Inhibitory mechanism of trypsin combined with d-galactose on freeze-induced gelation and the physicochemical and protein properties of egg yolk
Xin Li, Xin Li, Qun Huang, Yufeng Zhang, Xiang Huang, Yongyan Wu, Fang Geng, Mingzheng Huang, Peng Luo, Xiefei Li, Xiefei Li
Abstract
Frozen egg yolk has the advantages of high nutritional value, convenient transportation, and long-term storage; however, freezing causes gelation of egg yolk, resulting in the deterioration of its functional properties. To minimize freezing-induced changes in the function and structure of egg yolks, the inhibitory effects of d-galactose, trypsin, and a combination of d-galactose and trypsin on freezing-induced gelation of egg yolk were evaluated. The results revealed that d-galactose enhanced the solubility, reduced hardness and viscosity, increased fluidity, and inhibited freeze-induced gelation of egg yolks. Trypsin reduced the turbidity and particle size of egg yolks, further enhanced the polarity and solubility, and partially inhibited freeze-induced gelation. The combination of trypsin and d-galactose exhibited a synergistic effect, with trypsin playing an important role. Overall, this combination exerted a remarkable inhibitory effect on freeze-induced gelation of egg yolk.