酸法脱酰胺对大米蛋白分子间作用力和二级结构的影响  

Intermolecular Forces and Secondary Structure of Acid-deamidated Rice Protein

作　　者：易翠平[1] 姚惠源[2] 

机构地区：[1]长沙理工大学生物与食品工程学院,长沙410076 [2]江南大学食品学院,无锡214036

出　　处：《中国粮油学报》2007年第3期1-4,共4页Journal of the Chinese Cereals and Oils Association

基　　金："十五"重大专项2001BA501A03;校人才引进基金

摘　　要：大米蛋白经酸法脱酰胺改性引起分子间作用力和二级结构发生变化。对改性蛋白表面疏水性、ζ电位、巯基和二硫键、DSC以及FI-IR图谱分析表明,随着脱酰胺度从0增加到69.4%,大米蛋白的表面疏水性从5448.5降低到1433.2,ζ电位从-29.5增大到-52.7。未脱酰胺及低脱酰胺度(6.4%)二硫键含量较高,脱酰胺初期能破坏部分二硫键,当脱酰胺度>19.6%后,脱酰胺对大米蛋白的巯基与二硫键含量不产生影响。随着脱酰胺度增加,蛋白变性的峰值温度降低、热焓增加。此外,酸法脱酰胺对大米蛋白的二级结构有影响,影响结果没有明显变化趋势。The changes of intermolecular forces and secondary structure of the rice protein modified by deamidation with acid were studied. The results of analyzing the surface hydrophobicity, ζ potential, sulfhydryl and disulfide bonds, DSC, and FI - IR spectra of the modified rice protein reveal that the surface hydrophobicity decreases from 5 448.5 to 1 433.2 and ζ potential increases from -29.5 to - 52.7 with the deamidation degree （DAD） of the rice protein raising from zero to 69.4%. Results also show the following trend ： The content of disulfide bond in the original rice protein and the low DAD（6.4% ）rice protein are high. Part of the disulfide bonds is destroyed during the initial deamidation stage. When the DAD 〉 19.6%, the deamidation treatment does not show significant influence on the disulfide bonds. The thermal analysis indicates that the denaturation peak temperature of the protein decreases and the enthalpy increases with the increasing deamidation degree. The FT - IR spectra reveal that the acid - deamidation causes the change of secondary structure of the rice protein in an uncertain manner.

关 键 词：大米蛋白 酸法脱酰胺 分子间作用力 二级结构 

分 类 号：TS210.1[轻工技术与工程—粮食、油脂及植物蛋白工程]