Food Category: Cereals

Cereals are the seeds of grass from Graminae family with caryopsis
fruit where the seed wall fuses with ovary to form the husk. The roman
word "Ceres" means the goddess of grain. Cereals are the staple diets
which fulfill most calories and half of the protein requirement. They
are the good source of starch and vitamin B and improve the quality of
pulse proteins. They are used as thickening agents as cornflour in
custards & white sauce, rice flour in pulses, vermicelli in payasam,
and macaroni in soups; as coating agent - flour in batter; in
beverages - malted; desserts - riz au lait, pilaf; breakfast food -
idli/dholka; easy to cook products - pastas, cornflakes, riceflakes;
covering for stuffing - samosas, stuffed pastas. Wheat, rice and maize
are the major cereals and oat, barley, rye, sorghum, millets etc. are
minor cereals.
An overall structure of cereal grain
Bran (Pericarp): Long rectangular cells, tear off during ripening
Aleurone cell layer: Rich in nicotinic acid and less phytic acid
Endosperm: Full of starch and proteins
Embryo: It is separated from endosperm by scutelum which helps in
mobilizing the stored food between embryo and endosperm.
Features of cereals:
Energy: 100gms of cereals give more than 340 kcal of energy.
Carbohydrates: Carbohydrates constitute 80% of dry matter in cereals.
a) Crude fibres - Cellulose, hemicellulose, pentosans
b) Soluble carbohydrate - Starch, dextrin, sugar
Proteins: High amount of protein lies within the embryo, scutellum and
aleurone layer. In the scutellum, protein concentration increases from
the center to the periferi. Protein in cereals is deficient in lysine
and rich in methionine so cereals with pulses create a mutual
supplementation. Rice protein is of better quality. Protein contains
albumin, globulin, prolamines (gliadins), & glutelins.
Lipids: Lipids are found more in germ and bran. In cereals we find
triglycerides of palmitic, oleic and linoleic acid; and also
phospholipids and lecithin. 50% of lipid requirement is supplied by
cereals.
Minerals: 95% of minerals in cereals are phosphates and sulphates of
Mg, Ca & Ka. Phosphorus in phytin is not available for absorption. On
germination, cereals contain Cu, Zn, Mn in small quantities.
Vitamins: Vit. A or C are not found in cereals except in maize
(carotenes). Oil from cereals is rich in vit. E.
Enzymes: Cereals contain amylase, protease, lipase and oxido
reductase. On germination, α-amylase activity increases. Proteases are
relatively more in the germ. Lipases are responsible for the
appearance of fatty acids during storage.