米糠贮藏过程中清蛋白结构变化的研究  

Structural changes of rice bran albumin during storage of rice bran

作　　者：吴伟[1] 蔡勇建[1] 吴晓娟[1] 林亲录[1] 梁盈[1] 

机构地区：[1]中南林业科技大学食品科学与工程学院,稻谷及副产物深加工国家工程实验室,长沙410004

出　　处：《中国油脂》2016年第7期15-19,共5页China Oils and Fats

基　　金：公益性行业(农业)科研专项经费项目(201303071);湖南省教育厅项目(14C1181);湖南省2011协同创新项目(湘教通[2013]448号)

摘　　要：以不同贮藏时间新鲜米糠为原料脱脂制备米糠清蛋白,研究新鲜米糠贮藏时间对米糠清蛋白结构的影响。结果表明:新鲜米糠制备米糠清蛋白的羰基、游离巯基和二硫键含量分别为1.55、46.56、4.01 nmol/mg,随着新鲜米糠贮藏时间的延长,米糠清蛋白的羰基和二硫键含量增加,游离巯基含量下降,新鲜米糠贮藏10 d制备米糠清蛋白的羰基、游离巯基和二硫键含量分别为6.55、29.40、7.87 nmol/mg,表明新鲜米糠贮藏过程中米糠清蛋白发生了氧化;当新鲜米糠贮藏时间从0d增加到10 d,米糠清蛋白粒径从60.18 nm逐渐增加到82.69 nm,溶解性从88.54%逐渐下降到56.00%,表面疏水性指数从789.56逐渐下降到608.97,Zeta电位绝对值从12.26 mV下降到8.83mV,表明蛋白质氧化导致米糠清蛋白形成氧化聚集体;电泳分析表明非二硫共价键参与米糠清蛋白氧化聚集体的形成。Fresh rice bran stored for different periods were used as raw material to prepare rice bran albu- min after defatting, and effects of storage time of fresh rice bran on the structure of rice bran albumin were investigated. The results showed that contents of carbonyl, free sulphydryl and disulfide of rice bran albu- min prepared by fresh rice bran were 1.55,46.56, 4.01 nmolfmg,respectively. Contents of carbonyl and disulfide of rice bran albumin increased, while content of free sulphydryl decreased as storage time of fresh rice bran prolonged. Contents of carbonyl, free sulphydryl and disulfide of rice bran albumin prepared by fresh rice bran with storage time of 10 d were 6.55,29.40,7.87 nmol/mg respectively, indicating that storage of fresh rice bran led to oxidation of rice bran albumin. As storage time of fresh rice bran pro- longed from 0 d to 10 d,particle size of rice bran albumin increased from 60.18 nm to 82.69 nm,while solubility, surface hydrophobicity index and absolute value of Zeta potential of rice bran albumin de- creased from 88.54%, 789.56 and 12.26 mV to 56.00%, 608.97 and 8.83 mV respectively,indicating that protein oxidation led to formation of oxid aggregates of rice bran albumin. Electrophoresis analysis in- dicated that non -disulfide covalent bond participated in the formation of oxid aggregates of rice bran albumin.

关 键 词：米糠 贮藏 米糠清蛋白 蛋白质氧化 聚集 

分 类 号：TS210.9[轻工技术与工程—粮食、油脂及植物蛋白工程]