碱与热处理对大米蛋白质结构与功能性质的影响  

Effects of pH and heat treatments on structure and functional properties of rice proteins

作　　者：刘芳[1] 许宙[1] 陈茂龙[1] 程云辉[1] LIU Fang, XU Zhou, CHEN Mao-long ,CHENG Yun-hui(College of Chemical and Biological Engineering, Changsha University of Science and Technology, Changsha, Hunan 410114, China)

机构地区：[1]长沙理工大学化学与生物工程学院,湖南长沙410114

出　　处：《食品与机械》2018年第8期10-15,共6页Food and Machinery

基　　金：国家自然科学基金项目(编号:31771901)

摘　　要：以大米蛋白质为原料,研究碱处理和热处理对大米蛋白质结构与功能性质的影响。研究结果发现:经不同pH处理40 min后,大米蛋白质功能性质均有一定程度改善,其中经pH 12. 0/40 min处理的大米蛋白质溶解性、乳化性与乳化稳定性、起泡性分别提高了2. 46,2. 85,1. 12,2. 51倍;同时,> 100 kDa的组分含量减少,此时蛋白质分子中的α-螺旋、β-转角含量分别减少了26. 99%,10. 54%,而β-折叠、无规卷曲含量分别增加了14. 65%,20. 23%。采用50~90℃/40 min的条件对大米蛋白质进行热处理,其结构性质和溶解性、表面疏水性皆无明显变化;但乳化性与乳化稳定性、起泡性则随着热处理温度升高而提高,90℃热处理可达到最大值,分别是原大米蛋白质的2. 41,1. 09,1. 62倍。结果表明经单独碱处理、热处理后,大米蛋白质的结构发生了改变,但溶解度改善效果不明显。In this study,rice protein was used as raw material to study the effect of pH treatment and heat treatment on the structure and functional properties of rice protein. Studies have found that the functional properties of rice proteins have been improved to some extent after being treated with different pH values for 40 minutes. The solubility,emulsifying and emulsifying stability,foaming property and surface hydrophobicity of RP treated at pH 12. 0/40 min were 5. 16%,0. 626% and 12. 64%,and 135%,respectively,with 2. 46,2. 85,1. 12,and 2. 51 times higher than that of the RP. At this time,the fraction of 〉100 kDa was reduced,the content of α-helix and β-turn in protein molecules decreased by 26.99% and 10. 54%,respectively,while the β-sheets and random coil were increased by 14. 65% and 20. 23%. Heat treatment with only 50 - 90℃/40 min conditions showed no significant changes in the structure,solubility,and surface hydrophobicity; however,the emulsifying,emulsifica-tion stability,and foaming property increased as the temperature increased,and the maximum values were obtained at 90 ℃,which were 2.41,1. 09,and 1. 62 times that of the untreated rice protein,respectively.The results showed that the structure of rice protein changed after alkali treatment and heat treatment,but the solubility improvement effect was not obvious.

关 键 词：大米蛋白质 碱溶性谷蛋白 碱处理 热处理 结构 功能性质 

分 类 号：TS201.21[轻工技术与工程—食品科学]