The main functional factor of TG is transglutaminase. This enzyme is widely found in the human body, advanced animals, plants and microorganisms. It can catalyze the cross-linking between and within protein molecules, the linking between proteins and amino acids, and the hydrolysis of glutamine residues within protein molecules. Through these reactions, the functional properties of various proteins, such as nutritional value, texture structure, taste and storage life, can be improved.