关键词: 丝胶肽；胶原肽；鲢鱼酶解产物；疏水性；构效关系

Abstract: In order to investigate the influence of antifreeze peptide properties on its protective effect on myofibrillar proteins in frozen surimi, the present study was conducted to characterize the properties of three antifreeze peptides (sericin peptides, collagen peptides and silver carp hydrolysates), and we analyzed the changing pattern of myofibrillar protein properties under different freezing conditions, and constructed a correlation model between myofibrillar protein properties and frozen storage parameters and antifreeze peptide properties using least absolute shrinkage and selection operator (Lasso) regression. The results showed that all antifreeze peptides used in the study were “hyperactive” antifreeze peptides with thermal hysteresis activity (THA) (> 0.60 ℃), low molecular mass (< 10 000 Da), high hydrophilicity (θ < 30°) , and polar amino acid content of more than 60%; the antifreeze peptides were able to significantly mitigate the negative effects of frozen storage on myofibrillar proteins. The mean content of myofibrillar proteins in frozen surimi with added antifreeze peptides was 50.44–54.47 mg/g, the mean Ca2+-ATPase activity was 1.61–1.67 U/mg, the mean surface hydrophobicity index increased only by 39.91%–42.40% when compared with that of fresh surimi, and the rate of myofibrillar protein denaturation was much lower than that of the control group without antifreeze peptides. The Lasso regression model explained the effects of antifreeze peptide properties on changes in the properties of myofibrillar protein in frozen surimi, demonstrating that antifreeze peptides with lower molecular mass and higher THA contributed to slowing down the decline in myofibrillar protein content, Ca2+-ATPase activity, surface hydrophobicity, and characteristic indexes. The differences in the hydrophilicity/hydrophobicity of antifreeze peptides resulted in differences in their interactions with ice crystals and proteins, and consequently caused different effects on surimi myofibrillar proteins. This study provides a theoretical basis for the application of antifreeze peptides and the quality regulation of surimi products and also provides a direction for the development of novel efficient antifreeze agents.

Key words: sericin peptides; collagen peptides; sliver carp hydrolysates; hydrophobicity; structure-activity relationship