Starch: generally extracted from corn or sweet potato;

Flour: Flour is a kind of powder ground from wheat. According to the content of protein in flour, it can be divided into high gluten flour, medium gluten flour, low gluten flour and gluten-free flour.

Raw flour: Strictly speaking, it is the general name of all kinds of starch, which is mainly used for thickening. In the north, it is called dough powder.

Specific differences:

1. Flour is made by peeling wheat or other grains and grinding them into powder; Raw flour, or starch, is a polysaccharide produced by protein and other substances separated from flour. Raw flour is insoluble in water, especially after being poured into hot water, it will absorb water and expand to form a viscous translucent liquid.

2. Flour is rich in protein, fat, carbohydrates and dietary fiber, while starch is only a part of flour, and its composition is not as comprehensive as flour.

And the colors of flour and raw flour are different. Flour is slightly yellow than starch, and the color of starch is pure white.

4. Mud Rub a little flour with your hands, and then you will feel slippery, while rubbing some starch with your hands will feel a little astringent.

Flour is generally used to make steamed buns and steamed buns, or to wrap food and then put it in an oil pan for frying. Starch is generally used to make soup, which can make the soup clear, sticky, delicious and beautiful.

Extended data:

Starch is the polymerization of glucose molecules and the most common storage form of carbohydrates in cells. Starch, also known as starch powder in catering industry, has the general formula of (C6H 10O5)n, and the stage of hydrolysis to disaccharide is maltose, with the chemical formula of C 12H22O 1 1. Monosaccharide (glucose) was obtained after complete hydrolysis, and the chemical formula was C6H 12O6.

Starch includes amylose and amylopectin. The former is a spiral structure without branches; The latter consists of 24~30 glucose residues connected end to end by α- 1, 4- glycosidic bond, and the branch is α- 1, 6- glycosidic bond. Amylose is blue when exposed to iodine, while amylopectin is purple when exposed to iodine.

This is not a chemical reaction between starch and iodine, but the central hole of the starch spiral can just accommodate iodine molecules, and they form a blue-black compound through van der Waals force. Experiments show that a single iodine molecule can't make starch blue. In fact, it is iodine molecular ion (I3) that makes starch blue.

Reference materials? Baidu encyclopedia-flour

Baidu encyclopedia-starch

Baidu encyclopedia-raw flour