The grain contains high starch content, about 60%-70%. Although there are differences in the morphology and size of different cereal grains, the structure is similar. The outer layer of the granules is a husk, an aleurone layer, an endosperm, and an embryo at the other end. The chemical composition of the different parts is different. Wheat is an important grain, and the endosperm is about 83% of the grain. The main component is starch, and there are proteins and other materials; the aleurone layer is about 4.5%, containing fiber, protein, B vitamins; germ about 2.5 %, with protein, vitamins, etc.
The fine flour that people love to eat is white in color, looks good, and is delicious. It is obtained from the fine processing of wheat grain. It is derived from the endosperm and other parts are removed. Therefore, other nutrients are also removed, and the nutrients contained are lower than the original wheat. grain.
Fine flour is loved by people, but its nutrition is poor. Long-term consumption can cause certain nutrients, especially vitamin B1, to cause beriberi. This situation has attracted attention. The U.S. government enacted a law in 1941 that required the addition of a certain amount of nicotinic acid, vitamin B1, and iron equal to refined flour as a supplement. Although the amount of increase is not as good as the amount of wheat flour processed into the loss of flour, the effect is good and nutritional deficiency is basically eliminated. The refined flour with added nutrients is called fortified flour. After World War II, the law was abolished and encouraged to eat whole-grain bread. It was made from whole wheat flour made from whole-grain wheat flour. The color is white and light brown, but nutrition is good and the number of people is increasing. Now it is very common.
Steamed buns and bread are fermented foods made from flour. Utilizing the unique properties of gluten proteins, water is kneaded into a tough dough. Coated with carbon dioxide bubbles, the volume increases, a soft structure is formed, and the palatability is strong. A small amount of sugar in the dough during fermentation produces carbon dioxide and alcohol via yeast, which is lost during heating. The difference between steamed buns and bread is at the heating temperature. The former is steamed at a temperature of 100°C and the latter is baked at a temperature of 230°C to 280°C. The outer skin of the bread is heated and a small amount of sugar breaks down into caramel and turns brown. The bread used to be the main food in Western countries and was later introduced to China. The people in the city eat more, but it is mainly made from refined flour. Whole-wheat bread and whole-wheat bread should be promoted.
The nutrition of corn is good. People in northern China once grinded the whole corn grain into powder and made it into a nest. Because its protein has no gluten and cannot be made into fermented foods, it has a rough texture and is not as tasty as steamed bread and is not easily accepted. However, corn has good nutrition and low prices. As a source of good staple foods, it is necessary to make more efforts on taste and make people love eating. Snack food made of corn is very popular, such as popcorn, corn flakes, etc., which are common in China and Western countries. The corn flakes are coarsely ground corn kernels, which are steamed, pressed into thin slices and dried. They are commonly eaten in Western countries.
Cereals contain dietary fiber, which is part of the cell wall and cannot be digested for consumption. It has long been considered a food waste. But since the mid-1970s, its importance has been recognized. Dietary fiber is highly absorbent, up to 5-10 times its own weight, increases the volume of food in seventeen items, promotes intestinal peristalsis, facilitates bowel movements, has the function of cleaning the intestine, and has the function of preventing several diseases. It is good for the body and is highly valued. If the food contains toxic substances, it can be quickly discharged with the feces, reducing or avoiding harmful effects. Dietary fiber has a preventive effect on chronic degenerative diseases such as cardiovascular disease, diabetes, and colon cancer.
Whole grains are a good source of staple foods. China encourages the consumption of coarse grains. The U.S. Food Nutrition Pyramid ranks whole grain foods at the lowest level of the tower. It is an important category of food and gives high priority to these opinions: these opinions are correct and people are urged to follow .
“People use food as their dayâ€, and people eat in the day to obtain nutrition and maintain their health. People in different regions have different dietary habits, but they all use cereal as their staple food, such as taro, rice, and bread. Cereals are the main source of body heat.