^(60)Co-γ辐照对卵清蛋白糖基化体系结构和糖基化产物的影响

Effect of^(60)Co Gamma Irradiation on the Structure and Glycation Products of Ovalbumin Glycation System

为探究^(60)Co-γ辐照对糖基化体系结构和糖基化产物的影响,以卵清蛋白(OVA)-葡萄糖体系为研究对象,经0,25,50,75,100 kGy的^(60)Co-γ辐照后,采用SDS-PAGE、荧光光谱、圆二色谱测定其分子质量、三级结构及二级结构的变化。借助高效液相色谱法、紫外光谱法测定其体系内产生的有害糖基化产物(果糖胺、丙烯酰胺、荧光性AGEs、戊糖素、类黑精)的含量。OVA分子质量和表面疏水性的增加、内源荧光强度和α-螺旋含量的降低、β-结构(β-折叠和β-转角)含量的增加表明,^(60)Co-γ辐照呈剂量依赖性,促进了OVA与葡萄糖的糖基化反应。此外,^(60)Co-γ辐照后体系内产生的果糖胺、丙烯酰胺的含量呈现先上升后下降的趋势,在辐照剂量为50 kGy时达到最大值。荧光性AGEs、戊糖素、类黑精的含量以剂量依赖性方式增加。综合来看,为了减少辐照加工过程中蛋制品内有害糖基化产物的含量,提高其安全性,需将^(60)Co-γ辐照的剂量控制在25 kGy以内。本研究结果为未来扩展食品辐照技术在蛋制品方面的应用提供一定的科学依据。

In order to explore the effect of^(60)Co gamma irradiation on the structure and glycation products of glycation systems,the ovalbumin(OVA)-glucose system under^(60)Co gamma irradiation at doses of 0,25,50,75 and 100 kGy was regarded as the research object.The molecular weight,tertiary structure,and secondary structure were determined via SDS-PAGE,fluorescence spectroscopy,and far-ultraviolet circular dichroism spectroscopy,respectively.Meanwhile,high performance liquid chromatography and ultraviolet spectrometry were employed to measure the content of detrimental glycation products including fructosamine,acrylamide,fluorescent AGEs,pentosidine,and melanoidin.The results of increased molecular weight,surface hydrophobicity andβ-structure(β-sheet andβ-turn)content and decreased intensity of intrinsic fluorescence emission peak andα-helix content showed that^(60)Co gamma irradiation promoted glycation reaction of OVA in a dose-dependent manner.In addition,the fructosamine and acrylamide in the system during irradiation treatment were increased firstly and then decreased,and the highest contents were presented at 50 kGy.Meanwhile,with the increase of dose,the fluorescent AGEs,pentosidine and melanoidin contents were increased.In short,^(60)Co gamma irradiation dose would be controlled within 25 kGy to reduce detrimental glycation products in egg products and improve their safety during irradiation treatment.This study would provide a scientific proof for expanding the application of food irradiation technology in egg products in the future.