Protein: mainly composed of gluten, alcohol soluble proteins, globulin. The essential amino acid composition of general cereal protein is not balanced, such as lysine content is low, threonine, tryptophan, phenylalanine, methionine content is low, so the nutritional value of protein is lower than animal food. Carbohydrates: cereal carbohydrate content is generally about seventy percent, mainly starch, concentrated in the endosperm starch cells, is the most ideal, the most economical source of energy for human beings, our people's dietary life of fifty percent to seventy percent of the energy from cereal carbon hydrate. Fat: cereal fat content is low, such as rice, wheat about one percent to two percent, corn and millet up to four percent. It is mainly concentrated in the pasty layer and germ, and is therefore easily lost or transferred to by-products during cereal processing. The by-products are often used in the food processing industry to extract fats and oils relevant to human health, such as rice bran oil, glutenin and gluten steroids from rice bran, and germ oil from wheat germ and corn. Minerals: cereals contain about one and a half to three percent of minerals, mainly calcium and phosphorus, and more in the form of phytates concentrated in the hull and paste powder layer, digestion and absorption rate is low.