The white color of bone soup is fat, and the soup is boiled into thick white, which is mainly the "credit" of fat. During the heating process, the fat is emulsified to form stable fat droplets suspended in water, and the soup is milky white. Usually, the more fat, the whiter the soup. Fat is a triglyceride composed of glycerol and fatty acids, in which the molecule of glycerol is relatively simple, but the types and lengths of fatty acids are different. Therefore, the nature and characteristics of fat mainly depend on fatty acids, and the types and contents of fatty acids contained in fat in different foods are different. There are more than 40 kinds of fatty acids in nature, so various fatty acid triglycerides can be formed; Fatty acids usually consist of 4 to 24 carbon atoms.