外源抗氧化剂α-生育酚在河蟹肌肉脂肪-蛋白质氧化体系中的作用  

Effects of the Antioxidant α-Tocopherol on Lipid-Protein Systems from Crab Muscles

作　　者：刘小莉[1] 彭欢欢[1,2] 夏秀东 周剑忠[1] 刘源[2] 赵江涛[1] LIU Xiaoli;PENG Huanhuan;XIA Xiudong;ZHOU Jianzhong;LIU Yuan;ZHAO Jiangtao(Institute of Agricultural Products Processing,Jiangsu Academy of Agricultural Sciences,Nanjing 210014,China;College of Food Sciences and Technology,Shanghai Ocean University,Shanghai 201306,China)

机构地区：[1]江苏省农业科学院农产品加工研究所,江苏南京210014 [2]上海海洋大学食品学院,上海201306

出　　处：《食品科学》2018年第14期51-56,共6页Food Science

基　　金：江苏省河蟹产业技术体系项目

摘　　要：为了考察添加α-生育酚对河蟹肌肉中氧化脂肪-蛋白质体系的影响,以采集的河蟹肉为研究对象,通过测定蟹肉肌原纤维蛋白中巯基含量、表面疏水性、二级结构变化以及蛋白电泳情况,研究常温贮藏条件下氧化脂肪-蛋白质模拟体系中肌原纤维蛋白的变化。结果显示,蟹油经过12、24 h氧化后,脂肪酸组成发生变化,不饱和脂肪酸相对含量明显下降。添加24 h氧化蟹油的河蟹肌肉中,活性巯基含量的减少和表面疏水性的增加较为显著,氧化程度越高,α-螺旋、β-折叠相对含量越少,β-转角则越多;添加α-生育酚的处理组与相应的对照组相比,活性巯基含量的减少、表面疏水性的增加显著减缓,α-螺旋、β-折叠相对含量较多,β-转角较少,十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)结果显示,抗氧化剂的添加对肌原纤维蛋白降解有一定的抑制效果,条带光密度分析显示仅有个别组间条带有显著差异,SDS-PAGE用于检测蛋白质氧化程度不及活性巯基和表面疏水性指标灵敏。研究表明氧化蟹油能够加速蛋白质的变性,且氧化程度越高,效果越显著;α-生育酚对氧化脂肪诱导的蛋白质变性具有显著的抑制作用。The goal of this research was to explore the antioxidant effect of α-tocopherol on lipid-protein systems from crab muscles. Changes in the sulfhydryl content, surface hydrophobicity, secondary structure and sodium dodecyl sulfatepolyacrylamide gel electrophoresis（SDS-PAGE） profile of myofibrillar protein from the model systems were examined during storage at room temperature. The results showed that after oxidation for 12 and 24 h, fatty acid composition of crab lipids changed; a significant decrease was observed in the content of unsaturated fatty acids. The sulfhydryl content of crab muscles mixed with 24 h oxidized crab lipids decreased and the surface hydrophobicity significantly decreased; as the degree of oxidation increased, the contents of α-helix and β-sheet decreased, while β-turn content increased. Compared with the control group, the addition of α-tocopherol displayed a lower sulfhydryl content and a significantly slower rate of increase in the surface hydrophobicity, as well as an increase in α-helix and β-sheet and a decrease in β-turn. SDS-PAGE showed the inhibitory activity of the antioxidant against the degradation of myofibrillar protein. Optical density analysis using Gel Image System software showed that a significant difference existed between only a few bands, indicating that SDS-PAGE was a less sensitive tool than sulfhydryl content and surface hydrophobicity for evaluating the protein oxidation. The results in this study indicated that oxidized crab lipids could accelerate protein denaturation and the effect was dependent on the degree of oxidization; α-tocopherol had significant inhibitory activity against the consequent protein oxidation.

关 键 词：Α-生育酚 肌原纤维蛋白 脂肪 氧化 

分 类 号：TS254.4[轻工技术与工程—水产品加工及贮藏工程]