Soybeans include soybeans, black beans and green beans, the most common being soybeans. Soy products are one of the traditional foods of Chinese residents. Because of their good nutrition, they have been widely respected by nutritionists. The nutritional value of soybeans and their products has the following characteristics.

　　1. Rich protein

　　Soybean protein content is as high as 35%～40%, and the amino acid composition in it is close to the needs of the human body, so it belongs to high-quality protein, nutritional value and meat Close to, it can even replace meat protein. The nutritional value of soybean protein is significantly higher than that of various cereals and other plant foods, and soybeans are rich in lysine, which is relatively lacking in cereals, so it should be eaten together with cereals to increase the value of protein in the diet. At present, most of the protein powder health products on the market are derived from soy protein.

　　 2. High fat content

　　The fat content of soybean is 15%-20%, so it is used as a raw material for edible oils. Soy fat is mainly unsaturated fatty acids, and does not contain cholesterol, nutritional value is significantly better than meat fats (mainly saturated fatty acids). In daily foods, there is only one type of food with high protein content, high value, and very little saturated fat, and no cholesterol. In addition, soybeans also contain phospholipids, which have an important role in growth and nerve activity. Lecithin can promote liver fat metabolism, reduce the absorption of cholesterol in the intestine, and help prevent and treat coronary heart disease, hypertension, atherosclerosis and other diseases. At present, most of the lecithin health products on the market are extracted from soybeans.

　　3. Unique sugars

　　The sugar content of soybeans is 25%～30%, but it is almost free of starch (this is essentially different from cereals), and it is basically not Contains simple sugars such as sucrose or fructose. The sugars in soybeans are mainly dietary fiber and oligosaccharides (including stachyose and raffinose). Stachyose and raffinose are the main substances that cause flatulence after eating soy products, and were once considered as harmful ingredients. But now it is known that they can promote the reproduction of probiotic bacteria in the intestine, which is of great significance for promoting bowel movements and maintaining intestinal health, and has the same effect as dietary fiber. At present, there are also health products on the market that are extracted from soybeans and contain soybean oligosaccharides as the main component. They are also known as "bifidus factor", "prebiotic", and "probiotic factor" together with other oligosaccharides. Wait.

　　 4. A good source of calcium

　　Soybeans are rich in calcium, and calcium-containing coagulants are often added during the processing of soybean products, so the calcium content of soybean products is also very prominent. In general, 150 grams of tofu contains roughly the same calcium as 250 grams of milk (260 mg). People who are allergic or intolerant to milk can use soy products as the first choice for calcium supplementation.

　　 5. Rich in B vitamins

　　Soybeans and their products are rich in B vitamins, especially vitamin B2. Soy is also rich in phosphorus, sodium, potassium and other elements, and is a good source of minerals.

　　. Phytoestrogens-soybean isoflavones

　　 soy isoflavones have strong antioxidant effects, help to clear free radicals in the body and inhibit lipid peroxidation, Cardiovascular diseases and certain tumors have certain preventive effects. The structure of soybean isoflavones is similar to the estrogen secreted by the human body and has a weak estrogen-like effect, so it is also called "phytoestrogens". Soy isoflavones can also relieve menopausal symptoms and reduce the risk of osteoporosis in postmenopausal women. There are also many health products on the market that are extracted from soybeans and contain soybean isoflavones as the main component.

　　 7. Other phytochemicals

　　In addition to soybean isoflavones, soybeans also contain phytochemicals such as soybean saponins and soybean sterols.

　　 Studies have shown that soybean saponins also have antioxidant effects, which can help prevent dyslipidemia, atherosclerosis and certain tumors. There are also health products on the market that are extracted from soybeans and contain soybean saponins as the main component.

　　Note: Soy contains anti-nutritional factors such as trypsin inhibitors, phytohemagglutinin, etc. Therefore, eating raw soybeans, drinking raw soy milk or uncooked soy milk can cause food poisoning, nausea, vomiting, and bloating And gastrointestinal symptoms such as diarrhea. However, as long as they are fully heated and boiled, these anti-nutritional factors can be destroyed and their toxicity can be completely eliminated. It is safe and harmless to eat soybean products that have been fully heat-treated.

　　It is precisely because soybeans and their products have good nutritional value and irreplaceable health care, many versions of the "Chinese Dietary Guidelines" formulated by the Chinese Nutrition Society recommend soybeans and their products, and The 2007 edition of the "Dietary Guidelines for Chinese Residents" clearly recommends that each person consume 30 to 50 grams of soybeans or equivalent soybean products per day. Based on the provided protein, this number is converted into soy milk, tofu, dried tofu, and yuba, which are roughly: soy milk 600 ~ 1 000 ml, tofu 130 ~ 220 grams, dried tofu 65 ~ 110 grams, yuba 20 ~ 40 grams . In the case of soy milk (similar to other soybean products), it is almost impossible to drink 600 to 1 000 ml (2 to 4 cups) at a time, so we suggest that it is best to eat soy products twice a day, once for soy milk and once for other soybeans Products, and make the total amount reach the above recommended amount.