丙烯醛对籽瓜种仁蛋白质结构及凝胶特性影响研究

Effects of acrolein on protein structure and gel properties of seed melon seed kernel

籽瓜种仁是富含高脂高蛋白质的坚果种仁,因其高不饱和脂肪酸极易在加工或贮藏过程中发生脂质氧化,对其蛋白质造成一定程度的影响。为探究脂质氧化对蛋白质结构和功能的影响,借助圆二色光谱和质构等技术手段研究脂质氧化产物(丙烯醛)对籽瓜种仁蛋白质的影响。实验结果表明,随着丙烯醛氧化程度加深,籽瓜种仁蛋白质的游离巯基减少,非共价二硫键形成;其二级结构中β-折叠的含量增加,无规则卷曲的含量减少,蛋白质分子粒径增大进而出现聚集现象;且其凝胶特性随着氧化进程的加剧出现变差等现象。研究为籽瓜种仁的加工和贮藏应用提供了良好的技术支撑。

Seed melon seed is a nut seed kernel rich in fat and protein.It is prone for lipid oxidation during processing and storage,because of highly unsaturated fatty acids.The secondary metabolites from lipid oxidation would produce a effect on the protein quality of seed melon kernel.The aim of this study was to investigate the main by-product of lipid peroxidation effect on the structure and functional properties of seed melon protein by using circular dichroism spectroscopy and texture analyzer etc.The experimental results showed that the free sulfhydryl groups of seed melon seed kernel protein were reduced while the acrolein oxidation increased,meanwhile,non-covalent disulfide bonds were formed;the content ofβ-sheets in the secondary structure was increased,and the content of random coils was reduced,also,the particle size of protein molecules increased and the aggregation phenomenon occurred.Furthermore,the gelling property of the seed kernel protein weakened as the oxidation progressed.The research outcomes provide a theoretical basis and technical support for the quality control of seed melon seed kernel protein during processing and storage.