加工条件及体外消化对大米低聚肽结构和抗氧化活性的影响  

Effects of Processing Conditions and in Vitro Digestion on the Structure and Antioxidant Activity of Rice Oligopeptides

作　　者：刘文颖 张江涛 王憬 毕园 冯晓文 谷瑞增 侯俊财[3] Liu Wenying;Zhang Jiangtao;Wang Jing;Bi Yuan;Feng Xiaowen;Gu Ruizeng;Hou Juncai(College of Engineering,China Agricultural University,Beijing 100083;Beijing Engineering Research Center of Protein and Functional Peptides,China National Research Institute of Food and Fermentation Industries Co.Ltd.,Beijing 100015;College of Food Science,Northeast Agricultural University,Harbin 150030)

机构地区：[1]中国农业大学工学院,北京100083 [2]中国食品发酵工业研究院有限公司北京市蛋白功能肽工程技术研究中心,北京100015 [3]东北农业大学食品学院,哈尔滨150030

出　　处：《中国食品学报》2022年第7期173-182,共10页Journal of Chinese Institute Of Food Science and Technology

基　　金：“十三五”国家重点研发计划项目(2016YFD0400604);北京市科技创新基地培育与发展工程专项(Z191100002819001)。

摘　　要：通过酶解大米蛋白粉制备大米低聚肽,以分子质量分布、二级结构和氧自由基吸收能力(ORAC)为指标,研究不同温度、pH值和体外消化方式对大米低聚肽结构和抗氧化活性的影响。结果表明:热处理显著降低大米低聚肽在2000~3000 u、3000~5000 u和>5000 u范围内的分子质量(P<0.05),显著提高<150 u的分子质量(P<0.05),然而对重均分子质量、二级结构无显著影响(P>0.05)。40℃下大米低聚肽的ORAC值显著高于其它温度(P<0.05)。pH值对大米低聚肽的重均分子质量、α-螺旋和平行式β-折叠无显著影响(P>0.05)。在pH 6下大米低聚肽的ORAC值显著高于对照组(P<0.05),而pH 2和pH 4的ORAC值显著下降(P<0.05)。体外模拟消化显著降低大米低聚肽在1000~2000 u,2000~3000 u,3000~5000 u,>5000 u范围内的分子质量及重均分子质量(P<0.05),而<150 u所占比例显著升高(P<0.05),而二级结构无显著变化(P>0.05)。先胃蛋白酶后胰蛋白酶消化,可显著提高大米低聚肽的ORAC值(P<0.05)。研究结果表明,大米低聚肽具有一定的结构稳定性和抗氧化活性,为研发抗氧化功能性饮料奠定理论依据。Rice protein powder was used as raw material to prepare rice oligopeptides by two-step enzymatic hydrolysis.The effects of different temperatures,pH values and digestion modes on the structure and antioxidant activity of rice oligopeptides were studied with the molecular weight distribution,secondary structure and oxygen radical absorbance capacity(ORAC)as indicators.The results showed that heat treatment significantly reduced the molecular weight of rice oligopeptides in the range of 2000-3000 u,3000-5000 u and above 5000 u(P<0.05),significantly increased the molecular weight of rice oligopeptides in the range of below 150 u(P<0.05),but had no significant effect on the weight average molecular weight and secondary structure(P<0.05).The ORAC value of rice oligopeptides at 40℃was significantly higher than that at other temperatures(P<0.05).The pH value had no significant effect on the weight average molecular weight,α-helix and parallelβ-pleated sheet of rice oligopeptides(P>0.05).ORAC value of rice oligopeptides at pH 6 was significantly higher than that of the control group(P>0.05),while ORAC values of pH 2 and pH 4 were significantly lower(P<0.05).Simulated digestion in vitro significantly reduced the molecular weight of rice oligopeptides in the range of 1000-2000 u,2000-3000 u,3000-5000 u,above 5000 u and the weight average molecular weight(P>0.05),but the proportion of less than 150 u was significantly increased(P<0.05),but the secondary structure had no significant change(P>0.05).The ORAC value of rice oligopeptides were significantly increased by pepsin digestion plus further trypsin digestion(P<0.05).The above research results show that rice oligopeptides have certain structural stability and antioxidant activity,which lays a theoretical foundation for the development of antioxidant functional beverages.

关 键 词：大米低聚肽 扫描电镜 圆二色光谱 稳定性 结构 抗氧化 

分 类 号：TS210.1[轻工技术与工程—粮食、油脂及植物蛋白工程]