羟基自由基氧化对乳清蛋白疏水性的影响  

Effects of Hydroxyl Radical Induced Oxidation on Hydrophobicity of Whey Protein Isolate

作　　者：崔旭海[1] 孔保华[2] 

机构地区：[1]枣庄学院生命科学系,山东枣庄277160 [2]东北农业大学食品学院,黑龙江哈尔滨150030

出　　处：《食品科学》2009年第13期33-36,共4页Food Science

基　　金：国家自然科学基金项目(30871818);黑龙江省自然科学基金重点项目(ZJN0605-01)

摘　　要：本实验研究在羟基自由基氧化体系中,不同的H2O2浓度(1～20mmol/L)、FeCl3浓度(0.1～2mmol/L)以及不同的pH值、温度、盐浓度等环境条件对乳清蛋白疏水性的影响,每种氧化条件的氧化时间分别为1、3、5h。结果表明,氧化和环境因素对乳清蛋白的疏水性影响很大,在H2O2体系中当H2O2浓度为5mmol/L时疏水值达到最大,为9559.2,是对照组的4.88倍,明显高于FeCl3体系中的变化;疏水性在偏离等电点pH7.0时较大,在适宜的温度和盐浓度下能够增加乳清蛋白的疏水性。说明氧化过程中,乳清蛋白的疏水性受H2O2浓度的改变影响最大,并且也受其他环境条件的影响。The objective of the present study was to investigate the effects of different pH values, temperatures, NaCl concentrations on hydrophobicity of whey protein isolate （WPI） exposed to hydroxyl radical-generating systems （HRGS） with different concentrations of H2O2 （1- 20 mmol/L） or FeCh （0.1- 2 mmol/L） for 1, 3 and 5 h. The results showed that the hydrophobicity of WPI was significantly influenced by oxidation and various environmental conditions. The maximal hydrophobicity of WPI was 9559.2 when exposed to 5 mmol/L H2O2-0.1 mmol/L FeCl3-0.1 mmol/L ascorbic acid system, which was 4.88 times that of the control and obviously higher than that of WPI exposed to HRGS systems with different concentrations of FeCl3. The hydrophobicity was high at pH values far away from pI 7.0 and was enhanced by the optimal temperature and NaCl concentration. These results suggest that the hydrophobicity of WPI is significantly affected by H2O2 concentration as well as environmental conditions during the oxidation process.

关 键 词：羟基自由基 氧化 乳清蛋白 疏水性 

分 类 号：TS201.3[轻工技术与工程—食品科学]