食品科学 ›› 2019, Vol. 40 ›› Issue (17): 14-21.doi: 10.7506/spkx1002-6630-20180925-262

• 基础研究 • 上一篇    下一篇

米糠酸败对米糠蛋白体外胃蛋白酶消化产物结构特征的影响

吴伟,何莉媛,黄慧敏,吴晓娟,林亲录   

  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,湖南?长沙 410004)
  • 出版日期:2019-09-15 发布日期:2019-09-23
  • 基金资助:
    国家自然科学基金面上项目(31771918);国家级大学生创新创业训练平台项目(201810538014); 湖南省大学生研究性学习与创新性实验计划项目(湘教通[2018]255号)

Effect of Rice Bran Rancidity on Structural Characteristics of in Vitro Pepsin Digest of Rice Bran Protein

WU Wei, HE Liyuan, HUANG Huimin, WU Xiaojuan, LIN Qinlu   

  1. (National Engineering Laboratory for Rice and By-product Deep Processing, School of Food Science and Engineering, Central South University of Forestry and Technology, Changsha 410004, China)
  • Online:2019-09-15 Published:2019-09-23

摘要: 将新鲜米糠贮藏不同时间后进行稳定化和脱脂制备米糠蛋白,研究米糠酸败对米糠蛋白体外胃蛋白酶消化产物结构特征的影响。结果表明:随着米糠酸败程度增加,米糠清蛋白亚基、谷蛋白酸性亚基和球蛋白亚基完全被胃蛋白酶消化降解的时间先提前后延迟,而米糠谷蛋白碱性亚基和醇溶蛋白亚基表现为更难被胃蛋白酶消化;分子质量分布和粒径分布结果表明,米糠酸败过程中形成的米糠蛋白氧化聚集体会抑制米糠蛋白体外胃蛋白酶消化;此外,随着米糠酸败程度的增加,米糠蛋白体外胃蛋白酶消化产物内源荧光峰位的红移幅度先增大后减小,表面疏水性则逐渐下降。总之,米糠酸败导致的米糠蛋白氧化对米糠蛋白消化产物的共价交联状态、聚集行为和表面疏水性等结构特征产生了重要影响。

关键词: 米糠酸败, 米糠蛋白, 体外胃蛋白酶消化, 结构特征

Abstract: Rice bran protein was prepared from fresh rice bran subjected to stabilization and defatting after storage for different times with a view to investigating the effect of rice bran rancidity on structural characteristics of its in vitro pepsin digest. The results showed that as the extent of rancidity of rice bran increased, the time required for complete pepsin digestion of albumin subunits, glutelin acidic subunits, and globulin subunits firstly advanced, and then delayed, while glutelin base subunits and prolamin subunits became more difficult to digest by pepsin. The results of molecular mass distribution and particle size distribution indicated that oxidative aggregates of rice bran protein were formed as a result of rancidity, thereby inhibiting its in vitro pepsin digestion. In addition, as the extent of rancidity increased, the pepsin digest exhibited an increase followed by a decrease in the red shift in maximum fluorescence emission wavelength, while the surface hydrophobicity gradually decreased. In conclusion, protein oxidation caused by lipid rancidity in rice bran has important effects on the covalent cross-linking state, aggregation behavior and surface hydrophobicity of in vitro pepsin digest of rice bran protein.

Key words: rice bran rancidity, rice bran protein, in vitro pepsin digestion, structural characteristics

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