
• Functional groups: recurring
groups of atoms that determine
the reactivity of organic molecules, hydroxyl group

e.g.
− hydroxyl group, -OH (alcohols)
carbonyl group
− carbonyl group, -CO (aldehydes and
ketones) carboxyl group

− carboxyl group, -COOH (carboxylic acids)

− amino group, NH2 (amines)
amino group glycine glutamic acid

• Many macromolecules are

polymers, chains of monomers

Different representations of the structure of a protein

6
THE MACROMOLECULES OF LIFE

• What are the “macromolecules of life”?

© Toby Bridson

• Carbohydrates
• Lipids
• Proteins
• DNA

7
 STATES OF MATTER
condensed
water droplets • The same substance can
exist in different states of
steam or water vapour
matter, or phases
Water in solid, liquid, and gas state.
• Solid state: the molecules
are tied to one another in
a crystalline structure
• Liquid state: the molecules are loosely linked
• Gas state: the molecules are free to move
• Phase change: transition between states
• The melting point and boiling point are © Toby Bridson

specific to each substance

8
THE MACRONUTRIENTS

Bartolome Esteban Murillo,

The Pie Eaters, c. 1820

Part 1
FOOD AND ENERGY
NATS1560 UNDERSTANDING FOOD
 LEARNING OBJECTIVES
• To explain the equivalence between energy and heat,
and the primary function of food as “fuel” for the body
• To define the measurement units of food energy, the
kilocalories, and their moniker, “calories”
• To explain the difference between the gross energy and
the metabolizable energy of food
• To define the standard metabolizable energy values of
the macronutrients
• To apply the “4-9-4” rule to calculate the metabolizable
energy of a food
• To define and use the Acceptable Macronutrient
Distribution Ranges
2
 WHY DO WE NEED FOOD?
• Our body needs food for
− molecules, needed for the
growth and repair of
organs and tissues
− energy, needed for all
physiological processes From the NBC show, Parks and Recreation

• Energy exists in different forms, e.g., heat (thermal energy),

motion (kinetic energy), potential energy of chemical
bonds (chemical energy), etc.
• The body stores unused food energy as chemical energy in
fat molecules
• The body uses fat molecules for energy when food is
insufficient 3
 KILOCALORIES AND “CALORIES”
• Energy for body’s use is liberated when
molecules from food are oxidized inside body
cells
− a process similar to burning fuel to produce
kilocalories heat
• In nutrition, food energy is commonly
measured in units of heat: kilocalories (kcal or
Cal)
− familiarly but inaccurately called “calories”
• kilocalorie = amount of energy required
to raise the temperature of 1 kg of water
1°C at standard atmospheric pressure
– kilo = 1000
– calorie = energy required to raise the
temperature of 1 g of water 1°C at
standard atmospheric pressure

4
kilocalories

5
 HOW MUCH ENERGY
DOES FOOD PROVIDE TO OUR BODY?
• The only food molecules from which our body can extract
energy are those of the macronutrients:
− carbohydrates, fats, proteins
• Energy from food = energy from carbohydrates + energy from
fats + energy from proteins
• Metabolizable energy of a food = energy in the food – energy
losses due to incomplete digestion and excretion
• Standard values of metabolizable
energy:
- from carbs = 4 kcal/g
- from fats = 9 kcal/g
- from proteins = 4 kcal/g
- from alcohol = 7 kcal/g
- from anything else = 0 kcal/g
6
 STANDARD ENERGY VALUES:
THE 4-9-4 RULE
• To estimate how much energy food provides to the
body using the standard energy values:
- Metabolizable energy from carbs (kcal) = grams of
carbs x 4 kcal/g
- Metabolizable energy from fats (kcal) = grams of fats x
9 kcal/g
- Metabolizable energy from proteins (kcal) = grams of
proteins x 4 kcal/g
- Metabolizable energy from food = metabolizable
energy from carbohydrates + metabolizable energy
from fats + metabolizable energy from proteins
7
 HOW MANY CALORIES IN A FOOD?
USING THE STANDARD VALUES
• One 12 g chocolate chip cookie
contains
- 8 g of carbohydrates
- 1 g of proteins
- 3 g of fats
Andy Dwyer will have to
run at 11 mph for almost 3
• Metabolizable energy from min to burn that cookie!
the cookie:
• 8 x 4 = 32 kcal from carbs
• 3 x 9 = 27 kcal from fats
• 1 x 4 = 4 kcal from proteins
• Total = 32 + 27 + 4 = 63 kcal
8
 REVIEW
• What are the energy-giving nutrients?
• Approximately and in average, how much
metabolizable energy is provided by each of the
energy-giving nutrients?

• How much energy do the other

nutrients (non-energy-giving
nutrients) provide?
• What is the “4-9-4 rule”?

9
 HOW ACCURATE ARE
THE STANDARD ENERGY VALUES?
• Carbs, proteins, and fats from different foods have different metabolizable
energy content
• The standard energy values are averages calculated by estimating from
many measurements the average digestibility of macronutrients in an
average diet
• Originally estimated by American scientist, Wilbur O. Atwater around 1900
for an average diet of his time in the USA
• Modified Atwater Values, from kcalories
newer experiments (USDA
1955 and 1973) with a variety
of diets have yielded
- averages that differ little
(typically no more than 5%)
from Atwater’s standard values
- but non-negligible differences
between different foods

10
HOW MANY CALORIES IN A BANANA?
• One 100 g banana:
- 23 g carbs
- 1.1 g proteins
- 0.3 g fats
• With the standard values:
− 23 x 4 + 1.1 x 4 + 0.3 x 9 = 99.1 kcal
• With the Modified Atwater Values
− 23 x 3.6 + 1.1 x 3.36 + 0.3 x 8.37 = 89 kcal
− 10.1 kcal (11%) less
• The USDA National Nutrient Database and many food
labels today use the modified Atwater values
11
MACRONUTRIENT DISTRIBUTION

• Carbohydrates are the body’s primary energy source.

A healthy diet provides at least 45% energy from carbs
• In a healthy diet for adults, 20-35% of the energy
comes from fat and 10-35% from proteins
12
 MACRONUTRIENT DISTRIBUTIONS
(USING THE STANDARD VALUES)
• One 12 g chocolate chip cookie
− energy = 8 x 4 + 1 x 4 + 3 x 9 = 63 kcal
− 32 kcal/63 kcal = 51% from carbs
− 27 kcal/63 kcal = 43% from fats
− 4 kcal/63 kcal = 6% from proteins
• One chocolate chip cookie and one 100 g banana:
− (8 + 23) g x 4 kcal/g = 124 kcal from carbs
− (1 + 1.1) g x 4 kcal/g = 8.4 kcal from proteins
− (3+ 0.3) g x 9 kcal/g = 29.7 kcal from fats
− Total energy = 124 + 8.4 + 29.7 = 162.1 kcal
− 76.5% from carbs, 5.2% from proteins, 18.3% from fats
13
 REVIEW
• Does a diet of chocolate-chip cookies and
bananas provide an acceptable distribution
of macronutrients?
• Is a diet that provides less than 20% of
calories from fat associated with reduced risk
of chronic diseases?
• Is a diet that provides less than 45% calories
from carbohydrates associated with reduced
risk of chronic diseases?
• Given that the amounts of carbs, proteins,
and fats in coffee can be regarded as
negligible, how much energy do you get
from a cup of coffee?
• What percentage of calories in your diet
© Toby Bridson
should come from vitamins and minerals?
14
THE MACRONUTRIENTS

Johannes Vermeer,
The Milkmaid, c.1660

Part 2
CARBOHYDRATES
NATS1560 UNDERSTANDING FOOD
 LEARNING OBJECTIVES
• To explain in simple terms what carbohydrates
are, of what elements they are composed, and
how plants make them
• To identify the main kinds of carbohydrates and
classify them by molecular composition and
nutritional functions
• To explain in simple terms the nutritional
functions of the main kinds of carbohydrates
• To identify some of the main food sources of
carbohydrates
2
 CARBOHYDRATES
• Are produced by plants
through photosynthesis sunlight carbon
• capture energy from the energy dioxide
sun in their molecular C2O
bonds oxygen O2
• make the energy available
for biological processes in glucose
plants and animals C6H12O6
• are the main source of
energy for the human water H2O
body
• are hydrocarbons (hydrates of carbon) with oxygen
− general formula C n(H2O)m
3
 MAIN KINDS OF CARBOHYDRATES
• Carbohydrates differ in their molecular composition and in
their functions in human nutrition
• Nutritional classification: digestible, indigestible
• Molecular classification:
− simple carbs or sugars
− monosaccharides or simple
sugars
− disaccharides or double
sugars
− complex carbs
− oligosaccharides
− polysaccharides

4
 REVIEW
• What are the elements that
compose carbohydrates?
• What is the process by which
carbohydrates are made by plants?

• How are the main kinds

of carbohydrates
classified?

5
 SIMPLE CARBOHYDRATES OR SUGARS
• Monosaccharides (or single sugars): glucose,
fructose, galactose

glucose fructose galactose

• Disaccharides (or double sugars): sucrose, maltose,

lactose

sucrose maltose lactose

fructose—glucose glucose—glucose glucose—galactose
6
 COMPLEX CARBOHYDRATES:
OLIGO- AND POLYSACCHARIDES
• Chains of monosaccharides
• Indigestible carbohydrates or dietary fibre: plants’ structure
- Oligosaccharides (also in human milk and artificially produced)
- Indigestible polysaccharides (e.g., cellulose, inulin, psyllium)
• Digestible polysaccharides
- Starch (amylose and amylopectin): plants’ store of energy
- Glycogen: animals’ store of energy

7
 DIETARY FIBRE
• Oligosaccharides and indigestible polysaccharides
• Soluble fibre (e.g., pectin, gums, inulin, psyllium)
– slows down the absorption of sugar and the passage of chyme through
small intestine
– holds moisture and increases satiety
– some is digested (fermented) by human colon bacteria
• Insoluble fibre (e.g., cellulose)
– gives bulk and weight to feces
– speeds passage of feces through colon
• Whole plant foods contain both digestible carbohydrates and fibre
• Refined foods are foods from which fibre has been removed
• The standard energy value for carbohydrates, 4 kcal/g, represents
metabolizable energy. This means that, in theory, it does account,
on average, for the loss of energy due to the non-digestibility of the
fibre component in foods
8
 FOOD SOURCES OF CARBOHYDRATES
• Plants and milk
• Sources of sugars: milk, honey, fruits, vegetables,
sugar cane, sugar beet, malt, table sugar, syrups,
HFCS (aka “glucose-fructose” on Canadian labels)
• Sources of starch: grains, tubers, flour, bread,
pasta, pizza
• Sources of fibre: whole grains and whole-grain
products, vegetables, pulses, nuts, fruits, fibre
supplements and fibre-fortified food products
9
 REVIEW

• What are the dietary

functions of the
different kinds of
carbohydrates?

• What are some examples of food

sources of carbohydrates?
• What is a refined food?

10
THE MACRONUTRIENTS

Floris van Dyck, Still-Life with Fruit, Nuts and Cheese (1613)

Part 3: FATS
NATS1560 UNDERSTANDING FOOD
For class use only. Do not circulate.
 LEARNING OBJECTIVES
• To name the different kinds of lipids and identify
the kinds that are important for nutrition
• To explain the molecular composition of
triglycerides and distinguish the different types of
fatty acids
• To list the functions of fats in the body
• To list the main food sources of the different
kinds of fats, and explain the difference between
fats and oils in terms of different melting points
• To explain what hydrogenated and trans fats are
• To define rancidity and distinguish
2
 LIPIDS
• Triglycerides
– fats (fats and oils) in food
– classified as “saturated fats”
and “unsaturated fats”
according to the prevalent
kind of fatty acids they
contain
• Phospholipids
– building blocks of cell
membranes
• Steroids
– cholesterol, vitamin D,
steroid hormones (estrogen
and testosterone)
• Waxes
– indigestible
3
 TRIGLYCERIDES
• A molecule of triglyceride is formed by the bonding of one
glycerol molecule and three fatty acids molecules
• “building blocks” of triglycerides = glycerol and fatty acids

• Different fats
contain different
combinations of
fatty acids
• Different fats are
distinguished from
one another by
the prevalent fatty Glycerol and fatty
acids that they acids are the
building blocks of
contain
triglycerides

Source: Sizer and Whitney, Nutrition: Concepts and Controversies (2008), 149
4
 FATTY ACIDS
• Saturated fatty acid
– carbon chain with single carbon-carbon bonds only

• Unsaturated fatty acid

§ monounsaturated
– one double carbon-carbon bond
§ polyunsaturated
– multiple double carbon-carbon bonds
• Essential fatty acids
– linoleic acid (omega-6)
– alpha-linolenic acid (omega-3)
5
 REVIEW
• What are the main kinds of lipids?
• What are the “building blocks” of fats?
• What is the difference between saturated fats
and unsaturated fats?

6
THE FUNCTIONS OF FATS IN THE BODY
• Concentrated source of energy
• Energy storage
• Storage and transport of fat-soluble vitamins
• Sources of essential fatty acids (needed for cell
membranes, body tissues and bones, immune
system, and more)
• Body insulation
• Protection of inner organs
• Palatability of food and satiety

7
FOOD SOURCES OF FATS AND OILS
Saturated Unsaturated
• Meats, suet, lard • monounsaturated
• butter, whole milk • olives and olive oil
and partially • Peanuts, canola
skimmed (2% and
1%) milk and milk • avocado
products • polyunsaturated
• coconut oil, palm oil • fish and other seafood
• nuts and seeds
• other vegetable oils:
soybean, canola, corn,
sunflower, sesame, etc.

8
MELTING POINT OF FATS AND OILS
• Different fats have
different melting
points
• Roughly, the more
saturated the fat,
the higher its
melting point

Source: Sizer and Whitney, Nutrition: Concepts and Controversies (2008), 149 9
 REVIEW
• What are the functions of fats in the body?
• What are the main food sources of the
different kinds of fats?
• How can you distinguish saturated from
unsaturated fats in your kitchen?

10
 ARE SATURATED FATS BAD FOR YOU?
• Since the 1970s, official dietary advice brands saturated fats
as “bad fats” and recommends limiting them in your diet:

• The new Canada’s Food Guide (2019) emphasizes even more

strongly the message that saturated fats are unhealthy, hence
to be avoided
– “Choose food with healthy fats, not saturated fat.”
– it dropped the advice to choose margarines (processed fat)
• Yet, several recent metastudies have reported that there is no
scientific evidence to support this advice
• There seems to be no expert consensus on this
11
 HYDROGENATION
• Hydrogenation: industrial
process to turn unsaturated
fats into saturated
– exposure to H at high
temperature and pressure in
presence of a catalyst
– breaks double carbon bonds
and saturates the fatty acids
with hydrogen
• Food industry uses partially hydrogenated fats to
improve the texture and prolong the shelf life of
processed foods
12
 CIS AND TRANS FATTY ACIDS

Most unsaturated fatty acids are in the

cis form. A few trans fatty acids are
naturally present in milk. But industrially
processed foods may contain trans fatty
acids that are artificially made!

13
© A. Brown, Understanding Food. Principles & Preparation (Wadsworth, 2011)
 ARTIFICIAL TRANS FATS
• A side effect of partial Cis form
hydrogenation is the
production of artificial
trans-fatty acids Trans form

• These industrial by-products

raise the risk of heart disease,
inflammation, type-2 diabetes,
and possibly cancer
• In contrast, natural trans fats (which are present in
small amounts in milk and milk products) are not
associated with any negative health effect 14
 RANCIDITY
• Lipolytic rancidity
– microbes produce an enzyme (lipase) that breaks
triglycerides into short fatty acids
– characteristic flavours of butter and cheese
• Oxidative rancidity
– unsaturated fatty acids become
oxidized
– release of free radicals, which
damage cells, proteins, and DNA,
and may cause aging and diseases
– rancid smell and taste
15
 REVIEW
• What is hydrogenation?
• What are trans fats?
• How are artificial trans fats produced and why
do they end up in your food?
• What are the two kinds of rancidity?

16
THE MACRONUTRIENTS

Matthew Kinsey, Still Life with Eggs Walnuts and Copper Vessel, 2010

Part 4: PROTEINS
NATS1560 UNDERSTANDING FOOD
For class use only. Do not circulate.
 LEARNING OBJECTIVES
• To explain the molecular composition of
proteins and their “building blocks”, the amino
acids
• To explain the difference between essential,
non-essential, and conditionally essential
amino acids
• To list the diverse functions of proteins in the
body

2
 PROTEINS
• Proteins are polymers
composed of amino acids
• Amino acid = molecule
composed of an amine (-
NH2), a carboxylic acid (-
COOH), and a “side chain”
- the side chain different in
each amino acid
• Polypeptide: sequence of amino
acids
• Protein: polypeptide folded into a
specific complex shape
• Every protein is characterized by 3
 AMINO ACIDS
• Twenty amino acids are coded by DNA and
used by living organisms
• essential: the human body needs to obtain them
from food
• conditionally essential amino acids: the human
body may need to obtain them from food under
certain conditions

4
THE FUNCTIONS OF PROTEINS
• structure (e.g., keratin and collagen)
• enzymes (e.g., lactase)
• some hormones (e.g., somatotropin, insulin)
• muscle contraction (actin and myosin)
• immune system (antibodies)
• transport and cellular communication (e.g.,
hemoglobin)
• energy

5
FOOD SOURCES OF PROTEINS
• Complete sources of essential amino acids: eggs,
meat, fish, milk and milk products, soybeans,
quinoa, amaranth
Combinations of ingredients
• Incomplete sources of in dishes and diets can
amino acids: legumes or provide the full assortment
of essential amino acids.
pulses, grains, nuts,
seeds, some vegetables,
and some fruits

6
 REVIEW
• What are the “building blocks” of proteins?
• What is the difference between essential, non
essential, and conditionally essential amino
acids?
• What are functions of proteins in the body?
Give a few specific examples
• What are the main food sources of proteins?

7
MICRONUTRIENTS AND WATER

Severin Rosen, An Abundance of Fruit, 1852

NATS1560 UNDERSTANDING FOOD

 LEARNING OBJECTIVES
• To define the micronutrients and distinguish the two kinds,
vitamins and minerals
• To identify the different types of vitamins and minerals and
survey some of their main functions and food sources
– water-soluble and fat-soluble vitamins
– minerals: major minerals, electrolytes, and trace minerals,
• To define micronutrient deficiencies, and identify several
major examples
• To define the two types of malnutrition, undernutrition and
overconsumption, and explain how they are related to
micronutrient deficiencies
• To list the functions of water in the human body
• To define solutions and the pH, or acid-base, scale
2
 MICRONUTRIENTS
• Nutrients needed by the body in smaller amounts than
the macronutrients (milligrams or micrograms)
• Naturally provided in adequate amounts by a diet that
provides sufficient calories from a variety of whole (i.e.,
non refined) foods and fresh fruits and vegetables
• Do not provide energy to the body
• Two main kinds: vitamins and minerals
• Vitamins: organic compounds produced by plants and
animals
• Minerals: elements absorbed (as parts of compound
molecules) from the soil by plants, from plants by
animals
• Micronutrient deficiencies: one form of malnutrition
3
 THE DOUBLE BURDEN OF
MALNUTRITION
• Nearly 690 million people are malnutrition
hungry, or 8.9% of the world
population overconsumption:
excess calories
• an estimated 2 billion people in
undernutrition:
the world did not have regular insufficient
access to safe, nutritious and calories and
sufficient food in 2019. proteins

• In 2016, 54 million children and micronutrient

more than 1.9 billion adults deficiencies
were overweight. Of these, over
600 million adults were obese
• Underfed and overfed can both also suffer from micronutrient
deficiencies
• Many nations, communities, households, and even individuals
across the world today suffer from both undernutrition and
overconsumption
4
 EXERCISE
• Many people today have diets that provide too many
calories but not enough __________
1. energy
2. macronutrients
3. micronutrients
4. chocolate
• Today, the poor suffer from
undernutrition, while the rich
suffer from overconsumption.
q True
q False

5
 VITAMINS
Essential organic nutrients needed in tiny amounts to
make possible the processes of body’s metabolism
FAT-SOLUBLE VITAMINS WATER-SOLUBLE VITAMINS
Stored in liver and fat tissues, Travel freely in bloodstream,
excess is readily excreted
excess may build up to toxic levels
• Vitamin A • B complex
– thiamin (B1), riboflavin (B2),
• Vitamin D niacin (B3), pantothenic acid
• Vitamin E (B5), B6, biotin (B7), folate
(folic acid, B9), B12.
• Vitamin K
• Vitamin C

© Sizer, Whitney, Piche, Nutrition. Concepts and Controversies (Nelson, 2012),

 VITAMIN A
• Group of compounds: retinol, retinal, retinoic acid
− Food sources: liver, fish, eggs, butter, fortified milk
• Provitamins A: beta-carotene and other carotenoids
− Food sources: orange and dark green fruit and veggies
• Needed for
− vision
− immune system
− skin and inner linings
− bones and teeth
− gene expression
− reproduction
7
 EXERCISE
• If you eat too much
fresh fruit you may
overdose in vitamin C
qTrue
qFalse
• Excessive amounts of
vitamin D supplements are
toxic
qTrue
qFalse
8
 VITAMIN A DEFICIENCY (VAD)

Vitamin A Deficiency affects 250 The World Health Organization is

million of undernourished children working to reduce it with programs
and adults every year around the of Vitamin A supplementation and
world, causing blindness, infections, fortification of staple foods, such as
and infant mortality! flour, milk, oil, and sugar.

9
 VITAMIN D
THE SUNSHINE VITAMIN
• Actually, a steroid hormone
• Synthesized by the skin with the help of
sunlight
• Ability to synthesize depends on skin tone
and decreases with age
• Food sources: salmon, shrimp, sardines,
egg yolk, fortified milk
• Needed for
− bone and teeth formation
− immune system
− brain
− many other organs and functions
• In children, vitamin D deficiency
causes rickets
10
 VITAMIN E
• Antioxidant, especially
for lungs and blood cells
• Present in small amounts
in many foods
• Deficiency is rare
VITAMIN K
• Produced by gut bacteria
• In green veggies, soybeans, canola
• Necessary for blood to clot
• Assists in bone formation along
with vitamin D
• Deficiency is rare (newborns,
medical conditions, antibiotics)
11
 VITAMIN C B VITAMINS
• Ascorbic acid = anti- • Coenzymes
scurvy vitamin • In beans, whole grains,
• Antioxidant, maintains potatoes, asparagus, etc
collagen, protects • B12 only in animal food
against infections, helps • Thiamin (B1) deficiency:
iron absorption beriberi
• Fresh fruit and • Niacin (B3) deficiency:
vegetables provide pellagra
ample amounts
• Folate deficiency:
• Vitamin C deficiency:
neural tube defect
scurvy
12
 REVIEW
• What are the fat soluble vitamins?
• What are the water soluble vitamins?
• How many kcal/g does Vitamin A provide?
• What is the cause of the
following disease?
− Beriberi
− Scurvy
− Pellagra
− VAD
13
 MINERALS

MAJOR MINERALS TRACE MINERALS

• calcium • iron • sulfur
• phosphorus • zinc • chromium
• magnesium • iodine • copper
• sodium • selenium • manganese
• chlorine (chloride) • fluorine (fluoride) • molybdenum
• potassium
14
 SOME IMPORTANT MINERALS
• Calcium and phosphorous, primary components
of bones and teeth
• Iron, component of hemoglobin
• Sodium and potassium, needed for fluid balance
in and between body cells, and muscle and nerve
functions
• Chlorine (chloride) and magnesium, essential to
metabolism
• Zinc, needed for health of skin, nervous system,
immune system, reproductive system, and more
15
 EXERCISE
• What is a micronutrient deficiency?
• Give a specific example of a micronutrient
deficiency
• Is the following statement correct? Explain.
“Because they eat large amounts of milled
rice, Asians are still prone to beriberi.” (Older
versions of UF, 210)

16
 WATER
• The body needs a steady
supply of water
• Water is the basis of all body
fluids, and is contained in
muscles, fat, tissues, and
bones
• is a solvent needed for many
biochemical activities
• needed for the elimination of
waste from the body
• regulates body temperature
• lubricates joints and cushions
organs
17
 SOLUTIONS, ACIDS, AND BASES
• Solution: mixture in which the molecules or
ions of a substance (solute) are dissolved in a
liquid (solvent)
• Water is a good solvent because its molecules
are polar (electric charge not equally
distributed)
• Acid: substance that releases H+ ions when
dissolved in water, giving it a sour taste
• Base or alkali: substance that accepts H+ ions
18
 THE pH SCALE
• Pure water is the standard of acidity
• pH: measure of acidity (or concentration of H+)

19
 REVIEW
• What percentage of the • What is the approximate pH
human body, approximately, of the following substances?
is made of the following • Water
substances? • Hydrochloric acid
• Water • Lemon juice
• Proteins • Egg white
• Lipids • Vinegar
• Minerals • Yogurt
• Ammonia

20
 FOOD IN THE BODY

Annibale Carracci,
The Bean Eater,
1580.

SC/NATS1560 3.00 UNDERSTANDING FOOD

 LEARNING OBJECTIVES
• To define and explain the main parts of the
human digestive system and the process of
digestion
• To define and explain the main parts of human
metabolism
• To define and explain the role of enzymes
• To define and explain the action of insulin and
glucagon
• To define and explain Type 1 and Type 2 diabetes
• To define and explain the main parts of the
urinary system
2
 WHAT FOOD IS FOR
• Our body disassembles the molecules of
macronutrients into molecular “building
blocks” (digestion)
– molecular building blocks: monosaccharides,
amino acids, fatty acids, and glycerol
• It then uses the molecular building blocks to
– assemble them into body molecules
– disassemble them into CO2 and H2O to release
energy

3
 FOOD IN THE BODY
• Digestion
• Absorption
• Metabolism
– all the
physical and
chemical
processes
occurring in
the cells of a
living
organism
• Excretion
4
THE BODY’S USE OF FOOD ENERGY
• Basal metabolism: minimal expenditure of energy
needed by the body to stay alive
– on average, about 2/3 of total energy needs
– changes with age, highest in 1st year of life, stable
between ages 20 and 50, declines after 50
– mostly used by brain (20%), and liver, heart, and
kidneys (38%), minimal use by body fat
• Physical and mental activity
• The “thermic effect of food” (about 10% of the
metabolizable energy from food)
– energy lost as heat during digestion and metabolism
– a little energy is used to maintain body temperature
when environment is too hot or too cold
5
 METABOLIC PROCESSES
• Metabolism: all the chemical reactions by means of
which an organism uses food molecules to live
– maintain basic life functions (heart, lungs, liver, brain,
kidneys, etc)
– build new molecules for its organs, tissues, and other needs
– keep warm
– use muscles for deliberate physical activity
• Metabolic pathways: sequences of reactions leading
from absorbed nutrients (substrates) to some final
products (other compounds and energy)
• Specific metabolic pathways are enabled or disabled by
specific enzymes
6
 ENZYMES
• Enzymes are biological catalysts
• they enable or speed up metabolic reactions
by lowering the activation energy

From “Enzymes” at sciencetechstudy.com

7
 EXERCISE
• Which of the following
molecules are absorbed
and metabolized by the
body?
a. triglycerides
b. proteins
c. amino acids
d. polysaccharides • Which of the following
molecules are digested by
our gastrointestinal system?
a. oligosaccharides
b. glycerol
c. fructose
d. polysaccharides
8
 THE HUMAN DIGESTIVE SYSTEM
Digestive tract organs Organs that aid digestion
mouth chews and mixes
food with saliva salivary glands secrete
the enzyme amylase
esophagus moves food down
into stomach through peristalsis liver manufactures bile,
stomach synthesizes glycogen and
adds hydrochloric acid and blood proteins, stores iron
enzymes (e.g., pepsin) and and vitamins, etc.
churns food into chyme
small intestine gallbladder stores bile
(duodenum, jejunum,
ileum) uses enzymes from
pancreas to digest nutrients,
and absorbs the digested pancreas secretes
molecules through the villi into enzymes (lipases, proteases,
blood and lymphatic vessels and carbohydrases) for the
small intestine, and the
large intestine (cecum, hormones, insulin and
colon, rectum) absorbs glucagon that regulate
water and minerals, houses glucose levels in the blood
intestinal flora (friendly
bacteria) that complete
digestion, eliminates waste 9
 MOUTH AND STOMACH
• In the mouth, food is chewed
and mixed with saliva
• Saliva enzymes begin breaking
down starch
• Swallowing triggers
peristalsis, which moves food
through the esophagus
• In the stomach, food is
churned and mixed with
gastric juices, and turned into
chyme
• Gastric acid (hydrochloric
acid) unfolds proteins, gastric
enzyme (pepsin) clips
polypeptides into smaller
strands, fats separate from
the watery mixture 10
SMALL AND LARGE INTESTINE
• In small intestine, bile (produced in
liver, stored in gallbladder)
emulsifies fat
• Enzymes from pancreas and
intestinal cells (proteases, lipases,
carbohydrases) digest fats,
proteins, and starch and
disaccharides
• Simple sugars, fatty acids and
glycerol, amino acid, vitamins, and
minerals are absorbed through the
villi into bloodstream and lymph
• In large intestine, colon bacteria
ferment some of the fibre
• Fermentation products, water, and
minerals are absorbed
• Residues (waste products and
bacteria) are excreted as feces 11
 REVIEW
• What are the main organs of • What organs perform the
the digestive tract? following functions?
• What are the main organs that − peristalsis
aid digestions? − transformation of food into
chyme
− secretion of digestive
enzymes, insulin, and glucagon
− storage of bile
− production of bile
− synthesis of glycogen
− storage of fat-soluble vitamins
− absorption of most nutrients
© Toby Bridson
− absorption of water

12
 THE LIVER
• Largest organ in the body
• converts simple sugars into
glycogen
• converts non-carbohydrates into
glucose
• makes cholesterol and other
lipids

• stores iron and fat-soluble vitamins

• synthesizes amino acids into proteins
for blood
• converts amino acids into variants
• removes dead blood cells, wastes,
toxins and bacteria from bloodstream
• filters out toxins, e.g. alcohol
 HORMONES AND NUTRITION
• The level of glucose in the bloodstream must
remain within a narrow range (70-100 mg/dl)
− glucose needed for the central nervous system
− too much glucose damages blood vessels
• The level of glucose in the bloodstream is
regulated by two hormones secreted by the
© Sebastian Kaulitzki pancreas, insulin and glucagon
• When blood glucose is on the rise, insulin
signals the cells of the body to increase
their uptake of all nutrients
• When blood glucose starts to drop,
glucagon signals the liver to start breaking
down glycogen, fat, and proteins
• Diabetes mellitus, type 1: pancreas
produces too little insulin
• Diabetes mellitus, type 2: insulin
receptors in cells do not function normally
14
 THE URINARY SYSTEM
• Kidneys
− clean the blood filtering out
waste products and toxins
− regulate the amount of water
(therefore, the amount of blood)
in the body
− heart and hypothalamus send
signals through changing levels of
antidiuretic hormone (ADH)
− regulate the concentration of
ions and the pH of the blood
• Ureters channel urine out of the kidneys into the bladder
• Bladder holds the urine
– until built-up pressure sends the signal to urinate
• Sphincter relaxes to let urine out through the urethra
15
 REVIEW
• What are the functions of the liver?
• What hormones regulate the level of glucose in the
bloodstream?
• What are Type 1 and Type 2 diabetes?

Bye bye! • What are the main organs

of the urinary system?
• What are the functions of
the urinary system?

16
FOOD GONE BAD

NATS1560 UNDERSTANDING FOOD

For class use only. Do not circulate.
 LEARNING OBJECTIVES
• To define food safety, and identify the leading causes of
foodborne illnesses in Canada
• To name some common endogenous toxins in
vegetables, animals, and mushrooms
• To identify the most common and dangerous biological
contaminants
• To identify the most effective ways to protect oneself
from foodborne illnesses
• To identify common chemical contaminants and their
sources, and explain bioamplification
• To define allergens and name the most common ones
 FOOD SAFETY
• Practices of food production, processing, and handling,
and storage aimed to ensure that the food is free from
harmful substances (endogenous toxins and
contaminants)
ENDOGENOUS TOXINS IN VEGETABLES
• Solanine, glycoalkaloid in plants of
Solanaceae family (potatoes, tomatoes,
eggplants, peppers, etc.)
• Alkaloids, e.g., caffeine and theobromine
• Oxalic acid (rhubarb, spinach, collards,
kale, broccoli, beets, etc.)

• Amygdalin and other cyanide-

producing compounds (cassava,
apricot kernels)
• Protease inhibitors (raw beans)
• Phytoestrogens (soy beans)
 TOXINS IN MUSHROOMS AND
ANIMALS
• Mushroom toxins,
– e.g., in Amanita verna aka
(“Destroying angel”)
• Puffer fish or fugu,
(tetrodotoxin)
• Shellfish toxins, or
contamination by “red tide”
– Paralytic Shellfish Poisoning,
PSP (saxitoxin)
– Amnesic Shellfish Poisoning,
ASP
– Diarrhetic Shellfish Poisoning,
DSP
 REVIEW
• What are the food sources of the following
toxins?
a. tetrodotoxin
b. protease inhibitors
c. theobromine
d. solanine
e. saxitoxin
f. oxalic acid
g. amygdalin
BIOLOGICAL CONTAMINANTS

• Bacteria
• Fungi
(mycotoxins)
• Viruses
• Parasites
• Prions
 BACTERIA, FUNGI, VIRUSES,
AND PARASITES
• BACTERIA • MYCOTOXINS
• Campylobacter – Ergot (sclerotia in rye)
• Clostridium perfringens – Aflatoxins
• Clostridium botulinum – Smuts and rusts
• Escherichia coli • Viruses
• Listeria monocytogenes – Norovirus, or Norwalk
• Mycobacterium – Hepatitis A
tuberculosis • PARASITES
• Salmonella – Roundworms (e.g., Trichinella
spiralis)
• Shigella
– Tapeworms
• Staphylococcus aureus
– Giardia lamblia (giardiasis, or
• Vibrio cholerae beaver fever)
• Yersinia enterocolitica – Entamoeba histolytica
 REVIEW
• Assign the following biological contaminants to their categories:
Biological contaminants
Categories e. Tapeworm
a. virus f. Hepatitis A
b. bacterium g. Aflatoxin
c. mycotoxin h. Staphylococcus aureus
d. parasite i. Salmonella
j. Entamoeba histolytica
k. Ergot
l. Vibrio cholera
m. Giardia lamblia
n. Listeria monocytogenes
o. Clostridium botulinum
p. Trichinella spiralis
q. Campylobacter
r. Escherichia coli
s. Yersinia enterocolitica
THE WALKERTON TRAGEDY
• May 2000, E. coli O157:H7
contamination of Water Public
Utility in Walkerton, ON
• 2300-2500 cases, 7 deaths
• Public Utility Commission
manager and foreman found
guilty of negligence in
discharging their duties to keep
public water safe

?
 CANADA’S 2008 LISTERIOSIS
OUTBREAK
• 57 cases of
listeriosis, 22
deaths
• caused by
contaminated
packaged meats
from a Maple Leaf
Foods plant in
Toronto
2012 XL FOODS BEEF RECALL
 … all of them!

“Hand print on a large TSA plate

from my 8 1/2 year old son after
playing outside”, by Tasha Sturm,
Cabrillo College, June 2015.
It shows colonies of bacteria and
fungi, most of which are harmless,
some even beneficial, and some
may be harmful.
 ARE ANTIBACTERIAL PRODUCTS GOOD?
• Many antibacterial products (soaps, detergents, wipes, etc.)
use triclosan and similar chemicals as active ingredients
• The is no evidence that these products are more effective
than regular soap and water
• They promote the growth of
antibiotic-resistant bacteria
• They are harmful to
ecosystems and very likely
to human health too
• The hand-sanitizer Purell™
is an alcohol-based gel. It
does not contain triclosan
or similar chemicals
http://www.smithsonianmag.com/science-nature/five-reasons-why-you-should-
probably-stop-using-antibacterial-soap-180948078/?no-ist
 FOOD SAFETY PRECAUTIONS
• Wash hands before handling food
• Do not eat food picked up from the
floor
• Wash cutting boards and kitchen
equipment carefully, especially if used
for raw meat
• Cook pork and ground beef thoroughly
(at least 70°C)
• Wash fruits and vegetables
• Do not let perishable food sit at room
temperature for more than a few
minutes
• Minimize eating raw eggs
• Do not use antibacterial products
• Demand that food manufacturers and
public officials give public health
priority over private interests
 REVIEW
• What are the five most common causes of
foodborne illnesses in Canada?
• What can you do to protect yourself from
these illnesses?
 BSE, OR MAD COW DISEASE
• Bovine Spongiform Encephalopathy (BSE), one of the
Transmissible Spongiform Encephalopathies (TSE), like
scrapie in sheep and Creutzfeldt-Jakob Disease (CJD) in
humans
• caused by prions, self-replicating misfolded proteins in
brain and spinal tissue
• Late1980s-1990s, BSE epidemics in UK caused an
outbreak of variant Creutzfeldt-Jakob Disease (vCJD),
− 177 cases of vCJD in UK, about 20 in France, several in Human prion protein structure.
Ireland, Italy, Spain, USA, and Canada Source: cchem.berkeley.edu

• transmitted to cattle by feed containing

protein supplements made from waste
sheep and cattle tissue (now banned
for ruminants)
• transmitted to humans through
consumption of infected cattle products
containing brain and spinal tissue

British Minister of Agriculture in 1990 assuring the public

that beef was “completely safe” (Source: BBC News)
 CHEMICAL CONTAMINANTS
Unintentional (industrial waste) Intentional
• Mercury • Pesticides
– methylmercury – Insecticides
• Heavy metals • organochlorines (dioxin,
– Al, Pb, As, Cd, etc. DDT), organophosphates,
carbamates
• Fire retardants (PBDEs) – Fungicides
• Polychlorinated – Herbicides
biphenyls (PCBs) and • 2,4-D, atrazine, glyphosate
related compounds • Hormones
(furans and dioxins) – synthetic estrogen
– rBGH, or rBST
• Antibiotics
PERSISTENT ORGANIC POLLUTANTS
• Persistent Organic Pollutants (POPs): toxic chemicals that, once
released in the environment, persist for a very long time and
get widely distributed, causing damage to humans and
ecosystems
– POPs can cause cancer, allergies and hypersensitivity, damage to the
central and peripheral nervous systems
– Some POPs are considered endocrine disrupters, which altering the
hormonal system, and can damage the development, reproductive
system, and immune systems of exposed individuals
• Since 2004, the Stockholm Convention on Persistent Organic
Pollutants has banned an increasing number of POPs:
− certain pesticides, as DDT and others
− industrial chemicals and their by-
products, like PBDEs, PCBs, dioxins,
furans, and others
− PFOA is currently under review
 BIOAMPLIFICATION
• POPs are absorbed by
organisms
• Bioaccumulation or
bioconcentration: build-
up of the pollutant in the
tissues of an organism
• Bioamplification or
biomagnification:
increased concentration
of the substance as it
moves up the food chain
 TOXINS FROM
COOKING AND PACKAGING
• Sodium nitrates and sodium nitrites
(nitrosamine)
• Polyaromatic hydrocarbons (PAHs)
and other compounds from smoking
and charring
• Plastic monomers and plastic
additives (phtalates)
• Bisphenol-A, or BPA (in polycarbonate
plastic and epoxy resins)
• PFOA (perfluorooctanoic acid, in
Teflon cookware)
 REVIEW
• What are the sources of he following chemical
contaminants?
a. Mercury
b. PBDEs (polybrominated diphenyl ethers)
c. PCBs (polychlorinated biphenyls), furans, and
dioxins
d. PFOA (perfluorooctanoic acid)
e. Nitrosamines
f. BPA (bisphenol-A)
 ALLERGENS
• Allergen: substance that is normally safe to eat, but in
some people triggers an anomalous immune response
• Allergens are most commonly found in
– peanuts
– nuts
– soy
– fish, shellfish,
and crustaceans
– eggs
– milk
• Celiac disease
– gluten (in
wheat, barley,
rye, and oat
products)
 EXERCISE
• What are the different kinds of
toxins and contaminants that
may be in our food and water?

• What can we do to protect

ourselves and our families from
these health hazards?
© Toby Bridson
PRESERVING
FOOD
1. Drying,
Salting, Smoking,
Sugaring, Pickling
and Curing
NATS1560 UNDERSTANDING
FOOD
For class use only. Do not
circulate.
 LEARNING OBJECTIVES
• To define food spoilage, and identify its causes and the
variables that control it
• To define and the explain some pre-industrial and
industrial methods of food preservation, and to review
some of their history, advantages, and disadvantages
– methods that work by dehydration: drying, salting,
sugaring
– pickling, and how it differs from “quick pickling”
– canning
– refrigeration
– pasteurization
– irradiation
 PRESERVING FOOD
• All foodstuff is perishable
• Food preservation: processing of food to delay and
minimize spoilage
• Main causes of spoilage: microbes (bacteria, yeasts,
molds), enzymatic reactions, oxidation
• Variables that favour spoilage: moisture,
temperature, acidity, exposure to oxygen
• Preservation consists of controlling the variables
that favour spoilage
• All human cultures have developed methods of
food preservation
• Industrialization has increased the demand for
preserving methods, made old methods more
efficient and cheap, and added more methods
 FOOD PRESERVING METHODS
PRE-INDUSTRIAL INDUSTRIAL
• Drying • Canning
• Smoking • Refrigeration and freezing
• Salting • Pasteurization
• Sugaring • Irradiation
• Pickling • Preserving additives
• Cooking • Vacuum packaging
 DRYING, SALTING, SMOKING
• Dehydration: removal of water
• Traditionally, by open air, sun, and heat
• For fruits, tomatoes, mushrooms, fish, meat
• Often in combination with salt and smoke
• Addition of salt, a hydrophilic (water-loving) or
hygroscopic (water-absorbing) substance
Dehydration will inhibit Smoke also contains antibacterial
the growth of pathogens. and antioxidant substances.

• Industrial drying:
− tunnel drying
− drum drying
− spray-drying
Timucuan smoking game, 1562
 SUGARING
• Sugar, like salt, reduces the moisture
available for microbial life
• Ancient Greeks and Romans used
honey and concentrated grape juice
as sweeteners and preservatives
• In Asia, sugar extracted from sugar
canes was used as a drug, spice, and
luxury item From sugar.org/sugar/history

• 1500s, Portuguese and Spanish traders imported sugar cane to

South America and Caribbean
White sugar is pure sucrose extracted • 1600s-1700s sugar industry grew with slave
and refined from molasses, which is
boiled sugar cane or sugar beet juice.
trade and its unspeakable human costs
Raw sugar is crystallized molasses.
Brown sugar is white sugar with some
• 1800s, slave labour and industrial refining
molasses added back to it. made sugar a cheap mass commodity
• Only then did jams, marmalades, and jellies
become a popular way to preserve fruit
- cooked fruit + sugar + pectine (naturally
present or added)
 PICKLING AND CURING
By fermentation or curing By direct acidification (or “quick
• Fruits, vegetables, or meats pickling”)
are salted or brined • Soaking in a vinegar solution
• Then sealed in a container or • Flavoured with sugar, garlic,
otherwise left to the action of spices
beneficial bacteria and yeasts • Examples: common pickles,
• Fermentation by beneficial carrots, okra, beans,
bacteria (e.g., Leuconostoc mushrooms, pears, peaches,
mesenteroides and etc.
Lactobacillus plantarum) or
yeast
• Development of lactic acid and
aromatic compounds (complex
flavours and textures)
• Examples: cabbage
(sauerkraut and kimchi),
olives, cucumbers, salami,
chorizo, etc.
 REVIEW
• What are the main causes of food spoilage?
• What variables favour food spoilage?
• How do drying, salting, and sugaring slow
down spoilage?
• What is the difference between pickling and
“quick pickling”?
PRESERVING
FOOD
2. Canning,
Refrigeration and
Freezing,
Pasteurization,
Irradiation
NATS1560 UNDERSTANDING
FOOD
For class use only. Do not
circulate.
 A THUMBNAIL HISTORY OF CANNING
• In pre-industrial times, some cooked food was
kept in sealed containers
– pie crusts
– potted food and terrines, pâtés, sealed with fat
• 1810, Nicholas Appert won a French army’s
contest a new method of food preservation
– large jars sealed with cork lids and wax
• Englishman Brian Donkin replaced jars with
tin-coated iron cans (up to 2 kg)
– adopted by British Navy and military everywhere
• 1850s, industrial canning and long-distance
shipping became affordable for home use
– tomatoes, peas, peaches
– meat from Argentina, US, and Australia
– fish from BC and Canada’s East Coast, Washington,
Oregon, California
• Late 1800s, mass-produced glass jars with air-
tight lids made home canning of fruit and
vegetables popular
 CANNING
• Food is placed in airtight containers and sterilized with high heat
• Some foods are blanched before canning
• Canning industry today can mass-produce canned foods very
efficiently and sell them at a low price
• Revival of home canning in Canada for home consumption, farmers
markets, restaurants, and small food-processing companies
• To prevent the risk of botulism (from the bacterium Clostridium
botulinum), low-acid foods (pH > 4.6) must be heated at 121 °C for
10-20 min

From “Home Canning Safety”, Health Canada, canada.ca/en/health-canada/services/general-food-safety-tips/home-canning-safety.html

 REVIEW
• How does canning preserve food?
• What foodborne hazard can carelessly
canned food present?
A THUMBNAIL HISTORY OF REFRIGERATION
• Cold preserves food by slowing down
microbial growth and enzymatic action
• Cool caves and cellars, and snow and ice
from mountains used in the past
• 1800s-early 1900s, ice-harvesting industry
in Canada and US
• Ice-blocks refrigerated trains and cargo C. Gagnon, The Ice Harvest, 1934
ships allowed for long-distance food trade
• 1850s, invention of heat pump and mechanical
refrigeration
• 1870s, ammonia-refrigerated units and cold-
storage plants
• 1910s-1950s, large electric refrigerators
(Kelvinators), use of CFCs
• 1950s, electric refrigerators became affordable
home appliances for all
Domestic icebox, around 1890 • Today, trans-national cold chains allow storage and
long-distance shipping of all sorts of foods in global
supply chains
 FREEZING
• Industrial cold chains allowed the growth of the frozen food
industry
• Freezing does not kill most microbes, but inhibits their
growth and slows down enzyme action
• Fast freezing helps preserve food quality by preventing the
formation of large ice crystals
• Air-blast freezing: -12 ⁰C air blast, followed by slower
cooling to -20 ⁰C
• Immersion freezing: for chicken and turkey, with brine,
sugar and water, propylene glycol (antifreeze), followed by
centrifuging to remove liquid
• Freeze-drying or lyophilization: frozen food (peas, coffee)
placed in a vacuum chamber and slightly heated, water
vapour removed
 CFCs AND OZONE DEPLETION
• Chlorofluorocarbons (CFCs), from
1930s to 1987 widely used as
refrigerants and aerosol
propellers
– POPs that cause the breakdown
of ozone, O3 in the stratosphere
• Ozone absorbs harmful
radiation, especially UVB
• Montreal Protocol, Oct. 16,
1987: international treaty for
the phasing out of CFCs and
other ozone-depleting
Ozone hole over Antarctica substances
 PASTEURIZATION
• Named after Louis Pasteur (1822-
1895), pioneer of microbiology
• Heat treatment to kill microbes and
de-activate enzymes while minimizing
flavour change
• Applied mostly to milk, juices, beer

• Batch pasteurization, approx. 65

ᵒC for 30-35 min
• HTST, 75-80 ᵒC for 15 sec
• UHT, 130 ᵒC for 1-3 sec
• Since 1991, only milk that is
pasteurized can be sold in Canada
 IRRADIATION
• Food exposure to ionizing
radiation (x-rays, gamma rays,
electron beams)
• A spin-off of the nuclear
industry
• It damages the DNA of
organisms
• To kill microbes and pests
• To delay ripening and sprouting Diagram of a food irradiation facility

• It can also damage food cells and proteins,

cause severe losses of vitamins and
alterations of texture and taste, and create
harmful substances
Radura, the international • In Canada, only allowed on potatoes,
symbol meaning “treated
with irradiation”. onions, wheat, flour, spices, and
dehydrated seasoning preparations.
 REVIEW
• How does refrigeration slow down spoilage?
• What global environmental issue was caused by
industrial refrigeration?
• What is pasteurization?
• What are the different types of pasteurization?
• How does irradiation help to preserve food?
• What methods of food preservation work by
dehydration?
PREPARING FOOD

NATS1560 UNDERSTANDING FOOD

 TEMPERATURE AND HEAT
• Temperature: measure of the hotness or coldness of a body
- in the atomic theory of matter, temperature = average kinetic
energy of molecules
• Heat: energy transferred from a hot to a cold body
• Heat transfer Metals are good conductors
of heat. Glass, ceramic and
- convection: by movement of plastic are good insulators.
fluids
- conduction: by contact, no
movement of bulk matter
- radiation: by propagation of
electromagnetic waves through
space
TEMPERATURE SCALES
In case you need
the conversion
formulas, they
are:
• F = 9/5 C + 32
• C = 5/9 (F-32)
• K = C + 273.15
 TEST PRACTICE
3. Which method of heat 4. What happens when you
transfer works by transfer heat to food?
movement of bulk a. The kinetic energy of the
matter? (Choose the molecules increases
best answer) b. The kinetic energy of the
a. Convection molecules decreases
b. Conduction c. The thermal energy of
c. Radiation the molecules decreases
d. All the answers d. Molecular motion slows
down
 HEATING SOURCES FOR COOKING
• open fire or
fireplace
• brick oven
• coal stove
• gas stove
• electric range and
oven
• microwave oven
• induction stove
 COOKWARE AND COOKING METHODS
• earthenware, ceramics, pyrex
• cast iron
• stainless steel
• copper
• aluminum
• enamel-coated iron or steel
• Teflon (chlorine-based plastic)
• roasting, grilling, broiling,
• baking
• boiling, simmering, poaching,
braising, steaming
• frying, sautéing
• pressure cooking
• microwaving
 HOW COOKING CHANGES FOOD
• Cooking improves taste and texture by
− blending flavour molecules
− intensifying flavour by drawing out water
− caramelization (sugars at high temperature)
− Maillard reactions (sugars + amino acids at
high temperature)
− denaturing proteins (softening of collagen in
meat, coagulation of egg whites)
− thickening liquids with starches (slurry, roux)
 COOKING AND NUTRITION
• Cooking affects the nutritional quality of food
• It makes more calories available to be absorbed and
metabolized
• It decreases the energy cost of digestion
• It makes food safer and slows down spoilage by killing
microbes and deactivating enzymes
• It changes the texture of food, e.g. making tough foods
softer
• It changes the flavour of food
• It can also cause loss of vitamins (especially C and B) ,
degrade fats (above smoke point), and create toxic
compounds
 TEST PRACTICE
5. Which of the following 6. How does cooking
materials is the best change the nutritional
thermal insulator? quality of food?
a. Cast iron a. Making fewer calories
b. Copper available
c. Stainless steel b. Making more calories
d. Ceramics available
c. Making more
micronutrients available
d. Changing carbohydrates
into fats
FOOD AND FERMENTATION
Part 1

José Escofet,
Bread, Cheese
and Wine on
Table, 1993

SC/NATS1560 3.0 UNDERSTANDING FOOD

 LEARNING OBJECTIVES
• To define fermentation and distinguish the scientific
definition from the common usage of the word
• To define the difference between alcoholic fermentation and
lactic acid fermentation
• To highlight the uses of fermentation for food processing and
preservation
• To describe milk as a food and as a raw ingredient, and
identify the main fermented and non-fermented milk
products
• To name the most useful lactic
acid bacteria
• To describe cheesemaking as an
example of the use of
fermentation
• To distinguish cheese from
“processed cheese”
 WHAT IS FERMENTATION?
• Scientific definition: anaerobic • Used to process and preserve
metabolic process (= energy food
production in absence of • In common speech,
oxygen) occurring in bacteria, “fermentation” refers to the
yeasts, and oxygen-deprived desirable transformation of
muscle cells food and drinks by the
• It transforms organic beneficial action of microbes
molecules (mostly sugars, but − it can occur both in absence or
also alcohol and proteins) into presence of oxygen (anaerobic
other molecules or aerobic fermentation)
− alcoholic fermentation: ethyl
alcohol + CO2
− lactic acid fermentation: lactic
acid
− acetic fermentation: acetic
acid
FERMENTATION IN FOOD PROCESSING
AND PRESERVATION
• Humans have been using a variety • Microbes or microorganisms:
of fermentation processes to bacteria, yeasts, protozoa, fungi,
produce fermented foods and algae, amoebas, and slime molds
drinks • Fermentation: manipulation of
• Fermented foods and drinks have environmental conditions to
been important parts of the diet − promote the growth of
of every human culture beneficial microbes (beneficial
• In the 19th century, Louis Pasteur bacteria and yeasts)
and other scientists − inhibit the growth of harmful
− discovered that both fermentation microbes
and decay are results of the • The food industry today applies
action of microbes on organic microbiology to modify ancient
molecules fermentation practices,
− gave birth to the science of − to adapt them to industrial
microbiology production, long-term storage
and large-scale distribution
− to manufacture new marketable
products
 REVIEW
• What are the two main kinds of
fermentation?
• How does the common usage of
the term fermentation differ
from the scientific definition? Clara Peeters, Still Life with Cheeses,
Artichoke and Cherries, c.1625

• How did humans use

fermentation in the past?
• How do we use fermentation
today?

Floris Van Dijck, Still Life with Cheeses, c.1620

 MILK
• In our diet, mostly from cows
– also from goats, sheep, buffalos, etc.
• Composition of cow milk by weight:
– 87% water
– 5% sugar (lactose)
– 3.8% fat
– 3.5% proteins (casein and whey
protein)
– vitamins (A, B complex)
– minerals (mainly calcium)
– enzymes
– many other molecules (flavour)
• Other milks have similar
composition
 MILK PRODUCTS
Unfermented
• Cream: half-and-half (12%
fat), table (18%), whipping
(35%)
• Butter (sweet cream butter)
• Ice cream or gelato
Fermented
• Sour cream
• Cultured butter
• Buttermilk
• Yoghurt
• Cheese
 CURDLING AND FERMENTATION
• Curdling:
− addition of acid to milk makes
casein molecules clump
− curds separate from whey
• Lactic acid fermentation:
− lactic acid bacteria transform
lactose into lactic acid
− lactic acid curdles the milk and
prevents the growth of
harmful microorganisms

• various species of lactic acid

bacteria from the genera
Lactobacillus, Lactococcus,
Streptococcus, and Leuconostoc
 REVIEW
• What are the two main nutrients
by weight in in milk?
• What are the genera of bacteria
most commonly used for lactic-
acid fermentation?
Johannes Vermeer, The Milkmaid, c.1660

• How are ice cream and yogurt

similar? How do they differ?
• Curdling and fermentation are
the same process. True or
false? © Joel Penkmans
 MAKING CHEESE
• Lactic-acid bacteria turn lactose into lactic acid, which causes
curdling (curds and whey)
• Rennet enzymes (chymosin) enhance the formation of curds and
whey
• Curds are further processed in many different ways—strained,
salted, cooked, kneaded, stretched, pressed, aged, etc.—to obtain
different kinds of cheese
– curds in brine: feta
– kneaded and stretched curds in hot water: mozzarella, provolone
– curds heated at low temperature and piled or pressed: manchego,
cheddar, etc.
– curds heated at higher temperature and pressed: asiago, gruyère,
emmental, parmesan, etc.
– curds inoculated with moulds: camembert, roquefort, stilton,
gorgonzola, etc.
• Whey can be used to make ricotta (= “cooked again”)
 EXERCISE

www.youtube.com/watch?v=AqFqTJJRNPY

Is this how you make real ricotta?

 Some aged cheese wheels, as for example
gouda, are waxed on the outside. Others
have a dehydrated outer shell called a
“rind”. The cheesemaker maintains the
rind, either allowing one type of edible
How can cheese be mold to flourish on it, as for brie, or wiping
aged so long, but when it regularly with salt water, as for cheddar.
it’s in my fridge it goes Once you slice the cheese and stop
quickly mouldy? maintenance, the cheese can be attacked
by molds from the environment.
 PROCESSED CHEESE
• “Cheese product”, mass-produced from
cheese and “milk ingredients” with the
addition of emulsifiers, colours, and
other additives
• cheaper, longer shelf life, melts evenly
• often pre-sliced and pre-packaged

• patented by James L. Kraft in

Chicago in 1916
• founder of Kraft&Bros Co.
• now Kraft&Heinz Company,
one of the food giant
corporations
 REVIEW
• What is rennet and how is it used in
cheesemaking?
• Cheese is an unprocessed food. True or false?
• What is the difference between cheese and
processed cheese?

Floris van Schooten, Still Life with Bread and Cheese, c. 1655
FOOD AND FERMENTATION
Part 2

José Escofet,
Table of Bread,
Cheese, Olives,
and Wine, 1992

SC/NATS1560 3.0 UNDERSTANDING FOOD

 LEARNING OBJECTIVES
• To describe alcoholic fermentation, define “wild yeasts”,
and name the microorganism most commonly used for
alcoholic fermentation
• To describe the most common
drinks and foods produced by
alcoholic fermentation, their
raw ingredients, and their
processing
– Wine
– Beer
– Bread
 ALCOHOLIC FERMENTATION
• Alcoholic fermentation: yeasts convert sugars into
ethyl alcohol and carbon dioxide
• Ethyl alcohol, or ethanol (“drinking alcohol”)
− psychoactive substance, narcotic
− in moderate amounts, it causes mild inebriation
− in larger amounts, intoxication and addiction
− antiseptic, it kills harmful microbes
• “wild yeasts”, or natural starters
• Saccharomyces cerevisiae
 WINE
• Made mostly from grapes of Vitis Vinification (wine-making):
vinifera • grapes are crushed into must
• over 1300 varieties • wild yeasts or inoculated
− e.g., cabernet sauvignon, merlot, Saccharomyces cerevisiae convert
pinot noir, syrah, grenache, sugars into CO2, ethanol, and
sangiovese, chardonnay, riesling, aromatic molecules
sauvignon blanc, sémillon, chenin • skins are steeped in to give colour
blanc, pinot grigio, etc. and stronger flavours
• Terroir: place of origin, gives • wine is racked to eliminate the dregs
distinctive character to the wine (dead yeasts and skins), filtered, and
• Alcohol content: 8%-14% ABV fined
• Wines are made also from other fruit, • wine is aged
e.g. cherries, dates, apples (cider), − if in oak casks, contact with wood
pears (perry) adds complexity to the flavour
− finest wines, up to 30-40 years
 REVIEW
• What is the most used
microorganism for
alcoholic
fermentation?

• What contributes to the

distinctive character of a
wine?

© Toby Bridson
 BEER
• From grains: barley, wheat, oats, rice, corn
• grains are turned into malt by sprouting,
then kilned and ground
• amylase enzymes convert starch into sugars
• hops added to the wort for flavour
• yeast convert sugars into CO2+alcohol
• alcohol content, 4-5% (up to 10%)
• ale: warm brewing (21-25 °C), top
fermentation with Saccharomyces
cerevisiae
• lager: bottom fermentation (6-8 °C), cold
brewing with Saccharomyces uvarum
Kilning
Malting Adding hops Adding Conditioning:
and Mashing
the grains and boiling yeast and re-fermenting,
grounding the malt
the wort fermenting fining, and
the malt
centrifuging
 REVIEW
• What is malt and how is it used in beer brewing?
• What are the main differences between wine
making and beer brewing?

• How is lager different

from ale?
 BREAD
• Flour: milled grains • sourdough bread uses a
• hard wheat: high protein starter containing “wild
content (glutenin, gliadin) yeasts” (yeasts and lactic acid
• amylase breaks down some of bacteria)
the starch into sugars • baking completes and then
• flour+water=dough stops the fermentation
• glutenin+gliadin (in water) • surface water evaporation
=gluten and Maillard reactions form
crust and crumb
• kneading allows gluten to
form an elastic mass
• leavening by fermentation:
− yeast (wild or Saccharomyces
cerevisiae) turns sugars into
CO2 and alcohol
− gas bubbles make dough rise
• heat solidifies stretched dough
 UNFERMENTED BREADS
• Unleavened flatbreads:
matzo or matzah, lavash,
rotis, chapatis, tortillas
(from corn flour), and
others

• Quickbreads: leavened by CO2-

producing chemical reactions
without fermentation
− e.g., cakes, scones, cookies,
pastries, biscuits, etc.
− chemical leaveners: baking powder,
baking soda, ammonia salts
 REVIEW
• Give an example of each of the two main
kinds of fermentation
• What is the difference between sourdough
bread and non-sourdough bread?
 Jean-François Millet, Des Glaneuses, 1857

WHERE FOOD COMES FROM

PART 1
NATS1560 UNDERSTANDING FOOD
For class use only. Do not circulate. 1
 LEARNING OBJECTIVES
• To define arable land and fertility, and identify the main
components of soil and the factors that determine soil
fertility
• To identify the main parts of the hydrologic cycle
• To discuss in broad lines the historical process of
industrialization of agriculture
• To discuss the mechanization of agriculture and its
effects
• To discuss the main parts of the nitrogen cycle and the
role of bacteria in fertility and plant nutrition
• To discuss two main aspects of the chemical revolution
in agriculture, the synthesis of ammonia and synthetic
fertilizers
For class use only. Do not circulate. 2
 KEY IDEAS
• Since the Neolithic Revolution 12000 years ago, our
food comes mostly from agriculture
• Many technological innovations in irrigation, farming
equipment, and plant and animal breeding have
expanded human farming capabilities
• In the last two centuries, agriculture has been
increasingly industrialized: machinery, fertilizers,
pesticides, fossil fuels, monocultures, factory farming
• Industrialization has greatly increased the productivity
of agriculture but it also entails great environmental,
social, and nutritional costs
• The current industrial food system is unsustainable

For class use only. Do not circulate. 3

 WHAT IS SUSTAINABILITY?
• Sustainability is the ability to
satisfy our present needs without
compromising the ability of
future generations to satisfy their
needs
• It is a holistic ideal that unites
- environmental sustainability
- economic sustainability
- social sustainability
• Sustainability is achieved by living
within the limits of available natural
and human resources so as to
permit to all living systems
(including humans) to prosper
perpetually.
UN Sustainable Development Goals for 2030

For class use only. Do not circulate. 4

 SOIL
• Soil has a complex structure and varies

biological activity
litter
from place to place topsoil: humus,
sand, silt
• Soil = 45% mineral component, 5% subsoil: clay and
organic component, 25% water, 25% air mineral deposits

• Soil derives from rock weathering and

rock weathering
partly weathered
biological activity rock

• Organic layer: litter, humus, worms, bedrock

insects, and millions microorganisms
• Rock weathering: breaking down into
fragments and particles over centuries
• particle size: sand, silt, clay
– smaller particles, lower permeability
• Loam: sand-silt-clay mixture in proportions
suitable for fertility
• Soil is a non-renewable resource
5
For class use only. Do not circulate.
 ARABLE LAND AND FERTILITY
Source: Environment
Canada 1982, Lands • Arable land: land fit for
Directorate
agriculture
• 5% of Canadian land is arable
• Urban sprawl in Southern
Ontario is subtracting prime
arable land from agriculture
• Plants draw nourishment from
soil, water, and air, and energy
from sunlight
• Land fertility (i.e., capacity to sustain plant
growth) depends on soil, water, and climate
• Agriculture and other human activities cause
loss of soil fertility, soil erosion, compaction,
and salinization
For class use only. Do not circulate. 6
 REVIEW
• What is soil composed of?
• How is soil formed?
• What is loam?

• What is arable land?

• On what does land fertility
depend?
© Toby Bridson

For class use only. Do not circulate. 7

 THE HYDROLOGIC CYCLE
• Natural cycle of precipitation, runoff, evaporation
• 2.5% of Earth’s water is fresh water, ¾ of which locked in ice
• Earth’s fresh water supply is in principle sufficient to sustain
the world’s population
• Poor water
management:
wasteful irrigation,
pollution,
deforestation, climate
change
• > 2 billion people are
affected by water
scarcity
• ¼ people to suffer
from water shortages
by 2050
For class use only. Do not circulate. 8
 THE MECHANIZATION OF AGRICULTURE
• Industrial Age: first steam
engines and then gas
engines replaced animal
labour
• Today: diesel tractors can
pull multiple steel ploughs
• Excessive tilling (plowing
and harrowing) causes soil
erosion and water runoff

• First plows were just sticks used

to prepare the soil for sowing
• Heavy ploughs and wheeled
ploughs pulled by oxen and
horses expanded the arable land
in various regions of the globe
For class use only. Do not circulate. 9
THE MECHANIZATION OF AGRICULTURE

• Grain harvesting and

threshing used to be very
labour intensive
• Today, farmers use
harvesters and combines
• Fossil fuels, capitalization,
workers’ displacement
For class use only. Do not circulate. 10
 THE NITROGEN CYCLE
• 78% of atmosphere in volume is nitrogen gas, N2
• Plants cannot absorb and use nitrogen from air
• Nitrogen fixation: conversion of atmospheric N2 into
nitrogen compounds that plants can absorb and use
• Soil and root
microorganisms allow
a natural nitrogen
cycle
− decomposing
microbes in soil
− nitrogen-fixing
bacteria in roots and
soil
− e.g. Rhizobium
bacteria in legume
Source: Lumen Learning roots
11
For class use only. Do not circulate.
 REVIEW
• Why plants cannot use nitrogen from air?
• What is nitrogen fixation?

For class use only. Do not circulate. 12

 FERTILITY AND PLANT NUTRITION
• Growing crops exhausts the
fertility of the land by depleting
the soil of plant nutrients
• Farmers used to restore fertility
by
− fertilizing fields with animal
manure and green manure
− practicing crop rotation
− two-field rotation: alternating crop
growing and idling (fallow field)
− three-field rotations: alternating
grains, legumes, and idling

For class use only. Do not circulate. 13

 THE CHEMICAL REVOLUTION
IN AGRICULTURE: FERTILIZERS
• Justus Von Liebig (1803-1873), one of
the founders of organic chemistry and
plant and animal physiology

• produced the first

synthetic fertilizer
• popularized the N-P-K
model of plant nutrition:
− nitrogen (N)
− phosphorous (P)
− potassium (K)
For class use only. Do not circulate. 14
For class use only. Do not circulate. 15
 NATURAL NITRATE SOURCES
• In late 1800s, European industrial powers
and USA had become dependent on N-P-K
fertilization to feed their growing
population
• Natural sources of nitrates, guano and
saltpeter (sodium nitrate and potassium
nitrate), were mined unsustainably
• They were projected to run out by 1930
Chinese workers in a guano mine
in the Chincha Islands, Peru,
1865, americanhistory.si.edu

• Urgently felt need to

produce nitrogen-based
fertilizers artificially
One of many abandoned saltpeter mines in Northern Chile.
© Diego Delso via Wikimedia Commons
For class use only. Do not circulate. 16
 THE SYNTHESIS OF AMMONIA:
THE HABER-BOSCH PROCESS
•Nitrogen-based fertilizers could start to be
industrially produced thanks to a process
invented by the German chemists Fritz Haber
and Carl Bosch in 1908-1913
•The synthesis of ammonia from its elements,
nitrogen (from the atmosphere) and
hydrogen (from water and other sources)
BASF Oppau Works, the first
ammonia factory, opened in 1913

Haber’s experimental apparatus

•Huge productivity increase of agriculture in the 20th century was due in large
measure to the Haber-Bosch process. About half of the world population
today is fed thanks to this process
•But synthetic fertilization also causes nitrogen and phosphorus run-off and
eutrophication, biodiversity loss, and large huge fossil-fuel consumption
•Synthetic ammonia is also used for mass-production of explosives 17
 REVIEW
• What is the “chemical revolution” in agriculture?
• Who was Justus von Liebig, and what role did he
play in the development of agriculture?
• What is the Haber-Bosch
process, and what role does it
play in modern agriculture?

© Toby Bridson

For class use only. Do not circulate. 18

 Jean-François Millet, Des Glaneuses, 1857

WHERE FOOD
COMES FROM
Part 2

NATS1560 UNDERSTANDING FOOD

For class use only. Do not circulate. 1
 OUTLINE
• To discuss some of the main features of
industrial agriculture
− pesticides
− crop selection and monoculture
− horizontal and vertical integration
• To discuss the hidden costs and the nutritional
price of industrial agriculture

For class use only. Do not circulate. 2

 THE CHEMICAL REVOLUTION
IN AGRICULTURE: PESTICIDES
• Insecticides
– plant extracts: pyrethrum, rotenone, nicotine sulphate
– synthetic compounds: organochlorine compounds (e.g. DDT),
organophosphates, carbamates
– new nicotine-like insecticides, aka neonicotenoids

• Fungicides
• Herbicides
– 2,4-D (2,4 dichlorophenoxyacetic acid)
– atrazine
– glyphosate (©Roundup)
• Rodenticides
For class use only. Do not circulate. 3
 THE CASE OF DDT
(dichloro-diphenyl-trichloroethane)

DDT hazards for humans: breast and

other cancers, nervous system and
liver damage, developmental delay,
miscarriages, infertility 4
For class use only. Do not circulate.
For class use only. Do not circulate. 5
 REVIEW
• What are the main
kinds of pesticides?

• What is DDT?
• What is Silent Spring?

For class use only. Do not circulate. 6

 MONOCULTURE
AND FACTORY FARMING
• From subsistence farming to • Factory farming: intensive
agribusiness livestock production
• From mixed farming to − cattle, pigs, poultry, fish
monoculture − for meat, milk, eggs
• Selection of a few, high-yield cash • maximization of production at the
crops cost of the welfare of animals and
• In Canada, mainly maize, ecosystems
soybeans, wheat, and canola • confinement, overcrowding, and
other forms of mistreatment of
animals
Intensive livestock • routine use of growth hormones,
farming generates 14.5% growth and pre-emptive
of global greenhouse-gas antibiotics
emissions. • noxious smells, waste, and
greenhouse gases (carbon
dioxide, methane, and nitrous
oxide)
For class use only. Do not circulate. 7
 INDUSTRIAL FARMING
• Mechanization +
• hybrid seeds +
• irrigation +
• synthetic
fertilizers +
• pesticides
=
• high-yield
monocultures
Source: G. D. Stone, fieldquestions.com
For class use only. Do not circulate. 8
THE RESULTS OF THE INDUSTRIALIZATION
OF AGRICULTURE

For class use only. Do not circulate. 9

DECLINE OF NUTRITIONAL VALUES

• Industrial agriculture
enhances quantity
• but at the expense of
quality
• due to soil depletion
• use of artificial
fertilizers
• and a small number
of high-yield varieties
For class use only. Do not circulate. 10
 THE PRICE OF INDUSTRIAL FARMING
• High input
– technology
– fossil fuel
• Oligopoly
– horizontal integration
– vertical integration
• Labor issues and social impact
• Loss of biodiversity
• Pollution
• Decline of nutritional values
For class use only. Do not circulate. 11
 EXERCISE
• Q: What is an oligopoly?
• A: A market system in which there is a small number of
producers or sellers
• Q: How does an oligopoly form?
• A: by integration of industries
• Q: What is horizontal integration?
• A: When a company buys out, merges with, or drives out
of the market competitors to get control a larger share
of the market in one segment of a supply chain
• Q: What is vertical integration?
• A: When a single company acquires control of several
segments of a supply chain
• Q: Can you give an example?
For class use only. Do not circulate. 12
EXAMPLE OF CANADIAN INTEGRATION

For class use only. Do not circulate. 13

 REVIEW
• What is the overall result of industrial
agriculture?
a. Reduced dependence on fossil fuels
b. High yield in a small number of crops
c. Better nutritional quality of crops
d. Greater variety of crops

For class use only. Do not circulate. 14

INDUSTRIALIZATION OF FOOD

PART 1
NATS1560 UNDERSTANDING FOOD
For class use only. Do not circulate. 1
 LEARNING OBJECTIVES
• To explain the function of food processing in human food systems,
and of the role of the food processing industry in the economy and
public health today
• To highlight the inadequacy of the distinction between “natural”
and “processed” foods and replace it with the more useful
distinction between degrees and types of processing
• To define industrial food, and compare and contrast it to artisanal
food
• To define the types and functions of food additives in industrial
foods, and identify a few examples
• To define food fortification and enrichment, and identify a few
example
• To discuss the problem of added sugars in industrial foods
• To define horizontal and vertical integration in the food industry
• To describe the extent, character, benefits and costs of the global
industrialized food system
For class use only. Do not circulate. 2
 KEY IDEAS
• Huge growth of the food processing industry in
the last two centuries
• The food processing industry is now a major
driver of economy
• Integration of food industries, global oligopoly
• Industrial food vs. artisanal food
• Industrially processed foods and drinks are
major drivers of the global obesity epidemics
• The “eat more” environment: low-cost, high-
calorie, aggressively marketed, ubiquitous,
hyper-convenient snacks and soft drinks
For class use only. Do not circulate. 3
 EXERCISE
• Q: What is an oligopoly?
• A: A market system in which there is a small number of
producers or sellers
• Q: How does an oligopoly form?
• A: by integration of industries
• Q: What is horizontal integration?
• A: When a company buys out, merges with, or drives out
of the market competitors to get control a larger share
of the market in one segment of a supply chain
• Q: What is vertical integration?
• A: When a single company acquires control of several
segments of a supply chain
• Q: Can you give an example?
For class use only. Do not circulate. 4
EXAMPLE OF CANADIAN INTEGRATION

For class use only. Do not circulate. 5

 NEW CANADA’S FOOD GUIDE
• Issued by Health
Canada in Jan 2019
• Last of a series of
started in 1942
• Education tool based
on the best available
scientific evidence
• It translates nutrition
science into practical
advice for all
Canadians

For class use only. Do not circulate. 6

Limit highly processed foods.
… But almost all of the
Processed food is unhealthy, food we eat is processed
natural food is healthy! in one way or another…

What is
“natural
food”,
anyway?

7
For class use only. Do not circulate.
NATURAL FOOD AND PROCESSED FOOD
• Every food originates from nature, hence natural
• Practically all food is processed in some ways
• “Natural” is often used as a merchandising claim
• There is no hard-line distinction between natural
and processed foods
• but there are differences in degrees and kinds of
processing
• Canadian labelling regulations allow
representing a food or ingredient as
“natural” if it has not been “submitted
to processes that have significantly
altered their original physical,
chemical or biological state”
– “minimum processes” vs “maximum processes”

For class use only. Do not circulate. 8

 DEGREES OF PROCESSING
• Most foods can roughly be place somewhere on a
continuum spectrum from “unprocessed” to “highly
processed”:
1. Little or no processing: freshly picked fruits and
vegetables, raw milk, freshly cut meat and fish, etc.
2. Some processing: washed, packaged, artificially ripened,
pre-cut fruits and vegetables, homogenized and
pasteurized milk and cream, filtered fruit juices, frozen
and canned foods, etc.
3. More processing: sausages, patties, and cured meats,
smoked fish, cheese, yogurt, sour cream, etc.
4. Highly processed (several stages of processing, many
ingredients, additives): baked goods, crackers, candies,
boxed cereals, processed cheese, pops, sauces, etc.
For class use only. Do not circulate. 9
ARTISANAL FOOD VS. INDUSTRIAL FOOD
• Another way of distinguishing food quality is by kind of
processing: artisanal processing vs industrial processing

• Artisanal = made by • Industrial = mass-produced

hand or craft methods by industrial methods

For class use only. Do not circulate. 10

 INDUSTRIAL FOOD PROCESSING
• Process optimized for mass production, efficiency, and
uniformity, minimizing raw materials and labour costs
• Use of industrial machinery and chemical substances
• Industrialization aims to raise the profit margin for
manufacturers while also lowering the store price of products
• “Added value” generated by industrial processing:
preservation, convenience, novelty, consumer appeal through
the engineering of cravings and advertising
• Small share of the store price goes to the farmers
– e.g., eggs and milk, 60%; bread, < 6%; cereal, 1%
• Industrial food processing entails hidden costs
– fossil fuel energy per kcal of food produced, 10:1
– waste, pollution, and environmental damage
– health issues for consumers
– deskilling and loss of knowledge of workers and consumers
For class use only. Do not circulate. 11
 REVIEW
• A food is either natural or processed, it
cannot be both. True or false?
• Most foods are processed in some way
and to some degree. True or false?

• Using the description in “Modern Production, Distribution,

and Sales” in the textbook, give one example of food for
each of the four groups
1. Little or no processing
2. Some processing and more processing
3. Highly processed

© Toby Bridson

For class use only. Do not circulate. 12

 FOOD ADDITIVES
• Health Canada definition of food additives*:
A food additive is any chemical substance that is added to food during
preparation or storage and either becomes a part of the food or affects its
characteristics for the purpose of achieving a particular technical effect.

• Food additives include • They do not include

– preservatives − food ingredients such as salt,
– emulsifiers, thickeners, stabilizers sugar, starch
– non-sugar sweeteners − vitamins, minerals, amino acids
– colours − spices, seasonings, flavouring
preparations
– antifoaming agents, anticaking
agents, anti-sticking agent − agricultural chemicals
– glazing and polishing agents, − veterinary drugs
– and others − food packaging materials

*“Food Additives”, Health Canada Food and Nutrition, www.canada.ca/en/health-canada/services/food-nutrition/food-safety/food-

additives.html#a1
For class use only. Do not circulate. 13
 FOOD ADDITIVES: PRESERVATIVES
• Chemicals that prevent spoilage
– antimicrobial and antifungal agents, antioxidants
– used to lengthen the shelf-life of commercial food
• Common examples:
– sodium nitrate and sodium nitrite
– sulphites and sulphur dioxide
– sorbic acid and its salts, sodium sorbate, potassium
sorbate, calcium sorbate
– BHA and BHT
– ascorbic acid
– citric acid
– disodium EDTA
For class use only. Do not circulate. 14
FOOD ADDITIVES: OTHER STUFF
• Colours
– plant extracts: annatto, turmeric
– synthetic dyes (coal-tar
derivates): yellow tartrazine,
orange B, citrus red 2, etc.
• Emulsifiers
– lecithin (phospholipid)
– mono- and diglycerides, DATEM
(diacetyl tartaric acid ester of
mono- and diglycerides), PGEs
(polyglycerol esters of fatty acids)
• Thickeners
– agar-agar, carrageenan
– pectin, gelatin, gums
For class use only. Do not circulate. 15
 FLAVOUR ENHANCERS
• Non–sugar sweeteners (classified as food additives by
Canadian Food and Drug Regulations)
̶ e.g., saccharin, sorbitol, aspartame, cyclamate,
acesulfame-K, and others
• “Flavouring preparations” are not classified as food
additives by Canadian Food and Drugs Regulations
• “Natural flavours”: compounds extracted from plants,
animals, yeast, or algae that imitate certain food
flavours
− e.g., monosodium glutamate (MSG), hydrolyzed
vegetable proteins, yeast extract, castoreum, etc.
• “Synthetic flavours” or “artificial flavours”: synthetic
compounds that imitate natural flavours
− e.g., vanillin, diacetyl and acetoin (butter-like flavour)
For class use only. Do not circulate. 16
 REVIEW
• What are the main categories of
food additives?
• What are some specific examples of
food additives in each category?

• What is the difference between natural and

artificial flavours?
• What is an example of natural flavour?
• What is an example of artificial flavour?

© Toby Bridson

For class use only. Do not circulate. 17

INDUSTRIALIZATION OF FOOD

PART 2
NATS1560 UNDERSTANDING FOOD
For class use only. Do not circulate. 1
 FORTIFICATION AND ENRICHMENT
• Fortification: addition of micronutrients or fibre to
commercial foods
– enrichment: fortification aimed to restore micronutrients
that were lost during processing
• mandatory for certain foods, as a public health intervention to
prevent nutritional deficiencies
• permitted for other foods, voluntarily used by food
manufacturers as a marketing strategy
• mandatory in Canada:
– milk and milk products: vitamin D
– skim milk: also vitamin A
– evaporated milk: also vitamin C
– white flour and white-flour
products: thiamine, riboflavin,
niacin, folic acid, iron
– table salt: iodine
For class use only. Do not circulate. 2
 REVIEW
• How does enrichment • Which of the following is
differ from fortification? an example of
fortification?
a. Calcium added to
orange juice
b. Mono- and diglycerides
added to bread
c. Sorbitol added to a
protein bar
© Toby Bridson d. Citrus red 2 added to
fruit juice

For class use only. Do not circulate. 3

THE FOOD PROCESSING INDUSTRY
• The industry that “chemically, mechanically or
physically transforms materials and
substances into new products.”
• Second-largest manufacturing industry in
Canada, largest manufacturing employer
• Since the 1950s, large-scale integration,
domestically and internationally, has led to a
worldwide oligopoly

For class use only. Do not circulate. 4

 AN EXAMPLE OF FOOD
INDUSTRY INTEGRATION
• 1850-1890, Christie, Brown &
Co, Toronto becomes largest
cookies manufacturer in
Canada
• 1928, US National Biscuit
Company (later, Nabisco) buys
Christie, Brown & Co
• 2011, Nabisco merges with
Kraft Foods International
• 2015, Kraft merges with Heinz
to form Kraft Heinz
For class use only. Do not circulate. 5
BIG FOOD OLIGOPOLY

For class use only. Do not circulate. 6

 WATER AND SOFT DRINKS
• Non-distilled water contains traces of minerals
• Despite marketing claims, bottled water is not purer,
safer, or healthier than tap water
• Carbonation: addition of carbon dioxide gas
• Carbonation process invented by Joseph Priestley in
1772, to simulate fizzy spa waters
• Commercialized by Jacob Schweppe in 1800s

• Addition of flavours and sugar, e.g. quinine and tonic

water
• American soda fountains: water, syrups, sugar, and
carbonation
• Cola drinks with kola seeds (caffeine, theobromine,
kolanine)
• 1886, Coca Cola: cola from kola, coca from cocaine
• “Fruit drinks” (coolers, etc.): less than 25% fruit juice
For class use only. Do not circulate. 7
For class use only. Do not circulate. 8
 ADDED SUGARS
• Sugar, in various forms, is
added to 74% of packaged
drinks and foods
• Pops and sport drinks are a
major source of added sugars
• Many different names for sugar are used on food
labels, e.g. malt syrup, molasses, dextrose, etc.
• High fructose corn syrup, or HFCS, called glucose-
fructose or glucose-fructose/sugar on Canadian
labels
– made by processing corn starch with enzymes
– sweeter than glucose, cheaper than other sugars
For class use only. Do not circulate. 9
Source: Canadian Sugar Institute, Consumption of Sugars in Canada, sugar.ca/Sugars-Consumption-and-
Dietary-Guidelines/Consumption-of-Sugars-in-Canada.aspx

For class use only. Do not circulate. 10

 REVIEW
• What percentage of the • Why did Joseph Priestley
daily intake of free sugars invent carbonated water?
conditionally a. To commercialize it and
recommended by WHO is make a profit
approximately contained b. To replace beer
in one can of Coca Cola?
c. To improve on kola
a. 50% water
b. 100%
d. To reproduce the
c. 150% healthy virtues of
d. 200% natural fizzy waters

For class use only. Do not circulate. 11

MODERN DISTRIBUTION AND SALE
• From local, seasonal production and sale
to a global food system
• From specialist retailers (butcher, baker,
greengrocer, fishmonger, confectioners,
etc.) to supermarkets and superstores
• Selling mindless consumption, glut,
speed, and convenience: packaged
foods, prepared foods, convenience
foods, fast food
• Sly and manipulative marketing
• Overpackaging and non-biodegradable
packaging
• Excessive and avoidable food waste
For class use only. Do not circulate. 12
 FOOD AND SUSTAINABILITY
• Until now, economic development
has prioritized quantity over
quality and disregarded the harm
made to human health and the
environment
- deforestation and destruction of
ecosystems
- loss of biodiversity
- loss of fertile soil
The second goal of
- water and air pollution the UN 2030 Agenda for Sustainable
- climate change Development is to end hunger and promote
sustainable agriculture!

• Sustainability is the ability to meet the needs of the present

without compromising the ability of future generations to meet
their needs
• We now know that the present food system is unsustainable
• A transition to a sustainable global food system is needed
 REVIEW
• What has not been a feature of • The present food system is
the industrialization of the food
system in the last 100 years? a. sustainable
b. unsustainable
a. The ability to produce enough
c. the best that we can expect
food for the growing to have
population
b.An increase of the number and d. able to meet human needs
variety of specialist food now and in the future
retailers
c. A decrease of the ability of
small-scale producers and
manufactures to compete on
the market
d.An increase of food loss and
waste