1. Soy protein is a standout among plant-based proteins. It is considered a high-quality protein, comparable to animal protein. However, strictly speaking, the amino acid score of soy protein (a measure of protein nutritional value) is still not as high as that of proteins found in eggs, meat, and dairy. Therefore, the protein powder widely used in clinical practice is whey protein, not soy protein.
2. Soy products like tofu, dried tofu, yuba (tofu skin), and vegetarian chicken can be a source of calcium. However, soy products like soy milk, silken tofu, tofu pudding, yuba (tofu skin), and thousand-layer tofu contain less calcium. This is because the latter products are not made with calcium-containing coagulants (such as nigari or gypsum).
3. The nutritional importance of soy products for vegetarians is unparalleled. Vegetarians should consume more soy products. The "Dietary Guidelines for Chinese Residents (2016)" suggests that a full vegetarian diet should include 50-80 grams of soybeans daily (equivalent to a large block of about 400 grams of tofu), while lacto-ovo vegetarians should consume 25-60 grams of soybeans (or an equivalent amount of soy products) daily—twice the amount recommended for the general population.
4. Fermented soy products like fermented tofu (sufu), douchi (fermented black beans), and soybean paste are typically high in salt and are not generally classified as recommended healthy foods. However, they do have a unique advantage: they contain vitamin B12, which is not found in other plant-based foods. This is particularly important for vegans. The "Dietary Guidelines for Chinese Residents (2016)" also recommends that vegans consume 5-10 grams of fermented soy products daily.
5. Soybeans are rich in phospholipids, especially lecithin, which is one of the two primary sources for producing the health supplement "lecithin" (soy lecithin). The other source is egg yolk (egg yolk lecithin).
6. Soybeans contain a variety of phytochemicals, including sterols, oligosaccharides, saponins, soy isoflavones (phytoestrogens), soy fiber, phytic acid, and trypsin inhibitors. Almost all of these components are extracted and sold as health supplements. In products like tofu, dried tofu, and yuba (tofu skin), most of these substances are lost and only a small amount remains. However, in products like soy milk, boiled soybeans, douchi (fermented black beans), and soybean powder, these substances are largely retained. In soybean oil, all of these substances are completely absent.
7. Raw soybeans are toxic. Harmful substances they contain, such as phytohemagglutinin, are sufficient to cause food poisoning. Fortunately, these toxic substances are destroyed during cooking, making cooked soybean products safe. Raw or undercooked soy milk, however, is very dangerous, and there have been many cases of poisoning from its consumption.
8. Soybeans have become one of the inexpensive raw materials for the food industry. In addition to being used to extract soybean oil and produce health supplements, soy protein and phospholipids are widely used in various meat products, beverages, nutritional foods, snacks, and other items. It's safe to say they are ubiquitous.
9. "Soybeans" primarily refer to yellow soybeans, black soybeans, and green soybeans. Their nutritional value is fundamentally different from that of other legumes like mung beans, red beans, lentils, fava beans, and kidney beans. The latter beans contain a high amount of starch (over 50%) and very little fat, whereas soybeans have almost zero starch content and are rich in fat (which can be used to extract oil).