草鱼肌原纤维蛋白与特征腥味物质的结合作用

The Interactions of Myofibrillar Protein with Characteristic Fishy Odor Compounds in Grass Carp

为了探究草鱼肌原纤维蛋白与特征腥味物质的结合作用,本文建立肌原纤维蛋白-腥味物质(己醛、庚醛、辛醛和壬醛)相互作用体系,采用顶空-气相色谱-质谱联用法分析腥味物质与肌原纤维蛋白的结合能力、分子间作用力,结合差示扫描量热法、紫外、荧光和拉曼光谱等技术分析结合后肌原纤维蛋白热稳定性、二级结构的变化。结果表明,肌原纤维蛋白与选定的4种特征醛类腥味物质的结合能力随着醛类物质链长的增加而增加,并且醛类物质的存在使蛋白质分子结构展开,α-螺旋转变成β-折叠和β-转角结构,蛋白质的荧光强度和热稳定性降低;醛类腥味物质与草鱼肌原纤维蛋白之间的相互作用主要为疏水相互作用,少部分是氢键或离子键。

The present study aimed to illustrate the mechanism of grass carp’s myofibrillar protein absorbing fishy odor compounds by establishing the myofibrillar protein-fishy odor compounds(hexanal,heptanal,octanal and nonanal)system.The binding capacity and molecular interactions of fishy odor compounds to myofibrillar protein were analyzed by HS-GC-MS,and the changes of thermal stability and secondary structure of myofibrillar protein were detected by DSC,UV spectra,fluorescence spectroscopy and Raman spectroscopy.Results indicated that the binding capacity of linear-chain aldehydes to myofibrillar protein increased with the chain length of the aldehydes.Moreover,the presence of these flavour compounds caused the protein structure unfolding,resulting a transition fromα-helix intoβ-sheets andβ-turns,and reduced the fluorescence intensity and thermal stability of the protein.Molecular interactions between aldehyde compounds with myofibrillar protein of grass carp were mainly hydrophobic interactions,and partly of them were hydrogen bonds or ionic bonds.