Proteins are made up of amino acids linked together by peptide bonds formed between the carboxyl group of one amino acid and the amino group of the next. Native proteins are those found in living tissues, while denatured proteins have had their structure modified, such as by heat, acids, or alkalis. Gelatin is a partially degraded protein formed from collagen that helps make firm gels. Milk proteins include casein and whey proteins; casein forms a skin when milk is heated. Eggs contain various proteins in the white and yolk; the white can be beaten into a foam used in foods like meringues. Novel sources of protein include single cell proteins from microbes, leaf proteins from plants, and

1. Protiens
Compiled by:
Vandana Mahajani

2. Basic structure of protiens
Proteins are made up of amino acids which are organic acids
with a carboxyl group and amino group.
Peptide linkage
The carbon of the carboxyl group of one amino acid
combines with the nitrogen group or amino group of another
amino acid with the loss of one molecule of water. This bond
is called the peptide bond.

3. Native proteins
Proteins found in living tissues of plants and animals are
called native proteins.
Denatured proteins:
Is defined as modification in the original structure of native
proteins
This happens due to 1. acids, alkalies2. rise in temp. 3. too
much beating.

4. Functional properties of protein rich foods
Gelatin is a partially degraded protein formed from collagen.
Collagen is the intercellular substance between cells.
Long thin fibers of gelatin help in making firm gels at low
temperature.
Whips, sponges , and creams are prepared by whipping the
cold viscous gelatin sol.

5. Milk cookery
Milk proteins are of two types.
1. Casein 2. Serum or whey proteins – albumins and
globulins
When milk is heated a skin of casein forms on top that
blocks calcium salts and milk fats.
The colour and flavour of condensed milk is because of the
browning caused by lactose and milk protein.
While making paneer acid is added which reduces the
stability of casein and it coagulates forming a gel.

6. Eggs
Nine proteins are dispersed as sol in egg white.
Proteins and lipids are present in egg yolk. Some like lecithin
are emulsifying agents. Cholesterol is also present .
Egg white is a vicious sol with proteins dispersed in it. It can be
beaten into a foam.
Foams are found in different stages 1. foamy. 2. soft peaks
3.Stiff peaks 4. dry.
Meringues are egg white foams with sugar incorporated in it.. It
is used a stopping in alaska cream, pie fillings, chocolate pies,
macaroons. Souffle and fondue and cakes also use egg foams
in preparation.
In bread making gluten is the complex protein that makes the
matrix for the bread .
The colour of the meat is due to presence of myoglobin and
hemoglobin.
The presence of water (hydration )of proteins determines the
tenderness of meat

7. NOVEL SOURCES OF PROTEIN
Single cell protein
Bacteria, yeast, algae, fungi
Leaf protein
Grass, foliage, harvested crops.
Oilseed residues
Groundnut, cotton, sesame.
Textured vegetable protein
Soya beans