Raw flour refers to starch in Chinese food, which is used for thickening and sizing when cooking. There are many kinds of raw flour, such as sweet potato starch, water bean powder used in Sichuan cuisine and corn starch. There are many kinds of raw flour. Generally speaking, the academic concept of corn starch thickening is that it has the characteristics of water absorption, cohesiveness and smoothness when gelatinized by heat. When the dish is close to maturity, pour the prepared powder juice into the pot to thicken the marinade and increase the adhesion of the marinade to the raw materials, thus increasing the powder and concentration of the soup and improving the color and taste of the dish. Chestnut powder belongs to corn starch and is a carbohydrate formed by plant photosynthesis. It is a polysaccharide composed of a single type of sugar unit, which is naturally synthesized by plants. Starch is abundant in seeds, tubers and roots of plants. The varieties of starch include corn, rice, wheat, potato, sweet potato and cassava starch. In addition to the above main varieties, there are acorn, canna taro, kudzu root, Polygonum multiflorum starch and so on. Raw powder (white powder), also known as bean powder and water chestnut powder, is made from broad beans or water chestnut. Raw flour has a wide range of uses and can be used as a seasoning for cooking, bean jelly and pancake stalls. Mainly used for sizing and snagging when processing meat raw materials. Raw flour does not refer to any kind of starch. Raw flour is a term that often appears in mainland recipes and Hong Kong-style recipes, and it is mostly used for hooks. The raw flour used in Chinese mainland and Hongkong is corn flour, while the flour commonly used in Taiwan Province Province is Taibai. In China cooking, raw flour is often used as one of the cured meat materials to soften the meat quality, besides making the food taste smooth.