食品科学

• 基础研究 • 上一篇    下一篇

芋艿分离蛋白质的流变特性

王教飞1,2,黄友如1,*,钱雅萍1,赵 琳1,陈 茵1   

  1. 1.常熟理工学院生物与食品工程学院,江苏 常熟 215500;2.中国矿业大学化工学院,江苏 徐州 221116
  • 出版日期:2015-05-15 发布日期:2015-05-11

Rheological Properties of Taro Protein Isolate

WANG Jiaofei1,2, HUANG Youru1,*, QIAN Yaping1, ZHAO Lin1, CHEN Yin1   

  1. 1. School of Biotechnology and Food Engineering, Changshu Institute of Technology, Changshu 215500, China;
    2. School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, China
  • Online:2015-05-15 Published:2015-05-11

摘要:

以芋艿分离蛋白为材料,研究了不同pH值环境条件下芋艿分离蛋白的流变特性、紫外和荧光光谱。结果表明:pH值环境对芋艿蛋白的变性及聚集有明显的影响。在pH值接近芋艿蛋白的等电点时,芋艿分离蛋白因聚集导致其表观黏度较高,滞后现象明显,胶凝点温度(Tgel)及凝胶储能模量(G’)较高;当pH值升高至8.0时(大于芋艿蛋白的等电点),芋艿分离蛋白解聚集,构象展开,表观黏度较低,滞后现象减弱,Tgel及凝胶G’降低。随溶液pH值的升高,频率扫描曲线G’与损耗模量(G”)的交点逐渐向高频方向移动并最终消失。在pH 7.0时,芋艿分离蛋白的紫外吸收峰位于284 nm波长处;其荧光光谱最大激发波长为289.7 nm,最大发射波长为330.3 nm。

关键词: 芋艿分离蛋白, 流变, 紫外, 荧光, 等电点

Abstract:

Taro protein isolate was studied for its rheological properties and characterized by ultraviolet and fluorescence
spectroscopy at different pH conditions. The results showed that pH had an obvious effect on denaturation and aggregation
of taro protein isolate. At pH values close to the isoelectric point, taro protein isolate aggregates had higher apparent
viscosity, obvious hysteresis, and higher gelling temperature (Tgel) and gel storage modulus (G’). At pH 8.0 (greater than
taro proteins isoelectric point), disaggregation, conformational unfolding, lower apparent viscosity, reduced hysteresis, and
decreased Tgel and gel G’ of taro protein isolate were observed. Along with an increase in solution pH, intersection of G’ and
G” was shifted in the high frequency direction and disappear gradually. At pH 7.0, the ultraviolet absorption peak occurred
at 284 nm, and the maximum fluorescence excitation and emission wavelengths were 289.7 nm and 330.3 nm, respectively.

Key words: taro protein isolate, rheology, ultraviolet, fluorescence, isoelectric point

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