自由基引起的氧化对牛乳清蛋白凝胶特性的影响  

Effects of protein oxidation by a free radical-generating system on gel characteristics of bovine whey protein

作　　者：崔旭海[1,2] 孔保华[1] 

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

出　　处：《农业工程学报》2009年第S1期222-227,共6页Transactions of the Chinese Society of Agricultural Engineering

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

摘　　要：为了深入了解蛋白氧化对凝胶特性的影响,以此探讨乳清蛋白氧化对其功能性质的影响机制,该文主要研究了氧化对乳清蛋白凝胶质地、流变学特性和微观结构变化的影响。试验采用羟基自由基氧化体系,在不同H2O2浓度(1～20mmol/L)及不同FeCl3浓度(0.1～1mmol/L)对乳清蛋白分别氧化3h,通过质构仪、流变仪和扫描电镜对凝胶特性和微观结构进行研究。结果显示:同未氧化乳清蛋白相比,在所有氧化条件下,凝胶硬度降低了90%以上,贮藏模量(G')值降低了17%以上,复合模量(G*)值降低了20%以上;高浓度氧化条件下,弹性降低了20%以上。氧化明显改变了凝胶的微观结构,随着氧化剂的加入,导致了疏松多孔且不规则凝胶的形成。上述结果表明,氧化对蛋白凝胶质地和凝胶形成能力起着很大的破坏作用,并影响着其微观结构。In order to understand the effects of protein oxidation on gels properties and investigate the mechanism of the changes of protein functionality,gel texture,rheological properties and gel microstructure were studied in this paper. Whey protein isolate(WPI)was exposed to a hydroxyl radical-generating system(HRGS)under different concentrations of H2O2(1-20 mmol/L)or FeCl3(0.1-1 mmol/L)for 3 h.The results revealed that the hardness of gel decreased by more than 90%,the storage modulus(G'value)decreased by more than 17%,and the complex modulus(G*value)decreased by more than 20%in all oxidative conditions compared with those of nonoxidized protein gels.The gel springiness decreased by more than 20%in a higher concentration of prooxidants.And gel microstructure was greatly changed by protein oxidation,a kind of loose,porous and irregular gel was formed with the addition of oxidants.These experiments suggested that oxidation caused great damages to the gel texture and the gel formation ability of WPI,and also affected the changes of gel microstructure.

关 键 词：蛋白氧化 乳清蛋白 凝胶特性 流变性质 微观结构 

分 类 号：TS201.2[轻工技术与工程—食品科学]