琼胶寡糖对冻藏南美白对虾蛋白质功能特性的影响

Effects of agar-oligosaccharide on protein functional properties of Litopenaeus vannamei during frozen storage

目的探究琼胶寡糖对冻藏南美白对虾蛋白质功能特性的影响。方法采用蒸馏水、1.5%和3.0%三聚磷酸钠、1.5%和3.0%琼胶寡糖浸泡南美白对虾,分别在冻藏第0、20、40、60、80和100 d时进行取样,测定其肌原纤维蛋白溶解性、浊度、乳化性(emulsifying activity index,EAI)、起泡性(foaming capacity,FC)和热稳定性。同时,利用苏木精-伊红(hematoxylin and eosin,HE)染色观察肌肉组织微观结构。结果在冻藏过程中,琼胶寡糖与三聚磷酸钠的作用效果相当,且1.5%、3.0%琼胶寡糖显著改善了虾仁肌原纤维蛋白溶解性、EAI和FC的降低以及浊度的增加情况,增加了其热稳定性。HE染色结果显示,新鲜虾仁内部肌肉组织排列紧密有序,而冻藏100 d后,各处理组虾仁肌肉纤维均有不同程度的扭曲断裂,其中3.0%琼胶寡糖组虾仁肌纤维间的连接仍十分紧密,组织结构最为完整。结论琼胶寡糖能有效保持冻藏南美白对虾蛋白质功能特性,维持肌肉组织结构,提高虾类品质。本研究为水产品抗冻剂的开发提供了借鉴和参考。

Objective To explore the effects of agar-oligosaccharide on the protein functional properties of Litopenaeus vannamei during frozen storage.Methods The shrimp were soaked in distilled water,1.5%and 3.0%sodium tripolyphosphate,and 1.5%and 3.0%agar-oligosaccharide,respectively.Samples were taken on 0,20,40,60,80,and 100 days after frozen storage,and the solubility,turbidity,emulsifying activity index(EAI),foaming capacity(FC),and thermal stability of myofibrillar protein in shrimp were measured on 0,20,40,60,80,and 100 days of frozen storage,respectively.Meanwhile,the tissue microstructure of shrimp muscle was observed by hematoxylin and eosin(HE)staining.Results During the frozen storage process,the effects of agar-oligosaccharides and sodium tripolyphosphate were found to be equivalent.The addition of 1.5%and 3.0%agar-oligosaccharides significantly inhibited the reduction in the solubility of shrimp myofibrillar protein,EAI,as well as FC,and the increased of the turbidity,rising the thermal stability of shrimp.The results of HE staining revealed that the internal muscle tissue of fresh shrimps exhibited a tightly arranged and orderly structure.However,after 100 days of frozen storage,the muscle fibers of shrimps in each treatment group showed varying degrees of distortion and breakage.Notably,the 3.0%agar-oligosaccharide group exhibited the tightest connections between muscle fibers and the most complete organizational structure.Conclusion Agar-oligosaccharide can effectively maintain protein functional properties,muscle tissue structure,and improve shrimp quality.This paper provides a reference for the development of antifreeze agents in aquatic products.