Introduction to Basic Food Science

and Nutrition
FSN1
What is Nutrition?
Nutrition: the study of food, including
 How food nourishes our bodies

 How food influences our health

 Nutrition is a relatively new discipline of science.

Why is Nutrition Important?

 Nutrition contributes to wellness.

 Wellness: the absence of disease
 Physical, emotional, and spiritual health

 Critical components of wellness:

Nutrition
Physical activity
What is Food?
Definition
- “Food is any article whether simple, mixed or compounded,
which is used as food or drink, confectionery or condiment. It
includes articles used as components for such.”
- To the biologists, food is simply defined as any matter eaten
by an to sustain life and nourish the body.
- The physiological definition which nutritionists use for food is:
“any substance which taken into the body provides energy,
builds and repairs tissues and regulate bodily processes.
- To the normal individual, food is something that can
alleviate hunger.
Food Science
 is the study of the chemical, physical and microbiological
nature of foods and any transformation that food undergoes
as reflected in its characteristics and properties. From the
time the food is produce to the time it is ultimately
consumed, the application of the principles of food science
is practiced.
Branches of Food Science
 Food technology
 Food chemistry
 Food microbiology
 Food engineering
 Food processing or manufacturing
Related Fields of Study:
 Nutrition
 Physics
 Economics
 Agriculture
 Fisheries
 Biology
 Food legislation
 Disease control
 Sociology
 Anthropology
 Psychology
Food Quality
 is a composite of several
criteria determined by stimuli
coming from the food and the
attitude of values attached
by the consumer to the food.
Nutritional Quality
 Foods are sources of
substances called nutrients
which are responsible for
the physiological roles of
food to give energy, build
and repair body tissues
and regulate bodily
processes.
Digestibility
 digestibility refers not only to
the completeness of
digestion and absorption
but also to the general
feeling and after-effect of
eating.
Palatability
The palatability factors are eating qualities of a food as judge by the
human senses include of the following:
1. Visual Perception
The appearance of an object depends on radiant energy or light
waves emanating from the object observed and that impinge on the
retina of the eye.
2. Odor detection
The olfactory nerves of the nose are sensitive to volatile substances
emitted by aromatic compounds in foods.
3. Taste stimuli
Taste sensations are attributed to the chemical components of foods
that stimulate the taste buds of the tongue.
The Human Tongue
Palatability
4. Tactile sensation
mouth feel and feeling by touch depend on stimuli of nerve endings
on the mucous linings of the mouth and on the skin.
5. Flavor
This sensory quality is a composite of odor, taste, mouth feel and skin.
Chemical Composition of Food
 Food contain mainly water, proteins, carbohydrates
and fats as the macronutrients, these compounds
are presents comparatively larger amounts than
others are measurable in terms of grams per 100
grams which represent percentage by weight.
What Are Nutrients?
Nutrients
 The chemicals in foods that are critical to
 human growth and function.
Essential Nutrients are critical to the body for the body
to function properly:
 Water
 Protein
 Carbohydrates
 Fats
 Minerals
 Vitamins
Water
is the most abundant
compounds in foods.
- water is the most common
dispersing medium.
- there are three physical states
of water; solid as ice, liquid; and
gas as steam or water vapor.
Protein
 are large, complex organic
compounds composed of amino
acid as the building units linked
together in peptide linkages as the
primary structure or the backbone
of the protein molecule. The
secondary structure of protein
refers to its conformation as either
the helix type or the pleated sheet
form.
Carbohydrates
 The most common carbohydrates in foods are
sugars and starches which are in digestible forms
and therefore are available sources of energy to
humans.
Fats
 are organic
compounds that
belong to a bigger
group of water-
insoluble substances
called lipids.
Minerals
 are inorganic constituents as contrasted to the
organic compounds: protein, carbohydrates, fats
and vitamins. The striking similarity between the salts
of sea water and the mineral content of protoplasm
supports the view that life might have originated
from the sea.
Vitamins
 are potent organic compounds which occur in
minute quantities in foods. Vitamins are classified
according to solubility as the fat-soluble vitamin A,
D, E and K and the water-soluble B-complex
vitamins and ascorbic acid or vitamin C.
CLASSIFICATION OF PROTEINS
Simple Proteins
Albumins: blood (serumbumin); milk (lactalbumin); egg white (ovolbumin); lentils
(legumelin); kidney beans (phaseolin); wheat (leucosin). Globular protein; soluble in
water and dilute salt solution; precipitated by saturation with ammonium sulfate
solution; coagulated by heat; found in plant and animal tissues.
Globulins: blood (serum globulins); muscle (myosin); potato (tuberin); Brazil nuts
(excelsin); hemp (edestin); lentils (legumin). Globular protein; sparingly soluble in
water; soluble in neutral solutions; precipitated by dilute ammonium sulfate and
coagulated by heat; distributed in both plant and animal tissues.
Glutelins: wheat (glutenin); rice (oryzenin). Insoluble in water and dilute salt solutions;
soluble in dilute acids; found in grains and cereals.
Prolamines: wheat and rye (gliadin); corn (zein); rye (secaline); barley (hordein).
Insoluble in water and absolute alcohol; soluble in 70% alcohol; high in amide
nitrogen and proline; occurs in grain seeds.

Protamines: sturgeon (sturine); mackerel (scombrine); salmon (salmine); herring

(clapeine). Soluble in water; not coagulated by heat; strongly basic; high in arginine;
associate with DNA; occurs in sperm cells.

Histones: Thymus gland; pancreas; nucleoproteins (nucleohistone). Soluble in water,

salt solutions, and dilute acids; insoluble in ammonium hydroxide; yields large
amounts of lysine and arginine; combined with nucleic acids within cells.
Scleroproteins: Connective tissues and hard tissues. Fibrous protein; insoluble in all
solvents and resistant to digestion.

Collagen: connective tissues, bones, cartilage, and gelatin. Resistant to digestive

enzymes but altered to digest gelatin by boiling water, acid, or alkali; high in
hydroxylrpline.

Elastin: Ligaments, tendons, and arteries. Similar to collagen but cannot be converted
to gelatin.

Keratin: Hair, nails, hooves, horns, and feathers. Partially resistant to digestive enzymes;
contains large amounts of sulfur, as cystine.
Conjugated Proteins
Nucleoproteins: cytoplasm of cells (ribonucleoprotein); nucleas of chromosomes
(deoxyribonucleoprotein) viruses, and bacteriophages. Contains nucleic acids,
nitrogen, and phosphorus. Present in chromosomes and in all living forms as a
combination of protein with either RNA or DNA.

Mucoprotein: saliva (mucin); egg white (ovomucoid). Proteins combined with amino
sugars, sugar acids, and sulfates.

Glycoprotein: bone (osseomucoid); tendons (tendomucoid); carilage

(chondromucoid). Containing more than 4% hexosamine, mucoproteins; if less than
4%, then glycoproteins.

Phosphoproteins: milk (casein); egg yolk (ovovitellin). Phosphoric acid joined in ester
linkage to protein.
Chromoproteins: hemoglobin; myoglobin; flavoproteins; respiratory
pigments; cytochromes. Protein compounds with such nonprotein
pigments as heme; colored proteins.

Lipoproteins: serum lipoprotein; brain, nerve tissues, milk, and eggs.

Water-soluble protein conjugated with lipids; found dispersed widely in
all cells and all living forms.

Metallo proteins: ferritin; carbonic anhydrase; ceruloplasmin. Proteins

combined with metallic atoms that are not parts of a nonprotein
prosthetic group.
Derived Proteins
Proteans: edestan (from elastin) and myosan (from myosin). Results from short action of
acids or enzymes; insolvent in water.

Proteases: intermediate products of protein digestion. Soluble in water; uncoagulated

by heat; and precipitated by saturated ammonium sulfate; result from partial
digestion of protein by pepsin or trypsin.

Peptones: intermediate products of protein digestion. Same properties as proteases

except that they cannot be salted out; of smaller molecular weight that proteases.

Peptides: intermediate products of protein digestion. Two or more amino acids joined
by a peptide linkage; hydrolyzed to individual amino acids.
Pigments

The variety of colors seen in foods is due chiefly to pigment substances within the plant
or animal cell.

Browning Reactions in Foods

1. Caramelization
2. Maillard browning reaction
3. Oxidation reactions of polyphenols and ascorbic acid

Enzymes
are organic catalysts which are protein in nature and are produced by living cells.
Useful Application of Enzymes in Foods
1. Meat tenderizers
2. Invertase
3. Amylases
4. Pectinases
5. Microbial enzymes
 Undesirable reactions of Enzymes in Foods
1. Enzymatic browning
2. Rancidity
3. Maturation
4. Spoilage

Flavor Components
Flavor components in foods include: sugar, acids, aldehydes, eaters,
alcohols, ketones and sulfuric compounds.
pH in Foods
Acidity may be expressed in terms of normality or molarity which is the total acidity or
total acidity or total hydrogen ions in a solution and in terms of pH which represents
the free or active hydrogen ion concentration. The latter is referred to as active
acidity and in food science is more important than the former measure of total
titrable acidity.

At 22ºC, pure distilled water which is neutral dissociates into hydrogen and hydroxyl
ions at a concentration of 0.0000001 each. This amount may also be expressed as
1/10 or 10 (-7) which is still cumbersome to write..
APPLICATION OF pH IN FOOD SCIENCE
1. Jelly-making – for gel formation, an optimum pH of 3.2 is needed.
2. Bread-making – a dough with a pH value of 5 is favorable to attain products with
good volume and texture.
3. Soda crackers – a pH of 7is desirable to obtain a crisp, cream-colored product.
4. Canning foods – foods for canning are classified on the basis of pH value.
5. Control of microbial growth involves the regulation of pH in foods to inhabit
multiplication of spoilage agents.
6. Taste of sourness – as the pH increases, the intensity of sour taste increases.