Cereals, Pulses - Composition and nutritive value, Principles of cooking

Cereals

The principle cereal crops are rice, wheat, maize, jowar, ragi and bajra.

Composition and nutritive value.

Cereals are the main source of energy. Rice provides 345 calories and 6.8 grams of protein per 100 grams and wheat provides 341 calories and 12.1 grams of protein per 100 gms. Ragi is a rich source of calcium and iron. Wheat and ragi are rich in fibre. Whole grain cereals are an important source of B vitamins in our diet.

Principles of cooking

Gelatinisation

When starch granules are mixed with water and cooked the grains absorb water and swell. This process is known as gelatinisation.

Dextrinisation

If starch is subjected to dry heat, it is converted to dextrin, giving a brown colour. This is called dextrinisation.

Gluten formation

Glutenin or glutelin and gliadin are proteins present in wheat. During the mixing of a dough the long strands of glutenin evidently becomes aligned in the direction of mixing and forms a film that envelopes the starch granules in the dough. In the presence of water and with mechanical agitation, the protein fraction forms a tough elastic complex called gluten, which is capable of retaining gases and by doing so, a leavened product is obtained. Due to its elastic property, the dough can be rolled to prepare chapathis or puris.

Pulses

Pulses are edible fruits or seeds of pod bearing plants. The major pulses which are used are red gram dhal, bengal gram dhal, black gram dhal and green gram dhal.

Composition and nutritive value

Pulses contain 55 to 60% starch. Every 100 grams of pulses provide about 350 calories and 22 grams of protein. Pulses are excellent source of B complex vitamins particularly thiamine, folic acid and pantothenic acid. Soyabean provides 43 grams of protein per 100 grams. Whole grams are good sources of protein, B-vitamins and fibre.

Principles of cooking

Many pulses particularly whole grams, which have hard outer covering need soaking prior to cooking. Addition of sodium bicarbonate hastens the cooking process, but is not advisable because it destroys the B vitamins.