At present, the general term "whole grains" refers to rice, wheat, soybeans, corn and potatoes, while grains other than rice and flour are customarily referred to as whole grains, so whole grains also refer to food crops. Therefore, it is generally believed that grain is a general term for food crops.
Origin of grains
Wuguzi
[1] The earliest record of the term "five grains" can be found in The Analects of Confucius. According to the Analects of Confucius, more than 2,400 years ago, Confucius took his students on a long trip, and Zilu fell behind. He met an old farmer who was carrying a bamboo basket with a stick and asked him, "Have you seen the master?" The old farmer said, "Who is the master if you don't work on all fours?" Grains mean five kinds of grains. Books older than The Analects of Confucius, such as The Book of Songs and The Book of Classics, contain only "hundred grains" but no "five grains". From 100 grains to five grains, have the types of food crops decreased? That's not true. At the beginning, people often gave a proper name to several different varieties of a crop one by one, so there were many lists. Moreover, the word "hundred" here is only used to refer to many meanings, and there are not really one hundred kinds. The appearance of the term "five grains" indicates that people have a clear concept of classification, and at the same time, it reflects that there were five main food crops at that time. When the term "five grains" was first created, there was no record of what it meant. The earliest explanation we can see now was written by Han people. There are two main explanations of Han people and people after Han: one is rice, millet, millet, wheat and glutinous rice (that is, soybean); Another way of saying it is hemp (refers to marijuana), millet, millet, wheat and glutinous rice. The difference between these two statements is that one has rice without hemp, and the other has hemp without rice. Although pockmarked seeds can be used for food, they are mainly used for weaving. Valley refers to grain, and the former statement does not include hemp in grain, which is more reasonable. But on the other hand, at that time, the economic and cultural center was in the north, rice was a southern crop, and the cultivation in the north was limited, so it was possible to have hemp in the grain without rice. The crops mentioned in the Book of Records of the Historian Tianguanshu, "Every year is beautiful and evil" (predicting the abundance of years), are wheat, millet, millet, glutinous rice and hemp, which belong to the latter statement. Probably because of these reasons, Han people and people after Han people have two different interpretations of grain.
The whole grains (20 pieces) combine these two statements, and there are six main crops: rice, millet, millet, wheat, glutinous rice and hemp. There are four articles devoted to agriculture in the famous book Lu's Spring and Autumn Annals (works in the third century BC) in the Warring States Period, among which the article Shenshi talks about the advantages and disadvantages of planting crops, millet, rice, hemp, rice and wheat. A grain is a millet. These six crops are exactly the same as the six mentioned above. These six kinds of crops are also mentioned in the Spring and Autumn Annals of Lu. Obviously, rice, millet, millet, wheat, rice and hemp were the main crops at that time. The so-called grain refers to these crops, or five of these six crops. However, with the development of social economy and agricultural production, the concept of five grains is constantly evolving. Now the so-called five grains are actually just the general name of food crops, or refer to food crops in general.
As early as the Yellow Emperor's Classic of Internal Medicine, Su Wen put forward the principle of "five grains for nourishment, five fruits for help, five livestock for benefit, five dishes for filling, and the smell is combined to supplement the essence", which also explained the dominant position of whole grains in the diet. Nutrition believes that the best diet is actually a balanced diet. The first principle of a balanced diet requires that foods should be as diverse as possible. One is the diversification of species, that is, we should try to eat all kinds of foods such as grain, meat, beans, milk, eggs, vegetables, fruits, oils and fats; The other is the diversity of species, that is, we should try to eat all kinds of foods in each category, such as pork, beef, mutton, chicken, fish, rabbit, duck and so on. The same is true of grain. It is not in line with the principle of balanced diet to eat only polished rice and white flour, but also coarse grains, such as millet, corn, buckwheat, sorghum and oats. There is an understanding of this ancient Chinese medicine book Huangdi Neijing, which says, "Five grains are for nourishment, five fruits are for help, five animals are for benefit, and five dishes are for filling". In the five grains, rice and wheat are generally considered to belong to flour and rice; Coarse grains refer to other grains except rice and wheat, that is, corn, buckwheat, oats, millet, sorghum and potatoes mentioned above. Some trace elements in coarse cereals, such as iron, magnesium, zinc and selenium, are more than those in flour and rice. These trace elements are of great value to human health. The contents of potassium, calcium, vitamin E, folic acid and bioflavonoids in coarse cereals are also richer than those in flour and rice. Coarse grains are good for diabetes. Replacing part of flour and rice with coarse grains is good for controlling blood sugar in diabetic patients. Recent studies show that the postprandial blood sugar changes after eating coarse grains and miscellaneous beans are generally less than those of wheat and ordinary rice, which is good for controlling blood sugar in diabetic patients. At present, some foreign diabetic dietary guidance organizations have suggested that diabetic patients should choose coarse grains and miscellaneous beans as far as possible, and they can be eaten as staple food or part of staple food. However, the ability of these coarse grains and miscellaneous beans to maintain postprandial blood glucose response is also different. Such as oat, buckwheat, barley, Redmi, black rice, adzuki bean and lentils, can obviously relieve postprandial hyperglycemia of diabetic patients, reduce blood sugar fluctuation within 24 hours, reduce fasting blood sugar and insulin secretion, which is beneficial to blood sugar control of diabetic patients.
Although the concept of five grains has been in existence for more than two thousand years, the status of these crops in the national food supply has changed from time to time. Millet, millet and other crops in the five grains have the characteristics of drought tolerance, barren tolerance and short growth period, so they occupy a particularly important position in the original cultivation of dry land in the north. By the Spring and Autumn Period and the Warring States Period, the characteristics of "keeping old and being easy to do" were discovered, and it became an indispensable food for people at that time together with millet. At the same time, it has been found that lodging wheat (winter wheat) can be planted in late autumn and early spring, and it can solve the problem of green and yellow. In addition, the invention of stone mill at this time has greatly improved the palatability of wheat from grain to pasta, which has attracted widespread attention and developed into one of the main food crops, and is comparable to millet. In the Confucian classic "Spring and Autumn Annals", it is not a book, but it is a book if the grain and wheat fail. It can be seen that saints attach the most importance to wheat and grain among the five grains. Agronomists Zhao Guo and Fan Sheng Zhi in the Western Han Dynasty devoted themselves to popularizing wheat planting in Guanzhong area. The increase of Guanzhong population in Han Dynasty was closely related to the development of wheat farming. Until the Tang and Song Dynasties, the population in the north was more than that in the south. But after the Tang and Song Dynasties, the situation changed. China's population growth is mainly concentrated in the southeast, which is the land of Chu and Yue, which has been called "vast territory and sparsely populated" since Qin and Han Dynasties. In the Song Dynasty, the population of the south surpassed that of the north, which was estimated to be 6: 4. Since then, the population density in the south has been much higher than that in the north. The increase of population in South China is inseparable from rice production. Rice is very suitable for planting in the southern region with abundant rainfall, but at first it was inconspicuous and even excluded from the grain. However, it came from behind. After the Tang and Song Dynasties, the status of rice in the national food supply was increasing day by day. According to Song Yingxing's estimation in the Ming Dynasty, at that time, seven tenths of rice was dominant in the food supply, while rice, wheat, millet, millet and other food crops, together, accounted for only three tenths of the total, which had been relegated to a secondary position. Soybean and hemp had withdrawn from the category of food crops and were only used as vegetables. However, when some crops withdrew from the ranks of grain crops, some crops joined the ranks of grain crops. At the end of the Ming Dynasty, corn, sweet potato and potato were introduced to China one after another and became an important part of the main grain crops in modern China.