starch is a nutrient stored in plants, which exists in seeds and tubers. The starch content in all kinds of plants is high, including 62% ~ 86% in rice, 57% ~ 75% in wheat, 65% ~ 72% in maize and 12% ~ 14% in potato. Starch is an important part of food, and it feels a little sweet when chewing rice, etc. This is because amylase in saliva hydrolyzes starch into disaccharide-maltose. After food enters the gastrointestinal tract, it can also be hydrolyzed by salivary amylase secreted by the pancreas, and the formed glucose is absorbed by the small intestine wall and becomes a nutrient for human tissues. Partial hydrolysis of amylopectin can produce a mixture called dextrin. Dextrin is mainly used as food additive, glue, paste, and in the manufacture (finishing) of paper and textiles.

Chengfen is also called Chengmian, Tingfen and Wheat Starch. It is a kind of gluten-free flour, and its ingredients are wheat. Raw flour can be used to make all kinds of snacks, such as shrimp dumplings, vermicelli, rice rolls, etc.

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 is mostly used for gouzi. The raw flour used in mainland China and Hongkong is corn flour, while the common flour used in Taiwan Province is too white. In Chinese cooking, raw flour is often used as one of the cured meat materials to soften the meat quality, in addition to making food taste smooth.

custard powder is a kind of pre-mixed powder, which is processed by the manufacturer in advance. It can be reduced to thick custard sauce by adding a small amount of liquid and stirring. Generally, the liquid used is water or milk. I use custard powder, which is usually used to make milk stuffing. It is really fragrant and the color is yellow, which is very attractive.