Dr.
Dharmalingam K
B.Tech., M.Tech., DIS, PhD.
Food Biotechnology
Assistant Professor
Department of Biotechnology
Chaitanya Bharathi Institute of
Unit - 1
Technology
Hyderabad – 500075
Google
scholar: https://scholar.google.com/citations?user=n
9E-c2wAAAAJ&hl=en
Publons: https://publons.com/researcher/3797989/k
-dharmalingam/
ORCiD: https://orcid.org/my-orcid?orcid=0000-0002-
6267-1657
Course Objectives:
1. Student is made to understand the importance of food biotechnology and its
nutritive value.
2. Students are taught the types of food available in the nature and its consumption
value.
3. Students made to understand the food spoilage.
4. Students are enlightened about the importance of food processing.
5. Students are made aware of chemical and physical methods of food processing.
Course Outcomes:
1. Apply the fundamentals of food biotechnology to their real-life situation
2. Differentiate types of food and explain their nutritive value
3. Examine the types of pathogens and their effect on food
4. Demonstrate the physical and chemical methods of food processing.
5. Apply the techniques to preserve the food material to avoid food spoilage.
UNIT-I
Introduction To Food Biotechnology: Introduction to scope and importance of food
biotechnology, Nutritive value of the food; Shelf life of food. Water relationships in foods:
water activity and its relevance to deteriorative processes in foods (chemical, enzymic,
physical and microbial changes). Lipids of biological importance like cholesterol and
phospholipids. Food Pigments & Flavoring Agents: Importance, types and sources
UNIT- II
Food Products: Introduction to Probiotics, Nutraceuticals and GM foods; Processing and
post-harvest technology of various food products (High Fructose Corn syrup, Single Cell
Protein and Bakery Products, Milk Products). Fermented food: origin, scope and
development, saurkraut, youghurt, cheese, miso, tempeh.
UNIT- III
Food Spoilage And Food Microbiology: Shelf life of food. Microbes found in raw materials
and foods that are detrimental to quality, Factors that influence the development of
microbes in food, Food spoilage by bacterial agents (Clostridium, Salmonella, Vibrio and
Shigella), Non-bacterial agents (Protozoa, Algae, Fungi and Viruses)
UNIT- IV
Food Processing Applications: Principles and methods of food processing (freezing, heating,
dehydration, canning, additives, fermentation, irradiation, extrusion cooking, dielectric
heating). Enzymes and chemicals used in food processing for flavor development; Processing
of meat, fisheries, vegetables, and dairy products. Food adulteration and food safety.
UNIT- V
Food Preservation: Application of sugar and salt, antimicrobial agents, biological agents, non-
ionizing and ionizing radiations in preservation of foods. Basic concepts in thermal
destruction of microorganisms D, Z, F values. Blanching, Pasteurization and Sterilization of
foods. Controlled and Modified atmosphere storage of foods. Intelligent packaging concept.
UNIT-I
Introduction To Food Biotechnology
Food Biotechnology (FBT)
Food biotechnology is an umbrella term covering a vast variety of processes for using
living organisms such as plants, animals, microbes, or any part of these organisms to
develop new or improved food products.
FBT – Goal
➢ To provide a more abundant, less expensive, and a more nutritious food supply in
order to address the needs of our growing global population
➢ Use of biotech plants can produce more food on less land, by reducing the amount of
crops lost to disease and pests. It can reduce CO2 emissions from the farming process,
the amount of pesticides used to produce foods, and in the future, the amount of
water needed to grow crops. Benefits for the environment, the consumer and the
farmer.
FBT – Existence
➢ Food biotechnology is not new.
➢ For thousands of years people have been discovering that fruit juices ferment into wine,
that milk can be used to develop products such as cheese or yogurt, or that beer can be
made through the fermentation of malt and hops
➢ FBT – Techniques
➢ FBT techniques are often divided into old and new
➢ Older FBT techniques include conventional crossbreeding, which refers to the random
recombination of genes through sexual reproduction leading to a new organism with
improved traits - improved crop yield, aesthetic qualities, increased tolerance to physical
stress such as cold temperatures, and increased resistance to disease and insects.
Disadvantage of old FBT: Crossbred plants, for instance, may require several
generations to achieve a particular trait due to the randomness of gene transfer
Modern FBT
✓ It includes the joining of two pieces of DNA from different organisms leading to a
single piece of DNA.
✓ Individual “specific” genes are transferred from one organism to another in order to
improve the nutrient levels of a food, for example, such as fortifying a fruit or
vegetable.
✓ Modern techniques are much faster and more precise. It is possible to quickly
transfer a specific gene of interest rather than waiting on the random shuffling of
genes over several generations.
Food products developed by FBT
➢ Corn varieties containing a bacterial gene that kills insects and soybeans inserted
with gene that renders them resistant to weedkillers
➢ Cotton, squash, and papaya are other examples of commodities in which
biotechnology was used to reduce pesticide use, increase profitability through
greater yield
➢ Examples of foods developed through biotechnology to increase the levels of
nutrients or to address a health concern include oils, such as canola, in which the
levels of nutritionally essential fatty acids are increased, varieties of wheat that
do not contain gluten, and potatoes (protein), kiwi (resveratrol), and lettuce
(iron)
Some of the important genera known to occur in foods are
Some are desirable in certain foods; others bring about spoilage or cause gastroenteritis
Scope of FBT
▪ FBT is a food processing technologies which improve food quality, nutritive value,
enhance the food safety, wholesomeness & proper food supply.
▪ The manufacturing methods are done through processing, preservation and different
way of packaging technologies.
▪ Food scientists do research to bring better nutrition for health benefits and shelf life of
the product.
▪ It is a study on characteristics of food, its nutritional composition, chemical and
physical reactions that change take place while processing and storage.
▪ Food scientists are responsible to follow the rules and regulations of government
associates’ like HACCP AND FSSAI which involved the safety and regulatory aspects
Scope of FBT
Importance of FBT
Food biotechnology is an important and promising research field that applies biotechnology
to the production, processing and manufacture of foodstuffs. FBT has helped to improve
food quality, quantity and processing.
1) Improving the quality and yield of agricultural products through genetic engineering
and cell engineering.
2) Producing “green” antioxidants and preservatives, etc., for the preservation of
agricultural products through genetic engineering and fermentation.
3) Improving the added value of food and the utilization of agricultural products and the
health function of food, and making the food processing effective through genetic
engineering, fermentation, enzyme engineering, protein engineering and molecular
evolution engineering.
4) Reducing food losses, improving the efficiency of food quality management and ensuring
food quality and safety through genetic engineering, enzyme engineering
and fermentation.
5) Improving the resource utilization rate, and reducing the environmental pollution by
treating food processing wastes through fermentation and enzymatic engineering.
Yu P (2017) Food Biotechnology-An Important and Promising Research Field. J Food Biotechnol Res. Vol. 1 No. 1:1
Nutritive value of the food
What is the nutritional value of food?
• Typical nutrients mentioned in a nutritional value are proteins, carbohydrates, fats,
vitamins and minerals.
• Nutritional value or nutritive value as part of food quality is the measure of a well-
balanced ratio of the essential nutrients carbohydrates, fat, protein, minerals, and
vitamins in items of food or diet concerning the nutrient requirements of their
consumer.
• Nutritional value should be labeled on food products.
• The nutritional value of foods tells you how much energy the food contains as well
as which nutritional molecules are present in the food and how much.
What is calorific value?
Calorific value is an important parameter to measure the energy content of food
1. Calorific value refers to the amount of heat liberated from the complete combustion
of 1 g of food or fuel in a bomb calorimeter.
2. Calorific value is the amount of energy available from an item of food when digested,
mostly from carbohydrates and fats.
3. It helps us to know the amount of energy required to carry out day to day activities.
4. The highest calorific value is also known as gross energy or gross calorific value.
5. The gross calorific value of fats is 9.45 kcal/g, for carbohydrates, it is 4.1 kcal/g and
for proteins, it is 5.65 kcal/g.
Energy content: The energy content can be determined using a simple calculation.
We know which groups of molecules contribute to the energy content of a food.
The three most relevant groups when discussing food chemistry basics: carbohydrates,
fats and proteins.
Molecules Mass (g) Energy content of Energy in product
molecules (kcal/g) (kcal)
Fats 5 9.45 47.25
Proteins 8 5.65 45.2
Carbohydrates 3 4.1 12.3
Total 105
Source :https://foodcrumbles.com/determining-the-nutritional-value-of-food-products/
Determining fat, carbohydrate & protein content
There are two ways to determine these quantities:
1. The analytical route
(Nitrogen by the Kjeldahl method, Carbohydrate by phenol-sulfuric acid method, TAG by GC)
2. The literature route
(The USDA has a very extensive database. It contains the nutritional value of a lot of different
products, both processed and unprocessed foods)
Workout to burn the calories present in your
Favorite Junk Food
Shelf life of foods
Shelf-life is the length of time a food can be
kept under stated storage conditions while
maintaining its optimum safety and quality.
Shelf life of a food begins from the time the What is shelf life?
food is manufactured
It is dependent on many factors such as its
manufacturing process, type of packaging,
storage conditions and ingredients.
A best-before date reflects the length of time a food can
reasonably be expected to retain its best quality e.g.
flavour.
Examples of foods which have best before dates
include canned, dried and frozen foods.
A use-by-date date is the length of time a food can
How is shelf-life reasonably be expected to be safe to consume when stored
indicated on foods? under stated storage conditions.
Consequently, these foods may present a risk of food
poisoning if consumed after the use-by date.
Examples of foods which have use-by-dates include
chilled dairy products, cooked meats and prepared salads.
Majumdar et al. (2018). Microbial contamination and food degradation
How is shelf-life determined?
It is the responsibility of food This includes the storage conditions required
manufacturers to determine the shelf-life to achieve that shelf-life, e.g. ‘keep
and to label their products accordingly. refrigerated once opened’.
Initially, the manufacturer determines the
Shelf-life is typically determined during the
characteristics (intrinsic and extrinsic) of the
development of a food.
food which affect its safety and/or quality.
These characteristics include the ingredients
Where necessary, the manufacturer may also
used, manufacturing process, type of
conduct other studies such as microbiological
packaging, e.g. vacuum packing or modified
sampling and analysis
atmosphere
Methodologies to determine foods’ shelf life
Direct method
• It is a real-time study - storing the product under conditions similar to those that it will
actually face, to monitor its evolution in regular intervals of time.
• The main advantage of this method is that it creates a very accurate estimation of the
time it takes for a product to deteriorate
• However, they are studies that usually take a long time and do not consider the fact
that storage conditions of a product are not always stable over time.
Challenge Test
✓ Introducing pathogens or microorganisms into the food during the production process,
so that the product is exposed to the real conditions it will suffer in real life.
✓ The main disadvantage of this type of test is that the effects caused by the studied
parameters are the only things analysed, and the fact that the product can be faced
with multiple factors at the same time is not addressed
Methodologies to determine foods’ shelf life
Predictive microbiology
• Different microbial responses of foods to varying environmental conditions, based on mathematical and statistical
models will be done
• Widely used when developing a new product, does consider the possible changing conditions of a product
• However, it implies greater complexity and that the results correspond to a simulation, which may not be accurate.
Accelerate shelf life tests
✓ Conditions such as temperature, oxygen pressure or moisture content are modified to accelerate spoilage reactions
of a food.
✓ These predictions allow one to predict the behaviour of foods in certain conditions
✓ These studies are very versatile, low cost for the manufacturer and allow for the comparison of different scenarios.
Obviously, since it is not an exact representation of reality, there is some margin of error in the obtained results.
Survival method
➢ It is based on the opinion of the consumer about the physical characteristics of the product.
➢ It consists in knowing the attitude of people towards the same product with different dates of manufacture, to
determine if they would consume it or not.
➢ This method seeks to establish a relationship between the shelf life and the perceived quality of the product.
➢ It is not a method to accurately estimate the shelf life
What is the practical relevance of shelf-life to consumers?
➢ The aim of shelf-life is to help consumers make safe and informed use of foods.
➢ The shelf-life of foods should only be considered valid, if the product is purchased
intact and undamaged.
➢ Consumers should always follow manufacturers’ instructions on storage,
particularly temperature and use of the product after opening.
➢ It is also recommended that consumers consider shelf-life information when
purchasing foods to avoid unnecessary food waste.
➢ For example, unlike foods with use-by-dates, many foods with best-before dates
will be safe to eat even if this date has passed.
https://www.eufic.org/en/healthy-living/article/food-shelf-life-and-its-importance-for-consumers
Water relationships in Foods
Water activity (aW) - Important parameter in HACCP plan in food industries
• Water is present in all food.
• It usually takes two forms: Bound and free or available water or unbound
• Water that is bound to different molecules such as proteins and carbohydrates
• Available or (Free) water can support the growth of bacteria, yeast and mould, which can
affect the safety and quality of food.
Water Content in Food
✓ Water content, or moisture content, is a measurement of the total water contained in a
food.
✓ It is usually expressed as a percentage of the total weight:
w-d
Mw (wet basis) = ----- x (100)
w
Mw = moisture content on a wet percent basis
w = wet weight
d = dry weight
Is water content and water activity same?
NO. It is different
What is water activity?
➢ Water activity (aw) is expressed as the ratio of the vapour pressure in a food (P) to the
vapour pressure of pure water (P0).
➢ It predicts whether water is likely to move from the food product into the cells of
microorganisms that may be present.
➢ aw= P/P0
➢ For example, a water activity of 0.90 means the vapour pressure is 90% of that of pure
water.
➢ Water activity increases with temperature due to changes in the properties of water
such as, the solubility of solutes such as salt and sugar, or the state of the food.
➢ It ranges from 0 to 1 (pure water).
What is water activity?
✓ The higher the water activity, the faster that microorganisms like bacteria, yeast and mold
will be able to grow.
✓ Most pathogenic bacteria need a water activity of 0.90, while spoilage molds need at least
0.70 or higher for growth
✓ In simple words water activity is the measurement of the water that is not bound to other
food constituents and is available for microbial growth, chemical and biochemical
reactions.
✓ William James Scott (1950) began to correlate the water content of the food with its
tendency to spoil. Over the period of time, it is realized that free water is more important
for the stability of food than total amount of water. So, determining water activity of a
medium helped in controlling the spoilage due to microbial growth.
What is water activity?
• For a food to have a useful shelf life without relying on refrigerated storage, it is
necessary to control either its acidity level (pH) or the level of water activity (aW) or a
suitable combination of the two. This can effectively increase the product's stability
and make it possible to predict its shelf life under known ambient storage conditions.
• Food can be made safe to store by lowering the water activity to a point that will not
allow dangerous pathogens such as Clostridium botulinum and Staphylococcus aureus
to grow in it.
• Water has a significant contribution to the growth of microorganisms. Microorganisms
require water for transporting nutrients, cellular wastes and maintaining cell shape. So,
when microorganisms get sufficient amount of water they flourish in that environment
leading to microbial spoilage and may cause food borne illnesses.
What is water activity?
Based upon water content foods can be classified into three categories-
• Low moisture food (water activity <0.60),
• Intermediate moisture foods (water activity 0.60- 0.85) and
• High Moisture foods (water activity > 0.85) .
✓ Higher the water activity, the chances of spoilage are higher. Bacteria require higher
values of water activity for growth than fungi. Below 0.60, there is no microbial growth
✓ Controlling water activity can help in maintaining chemical stability of the product. Water
acts as a solvent and reactant in many biochemical reactions. So, water activity affects
the non-enzymatic browning (Millard reaction), lipid oxidation, protein denaturation,
starch gelatinization and retrogradation.
✓ With the reduction in water activity, the rate of these reactions also decreases
What is water activity?
The typical water activity of some foodstuffs
https://pmp.errc.ars.usda.gov/wateractivity.aspx
The water activity of a solution or solid can be determined by sealing it in a chamber
and measuring the relative humidity after the system has come to equilibrium
Water activity is in practice
usually measured as equilibrium
relative humidity (ERH).
Determination of water activity
• Lowering water activity, food can be made safe to store.
• The table below shows water activity levels that can support the growth of
particular groups of organisms.
Biological Importance of lipids
What are lipids?
➢ Any of a class of organic compounds that are fatty acids or their derivatives and
are insoluble in water but soluble in organic solvents.
➢ They are organic compounds that contain hydrogen, carbon and oxygen atoms.
➢ They form the framework for the structure and function of living cells.
➢ They are soluble only in non-polar solvents.
The biological significance of lipids
1. Structural lipids form the material of the biological membrane. Example: Phospholipid
2. They are stored as reserve food.
3. Forms protective coverings of fruits and leaves in plants
4. Fats are deposited around the vital structures for protection against pressure and
mechanical injury.
5. Steroids in the form of hormones control many physiological processes.
6. Phospholipids and cholesterol make biological membranes. Phospholipids are like
gatekeepers that let some molecules into your cells
• Steroid hormones send messages in cells.
• Bile salts from cholesterol help digest fat.
Properties of Fatty Acids
• Fatty acids undergo the same reactions as other carboxylic acids, such as esterification
and acid-base reactions.
• The acidities of fatty acids do not vary greatly, as indicated by their pKa values.
• The solubility of fatty acids in water decreases as chain length increases so that longer-
chain fatty acids have little effect on the pH of an aqueous solution.
• Auto-oxidation occurs when unsaturated fatty acids undergo a chemical change. The
presence of trace metals speeds up the process, which requires oxygen (air).
• Ozonolysis- Ozone is capable of degrading unsaturated fatty acids. This reaction is
used in the synthesis of azelaic acid from oleic acid.
Uses of Fatty Acids
• They are used in the production of many food products.
• In the production of soaps, detergents, and cosmetics.
• Soaps are fatty acid sodium and potassium salts. Some skin-care products contain fatty
acids, which can help maintain the appearance and function of healthy skin.
• Dietary supplements containing fatty acids, particularly omega-3 fatty acids, are also
widely available.
• Fatty acids are also converted to fatty alcohols and fatty amines via their methyl esters,
which are factors in the development of surfactants, detergents, and lubricants.
• Emulsifiers, texturizing agents, wetting agents, anti-foam agents, and stabilising agents
are all examples of fatty acids.
What Are Omega-3s?
Omega-3s are a type of polyunsaturated fatty acid found in the body. These fatty acids can
serve several important functions in the body, as they can provide a source of energy while
also serving as an essential building block of cell membranes in the body.
There are three main types of omega-3 fatty acids:
• Alpha-linolenic acid (ALA), an omega-3 precursor
• Docosahexaenoic acid (DHA)
• Eicosapentaenoic acid (EPA)
What Are the Health Benefits of Omega-3s?
They can have a vital influence on how cells in your body interact with each other.
Consuming omega-3 fatty acids regularly could offer the following health benefits:
• Support cholesterol levels already within the normal range
• Maintain a healthy blood pressure
• Support overall heart health
• Maintain joint health
• Support overall emotional wellness
Omega-3s
Cholesterol Structure Cholesterol in Mammalian Membranes
• Organic molecule consisting of steroid rings with a
hydroxyl group • Cholesterol interacts with the fatty acid tails
• Two methyl groups and a hydrogen tail of phospholipids to moderate the properties
• Altogether it is formed by 27 carbon atoms of the membrane
• 45 hydrogen atoms, and 1 hydroxyl group
• (C27H46O) having a molecular weight of 386.664
g/mol.
• Cholesterol is an amphipathic molecule
Cholesterol
✓ Cholesterol is a fundamental molecule necessary for the maintenance of cell
structure and is vital to various normal biological functions.
✓ It is a key factor in lifestyle-related diseases including obesity, diabetes,
cardiovascular disease, and cancer.
✓ Owing to its altered serum chemistry status under pathological states, it is now
being investigated to unravel the mechanism by which it triggers various health
complications.
✓ Numerous clinical studies in cancer patients indicate an alteration in blood
cholesterol level (either decreased or increased) in comparison to normal healthy
individuals.
To date 13 Nobel Prizes have been awarded for studies related to cholesterol
Mayengbam et al. (2021) Influence of cholesterol on cancer progression and therapy
• Cholesterol metabolism
is tightly regulated in
normal cells.
• Approximately 80% of
total cholesterol in
humans is normally
biosynthesized in the
body and 20% is
secured from the diet.
• It is either present in
free form or as a
cholesterol ester with
fatty acids.
Mayengbam et al. (2021) Influence of cholesterol on cancer progression and therapy
Phospholipids
• Phospholipids are composed of a phosphate group, two alcohols, and one or two fatty
acids.
• One end of the molecule has a phosphate group and one alcohol; this end is polar,
meaning it has an electric charge and attracts water (hydrophilic).
• Phospholipids are important in membranes (phospholipid membrane) because of their
amphipathic nature (containing both hydrophobic and hydrophilic groups).
• They form a two-layer structure called the lipid bilayer, with the polar head facing out
on each surface to interact with water and the neutral "tails" driven inward and pointing
toward one another.
• All cell membranes are built on a lipid bilayer, which is nearly impermeable to ions and
most polar molecules.
Phospholipids
Chemical Structure
Briefly phospholipids are:
• A glycerol molecule, two fatty acids, and an alcohol-modified phosphate group
constitute phospholipids.
• The phosphate group is a hydrophilic, negatively charged polar head.
• Hydrophobicity is found in the uncharged, nonpolar tails of fatty acid chains.
• Because the tails are hydrophobic, they face inward, away from the water, and meet
in the membrane's inner region.
• The hydrophilic heads are attracted to both intracellular and extracellular fluid and
face outward.
• Micelles are lipid molecules that form a spherical shape in aqueous solutions when
phospholipids are mixed with water.
Types of Phospholipids
There are two types of phospholipids, which are listed below.
• Glycerophospholipids
They are the most widely used form of phospholipids found in biological membranes,
also called phospholipid membranes. It is made up of phospholipids produced from
glycerol.
• Sphingophospholipids
They are key components of myelin and can be found in large quantities in the brain and
nervous system. It's composed of sphingosine and alcohol.
The example of phospholipids are Phosphatidylserine and Phosphatidylcholine
Biological Importance of Phospholipids
The storage of foods is limited by non enzymatic, enzymatic, or microbial reactions
that alter edible quality of foods, including deterioration, appearance, texture,
aroma, flavor, nutrition, and safety and functional properties. Enzymatic reactions
with respiration at the tissue surface can lower oxygen concentration and
indirectly promote non enzymatic oxidation of myoglobin. When the raw milk is
stored for long time at low temperature before heat treatment, the
psychrotrophic bacteria can multiply and produce extracellular heat-stable
enzymes. Proteinases and lipases produced by psychrotrophic bacteria in raw
milk can cause noticeable hydrolysis of proteins and lipids within 3–7 days. The
heat-stable enzymes produced by psychrotrophic bacteria can cause spoilage of
food products. Cream and butter are more susceptible to spoilage by heat-stable
lipases than proteinases. The bacterial proteinases and lipases from
psychrotrophic bacteria such as Pseudomonas, Aeromonas cause flavor and
texture defects in raw meat and fish.
Enzymatic Food Spoilage
https://doi.org/10.1002/9781119237860.ch24 2016
Food Pigments & Flavoring Agents:
Importance, types and sources
Types of Pigments Major natural pigments in Foods
Types of Natural Pigments
Summary of major natural pigment classes in the market and their application in foods.
Microbial Pigments in the Food Industry—Challenges and the Way Forward
Organic pigments (synthetic) are generally categorized
into six types
Importance of Pigments
Bioactivity of
natural
pigments
Color stability of anthocyanins, betalains, carotenoids, and chlorophylls to heat, oxygen, light, and pH
change. Adapted from Ngamwonglumlert et al. (2017).
Pulscd clcctíic ficld assistcd cxtíactio⭲ of ⭲atuíal food pigmc⭲ts a⭲d coloíi⭲gs fíom pla⭲t matíiccs
Benefits of Flavor
• Good flavor, or even anticipated good flavor suggested by the appetizing appearance
and smell of the food, cause saliva to gather in the mouth.
• Saliva contains an enzyme that begins digestion, especially of the starches and it also
helps moisten and soften for food swallowing.
• The stomach also responds to pleasant flavors by secreting extra gastric juices.
• So the better the flavor, the better our digestion, and the more comfortable healthy and
well nourished we are.
References
