Fortification of surimi gels by tuning the synergetic effect of multiple enzyme-related factors
Yadong Zhao, Jiajia Li, Ganping Wei, Xiaoguo Ying, Bin Zheng, Pingping Gao, Rusen Zhou
Abstract
Enzymes play critical roles in surimi gelation and gel physiochemical properties. Understanding and thus tuning enzyme-related multiple factors are warranted for preparing high-quality surimi products with satisfactory textural profiles. In this study, three enzyme-related factors, i.e., Ca2+ required for endogenous TGase activation, whey protein concentrates (WPC) as an endogenous proteases inhibitor, and MTGase capable of catalyzing protein crosslinking, are explored regarding their gel-enhancing performance. Ca2+, WPC and MTGase at their optimal concentrations (3.5%, 5% and 1%, respectively) are introduced into surimi gels together, leading to significant increases in the hardness and WHC of the obtained surimi gels by 156% and 25%, correspondingly. Next, a mechanism underpinned by the synergetic effect of Ca2+, WPC and MTGase on improving surimi gel properties is proposed. Ca2+ could activate endogenous TGase for proteins crosslink, whereas WPC avoids the proteolytic disintegration of gel networks by inhibiting endogenous proteases, and MTGase catalyzes the ε-(γ-glutamyl) lysine linkages between ε-amino groups of lysine residues and γ-carboxyamide groups of glutamine residues on myosin heavy chains. These beneficial effects then induce a well-developed three-dimensional gel network. Collectively, we propose and validate a new strategy based on the major enzyme-related factors during gelation to improve surimi gel properties, which may provide useful guidelines on tuning the textural properties of meat-based products in the food industry.