The gelatin or collagen peptide is extracted from collagen according to the degree of hydrolysis. There are large differences in these three things.
Collagen
Collagen is the raw material of gelatin and collagen peptide. It is the general term of some protein with similar structures. There are currently 27 different collagens and type I collagen is most common. The collagen monomer contains three polypeptide chains which are entangled with each other to form a triple-strand helix. These monomers make up tiny fibers that are linearly arranged to constitute the collagen. It has strong mechanical properties and makes a big contribution to supporting and protecting. Widely distributed in tissues such as skin, skeletal, tendon, cornea, cartilage, collagen is the most abundant protein in mammalian.
Gelatin
Gelatin is a product obtained by moderate hydrolysis. The acid, alkali, enzyme and thermal energy break down hydrogen bonds, peptide bonds and other covalent cross-link. The triple helix in collagen is completely disappeared to form three random coiled peptide chain and some smaller peptide fragments. These peptide chains can cross-link together with two or three chains or exist freely. The molecular weight of these polypeptides ranges from tens of thousands to hundreds of thousands Dalton. When the molecular weight becomes smaller, the insoluble collagen will be transformed into gelatin that is insoluble in cold water but can be dissolved in hot water. After the hot gelatin solution cooled down, it forms elastic jelly. It is widely used in confectionery such as soft candy, marshmallow, ice cream and cake as whipping agent, thickener, stabilizer, emulsifier and jellying agent.
Collagen peptide
Collagen peptide is also named hydrolyzed gelatin, gelatin hydrolysate or collagen protein. It is the product obtained by degradation of gelatin. From collagen to collagen peptide, the triple helix structure is completely loosened to become three free peptide chains. Then, they are continuously hydrolyzed into smaller peptide fragments and even oligopeptides that are composed of less than 20 amino acids. The wide molecular weight distribution is from thousands to tens of thousands of Dalton. Hydrolyzed gelatin is a neutral food additive that is soluble in cold water. It has no taste or odor and does not affect the original food taste, nor does it form a gel that changes the food texture. Because of its small molecular weight, it can be absorbed by your skin or intestine directly, or absorbed after simply digestion. Long-term use of collagen peptides can bring about improved skin health, stronger bones and relief of arthritis, so it is widely used in cosmetics, low-fat foods, sports drinks as a nutritional supplement.