Gelatin is the product of partial hydrolysis of collagen. Pectin is a kind of polysaccharide, which consists of homogeneous polysaccharide and impurity polysaccharide. Ming collagen molecule is a spirochete interwoven with three polypeptide chains. Through the treatment of technological process, collagen molecular spirochete denatures and decomposes into α component of a single polypeptide chain (α chain), β component consisting of two α chains and γ component consisting of three α chains, and molecular chain fragments between them that are smaller than α component or larger than γ component.
Gelatin can be divided into photographic gelatin, edible gelatin and industrial gelatin according to its properties and uses. According to different uses, the quality requirements of gelatin are different. When used as an adhesive, adhesive strength is mainly required. When used in photography, food, medicine and other fields, the purity of products is emphasized.