Abstract: Transglutaminase (TGase), an efficient protein cross-linking agent, has been widely applied in the meat industry to enhance the quality of meat products by modifying the structure of myofibrillar protein (MP) and consequently improving the heat-induced gel properties of MP. Meanwhile, degree of cross-linking (DCL) is the most important indicator to evaluate the cross-linking effect catalyzed by TGase, which is of particular importance for analyzing the effect of covalent cross-linking catalyzed by TGase on the conformational characteristics, physicochemical properties, and gel properties of MP. Therefore, this article systematically reviews the influential factors of DCL in TGase-catalyzed covalent cross-linking of MP, and dissects the molecular mechanisms of the effect of exogenous additives and novel processing technologies on TGase-catalyzed cross-linking. The aim of this article is to establish the relationship among structural modification, molecular mechanism and quality improvement for TGase-modified MP, which will provide innovative theoretical and technical support for the development of new types of meat products.

Key words: transglutaminase; myofibrillar protein; gel; degree of cross-linking; molecular mechanism