Tofu, made from soybean called "plant meat", originated in Bagong Mountain, Anhui Province, China, with a history of more than 2,000 years. Tofu has high nutritional value. No wonder some people joked that tofu was the "fifth invention" besides the four great inventions in ancient China.
There are many kinds of tofu.
A square and simple piece of tofu can be a small cold dish at home, a main course of a hotel, or even a restaurant featuring tofu, such as Huaiyang Tofu Banquet. There are many kinds of tofu. In addition to the traditional North Tofu and South Tofu, there have been many tofu with "technical content" in recent years, such as lactone tofu, kapok tofu, silk tofu, and even bright red strawberry tofu, bright green vegetable juice tofu and peanut nutritious tofu.
Different tofu has different nutrition.
Associate Professor Fan Zhihong from the College of Food Science and Nutritional Engineering of China Agricultural University told the reporter of Life Times that the traditional tofu in China is made by soaking soybeans in clear water, foaming and softening, grinding them into soybean milk, and then using brine or gypsum "brine" to solidify protein particles dispersed in soybean milk. Tofu on the market now mainly includes north tofu, south tofu, lactone tofu and "fake tofu".
North tofu. Also called old tofu, it is generally made of brine (magnesium chloride). Its characteristics are high hardness, strong toughness, low water content, rough taste, slightly sweet and bitter, but protein content is the highest, suitable for frying, frying and stuffing. Although the northern tofu is bitter, it is high in magnesium and calcium, which helps to lower blood pressure and vascular tension, prevent cardiovascular diseases and strengthen bones and teeth.
South tofu. Also known as tender tofu and soft tofu, it is generally made of gypsum (calcium sulfate), which is characterized by tender and smooth texture, elasticity, large water content, sweet and fresh taste, and protein content above 5%. Cooking should be mixed, fried, stewed, boiled and roasted to make soup.
Lactone tofu. The old generation of brine and gypsum were abandoned, and gluconolactone was used as coagulant, and trehalose, vegetable gum and other substances were added to keep water. Although the texture is delicate and the taste is tender, it is not as nutritious as traditional tofu. This is because, first, the soybean content is low and it tastes like tofu; Secondly, the calcium and magnesium of tofu mainly come from gypsum and brine, but the gluconolactone coagulant used now contains neither calcium nor magnesium, so its nutritional value is reduced.
Fake tofu Readers can easily find that there are many "pattern tofu" on the market: Japanese tofu, almond tofu, milk tofu, egg tofu and so on. Although they are all called "tofu", they all look moist and smooth and taste smooth, but they have nothing to do with tofu. Because there is no soybean in the raw materials of these "tofu foods". Take Japanese tofu as an example. In fact, it is the "egg tofu" made of eggs in colloidal solution and solidified.
How to choose tofu
How to choose tofu? Fan Zhihong taught you a few tricks. First, the color of tofu should be yellowish. If it is too white, it may be added with bleach, which is not suitable for purchase. Secondly, a good boxed lactone tofu has no gaps in the box, flat surface, no bubbles and no water, and there is no shaking feeling when you hold it in your hand. When you open the box, you can smell a little bean fragrance. Third, tofu itself is a high-protein food, which is easy to rot. It is best to buy it in a place with good refrigeration equipment; Fourth, after buying home, you should immediately soak it in clear water, put it in the refrigerator, take it out before cooking, and make it within 4 hours to keep it fresh.