羟自由基氧化体系对银鲳肌原纤维蛋白生化特性及其构象单元的影响  

Effects of Hydroxyl Radical Oxidation on Biochemical Properties and Conformation of Myofibrillar Protein in Pampus argenteus

作　　者：陈霞霞[1] 杨文鸽[1] 吕梁玉 胡小超[1] 高喜乐[1] 

机构地区：[1]宁波大学海洋学院,浙江省动物蛋白食品精深加工重点实验室,浙江海洋高效健康养殖协同创新中心,浙江宁波315211

出　　处：《食品科学》2016年第23期123-128,共6页Food Science

基　　金：海洋公益性行业科研专项(201305013);浙江省动物蛋白食品精深加工重点实验室开放基金项目(2015)

摘　　要：采用FeCl_3-VC-H_2O_2羟自由基模拟氧化体系,探究不同氧化剂浓度和氧化时间对银鲳肌原纤维蛋白生化特性及其空间结构的影响。结果表明:随着氧化时间的延长,高浓度(1.0 mmol/L H_2O_2)和低浓度(0.1 mmol/L H_2O_2)氧化剂组均使银鲳肉肌原纤维蛋白的羰基含量、表面疏水性、二聚酪氨酸含量上升,总巯基含量下降;相比于低浓度氧化剂组,高浓度氧化剂组的影响更加明显。拉曼图谱显示:随氧化时间延长和氧化剂浓度增大,银鲳肌原纤维蛋白微环境极性总体呈增强趋势,酰胺Ⅰ带向长波方向移动,其α-螺旋比例下降,而β-折叠比例上升。结论:在羟自由基氧化体系中,银鲳肌原纤维蛋白发生了显著氧化,导致其结构和生化指标发生改变。This study explored the impact of different oxidant concentrations and oxidation times on biochemical characteristics and spatial structure of myofibrillar protein in back muscles of Pampus argenteus using FeCl_3-VC-H_2O_2 hydroxyl radical-generating systems. The results showed that Pampus argenteus myofibrillar proteins were attacked by free radicals generated from FeCl_3-VC-H_2O_2 systems, causing changes in some amino acid side chains to produce polymers. With the extension of oxidation time, both the high（1.0 mmol/L H_2O_2） and low concentration（0.1 mmol/L H_2O_2） oxidant groups showed a significant increase in myofibrillar protein carbonyl content, surface hydrophobicity and dityrosine content, and a decrease in total sulfhydryl content, but the effect of the high oxidant concentration was more significant. Raman spectroscopic analysis indicated that, with the increase in oxidation time and oxidant concentration, the microenvironmental polarity of myofibrillar protein was generally enhanced. The amide Ⅰ band was shifted to longer wavelength along with a reduction in α-helix content and an increase in β-sheet content. In conclusion, P. argenteus myofibrillar protein could be oxidized in hydroxyl radical-generating systems, leading to its structural and biochemical changes.

关 键 词：羟自由基 蛋白氧化 拉曼光谱 银鲳 空间构象 

分 类 号：TS251.1[轻工技术与工程—农产品加工及贮藏工程]