Anti-freeze Activity of Cod Skin Collagen Peptide and Its Mechanism of Action
[Objective]To study the antifreeze activity of cod (Gadus) skin collagen peptide,and to explore the mechanism of anti-freezing denaturation of surimi as an antifreeze.[Methods]The antifreeze activity of cod skin collagen peptide was determined by measuring its molecular weight distribution and thermal hysteresis activity (THA).The protein concentration,total sulfhydryl content,Ca2+-ATPase activity and secondary and tertiary structure changes of myofibrillar protein in Channa argus surimi were determined by adding 0.5％,1.0％ and 3.0％ cod skin collagen peptide to the surimi and by freezing and thawing the surimi for five times.And the changes of water distribution and microstructure of fish fillets were determined after repeated freeze-thaw cycles,the antifreeze activity of cod skin collagen peptide was analyzed,and its mechanism was explored.[Results]The molecular weights of cod skin collagen peptides were mainly distributed in 1000—3000 u,and the thermal hysteresis activity was 1.9 ℃,and they were able to reduce the particle size of myofibrillar protein and prevent protein aggregation.Frozen surimi treated with 1.0％ cod skin collagen peptides had high myofibrillar protein concentration,Ca2+-ATPase activity,and total sulfhydryl content.In addition,during the 5 freeze-thaw cycles of surimi,cod skin collagen peptide was able to maintain the stability of the secondary and tertiary structure of the myofibrillar protein,which prevented the protein from undergoing freeze denaturation,and at the same time,it was able to regulate the size of ice crystals,reduce the mechanical force damage caused by ice crystals to the fish flesh,and improve the water holding capacity of surimi.[Conclusion]Cod skin collagen peptide can be used as a phosphorus-free antifreeze to resist protein freezing denaturation in surimi.The results of this study provide important basic data for developing cod collagen peptide into a new,safe and efficient phosphorus-free antifreeze.
万方数据
维普
