Lactone tofu uses gluconic acid δ -lactone as coagulant, while ordinary bulk tofu generally uses gypsum as coagulant and salt water as coagulant.
/Club/Post/Search? Keywords =% C6% CF% CC% D1%CC% C7% CB% E1%C4% DA% F5% A5 There are many questions about the processing of tofu!
How to distinguish old tofu from tender tofu
Tofu, called "Little Slaughter Sheep" in ancient times, has no flesh and blood. , a white gel with soybean protein as the main component, is made by selecting materials, soaking, grinding, filtering, decocting, patting and squatting. Tofu originated in China in the Tang Dynasty, then spread to Japan, and spread all over the world in modern times.
Tofu is customarily divided into old tofu and tender tofu according to the coagulant used to make tofu and the water content of tofu. Old tofu, also known as north tofu and hard tofu, refers to tofu with a water content of 80%-85%. Generally, brine is used as coagulant, and some use gypsum or acidic yellow serofluid as coagulant. It is characterized by higher pulping temperature, more intense coagulation, higher hardness, stronger toughness, lower water content and more fragrant taste of tofu, and the protein content is above 7.4%.
Tender tofu, also known as south tofu and soft tofu. Generally, it refers to tofu with more water content made of gypsum as coagulant, which is characterized by tender and smooth texture, elasticity and high water content, with a water content of 85%-90% and a protein content of more than 5%. Boxed tofu and bagged tofu with gluconolactone as coagulant also belong to the category of tender tofu.
Types and names of fresh tofu sold in China.
Name, water content, commonly used coagulants, Chinese aliases, and names of similar foreign products of tofu.
Tofu gypsum accounts for about 95%, GDL① Tofu Tofu
South tofu 85% ~ 90% gypsum, GDL, sour water ② tender tofu, soft tofu, water tofu Kinogoshi, silk tofu and soft tofu.
North tofu 80% ~ 85% brine, brine, gypsum old tofu, hard tofu, board tofu, ordinary tofu, ordinary tofu.
60% ~ 70% of dried bean curd, bittern and bittern bean slices (thickness10 ~ 20mm).
Shutter (thickness about 2mm)
Thousands of pieces (about 0.5mm thick) of dried bean curd.
About 90% tofu is filled with GDL box tofu, lactone tofu is filled with tofu, and tofu is packaged.
①GDL: gluconic acid-δ-lactone.
② Sour pulp water: Yellow pulp water does not ferment.
3 stuffed tofu: it does not belong to traditional tofu.
The main types of tofu products abroad are slightly different from those in China. North Tofu and South Tofu are produced in China, while Mohen Tofu and kinogoshi (silk tofu) are produced in Japan. Japanese kapok tofu is equivalent to China's northern tofu in processing methods and product characteristics. Japanese silk tofu is different from southern tofu in China in two aspects: first, the concentration of soybean milk required for silk tofu is high; Secondly, the south tofu needs to be transferred to a mold box after solidification, and a certain amount of water is discharged by applying a certain pressure, while the silk tofu only needs to be cut into pieces and cooled after solidification. In terms of product characteristics, the moisture content of silk tofu is basically the same as that of southern tofu, and sometimes it may be higher. In Japan, the same production method as China South Tofu is soft tofu, but the production consumption is small. The fermented bean curd in China is the same as that in Japan. The concentration of soybean milk and the texture of the product are basically similar to that of silk bean curd, and there is no need to drain it under pressure. Instead, the coagulant is added to the fermented bean curd at room temperature, and at 70 ~ 800C, the coagulant is added to the silk bean curd.
According to the different coagulants used, tofu produced and sold in China can be divided into bittern tofu (also called bittern tofu), gypsum tofu and acid-cured tofu. Salted tofu has the best flavor, but it has poor water retention, low yield and difficult solidification operation. Gypsum tofu has fine texture, good water retention, high product yield and simple solidification operation, but the bean flavor is not enough, and gypsum residue is often accompanied by gypsum smell. Acidified tofu includes yogurt tofu and gluconolactone tofu (referred to as lactone tofu or GDL tofu). Sour tofu has a plain taste, fine texture and good water retention, but its strength is obviously insufficient. Due to the poor water retention of brine tofu, it is generally made into hard north tofu, while acid-coagulated tofu has good water retention and belongs to soft south tofu. Only gypsum tofu with water retention between the two can be made into north tofu and south tofu at the same time. In northern China, salted tofu enjoys a high reputation, but its output is low. Some producers and sellers often use gypsum tofu as salted tofu. Sour tofu is only produced in some areas, and the output is very small. Lactone tofu is a new type of acid-solidified tofu developed in Japan in 1960s, and its solidification mechanism is suitable for making boxed sandwich tofu. Boxed lactone tofu has a long shelf life and is easy to transport. As a new variety of tofu, it is now being sold more and more in the market. However, due to the lack of energy, it is not suitable for intense frying, and it lacks bean flavor and is slightly sour, so it cannot replace the traditional brine gypsum tofu.
For the quality index of fresh tofu, there should be two besides water content, one is the texture parameter of tofu, and the other is the water retention performance of tofu. Texture parameters such as strength, elasticity, cohesiveness and chewiness of tofu directly reflect the taste of tofu, and the water retention of tofu directly affects the yield, circulation and sales of tofu.
Deep-processed tofu is generally north tofu and semi-dried tofu with less water content. The content of tofu processed products is very rich, which can be mainly divided into frozen products (frozen tofu), fermented products (fermented bean curd), halogen products, fried products, smoked products, alkali-soaked products and halogen products according to the production methods, so I won't repeat them here.
The above is only a preliminary classification of traditional tofu products in China. It should be pointed out that there are certain differences between different regions of the same product and between different producers in the same region, whether it is production technology or product quality requirements. Especially in terms of product names and production operations, there are great differences between different regions, which are quite confusing.
Homemade lactone tofu
Tofu is made by soaking soybeans and grinding them, and then adding a proper amount of coagulant to the squeezed soybean milk. Tofu is rich in protein, fat, sugar and inorganic salts such as calcium and phosphorus. It is a kind of food with high nutritional value. Except that the fat content is slightly lower than that of soybean, other nutrients in soybean are preserved. ?
Activity principle?
Gluconic acid-δ-lactone is an excellent food additive with good antiseptic effect. At the same time, it is also a coagulant, which can coagulate protein in soybean milk and make tofu. ?
Activity supplies?
Commercially available bagged soybean milk, glucono-δ-lactone, salt, monosodium glutamate, sesame oil, spicy oil, shrimp skin, yellow wine and sugar. ? Tray scale, spoon, tea urn, iron shelf, alcohol lamp, asbestos net, water bath pot, bamboo chopsticks. ?
Activity steps?
1. Weigh 0.2g of gluconic acid-δ-lactone, put it in a tea jar, add 4 ~ 5ml of water, and stir to dissolve. ?
2. Add another bag of diluted soybean milk (about 220ml), stir it evenly, put it in a water bath pot and heat it in a boiling water bath for 2 ~ 3 minutes, then keep the temperature for about 15 minutes with low fire, and then heat the water bath to boiling. After about a quarter of an hour, the soybean milk will solidify into tofu. ?
3. Add 10g shrimp skin, sesame oil or spicy oil and appropriate amount of sugar as seasoning. ?
4. Add the tofu cooled to normal temperature to the above seasoning, and stir with bamboo chopsticks to taste. ?
Related issues in the activity?
1. If there is no glucono-δ-lactone, some electrolytes such as magnesium chloride and calcium sulfate can be added to the soybean milk.
2. If you have a tool for grinding soybeans, you can use soybeans as raw materials to make tofu. Remove mildew and impurities from soybeans and wash them. Soak soybeans in water at the mass ratio of 1: 7.5 overnight. Grinding soaked and fattened soybeans into coarse soybean milk, filtering with fine gauze, filtering off bean dregs, boiling the obtained filtrate to obtain edible light soybean milk, and making tofu according to the above method.