拉曼光谱分析牛肉贮藏过程中肌红蛋白结构的变化  

Structural Changes of Myoglobin during Beef Storage as Analyzed by Raman Spectroscopy

作　　者：张同刚[1] 罗瑞明[1] 李亚蕾[1] 马梦斌 周亚玲 ZHANG Tonggang;LUO Ruiming;LI Yalei;MA Mengbin;ZHOU Yaling(School of Agriculture,Ningxia University,Yinchuan 750021,China)

机构地区：[1]宁夏大学农学院,宁夏银川750021

出　　处：《食品科学》2019年第7期15-19,共5页Food Science

基　　金：国家自然科学基金地区科学基金项目(31660442)

摘　　要：以牛肉为研究对象,采用拉曼光谱技术研究贮藏时间对肌红蛋白结构的影响。结果表明:随着贮藏时间的延长,肌红蛋白二级结构中的α-螺旋含量呈现降低的趋势,β-折叠结构含量则呈现先升高后下降的趋势,β-转角含量呈现先降低后升高的趋势,无规卷曲含量呈现逐渐增大的趋势;肌红蛋白二硫键由g-g-t与t-g-t构型逐渐向g-g-g构型转变,肌红蛋白分子间二硫键部分被破坏,肌红蛋白分子间作用力降低,肌红蛋白氧化状态与蛋白质的二级结构、酪氨酸与色氨酸残基暴露出的数量有很强的相关性,贮藏过程中肌红蛋白的结构逐渐疏散无序,氨基酸残基微环境发生改变。本实验从蛋白质二级结构层面揭示了贮藏时间影响牛肉色泽变化的微观机理。The effect of storage time on the structure of myoglobin in beef was studied by Raman spectroscopy. The results showed that the α-helix content of myoglobin gradually decreased, the β-sheet content initially increased followed by a decrease, the β-turn content showed the opposite trend to β-sheet, and the random coil content increased progressively with increasing storage time. Furthermore, increasing storage time of beef resulted in configurational transformation of disulfide bonds in myoglobin from gauche-gauche-trans and trans-gauche-trans to gauche-gauche-gauche. Disulfide bonds were partially damaged and the intermolecular force of myoglobin reduced. The oxidation status of myoglobin had a strong correlation with the secondary structure and the amount of exposed tyrosine and tryptophan residues, respectively. The structure of myoglobin became disorderly scattered and the microenvironment of amino acid residues changed during storage. These results could explain the molecular mechanism of the effect of storage time on the color change of beef.

关 键 词：拉曼光谱 贮藏时间 肌红蛋白 二级结构 

分 类 号：TS251.1[轻工技术与工程—农产品加工及贮藏工程]