丙二醛氧化修饰对核桃分离蛋白乳化性质的影响  

Effect of Oxidative Modification on the Emulsifying Properties of Protein Isolates of Walnut by Malondialdehyde

作　　者：孙领鸽 毛晓英[1] 王丹丹 吴庆智[1] 朱新荣[1] 万银松[1] Sun Lingge;Mao Xiaoying;Wan Dandan;Wu Qingzhi;Zhu Xinrong;Wan Yinsong(Food College of Shihezi University,Shihezi 832003,Xinjiang)

机构地区：[1]石河子大学食品学院,新疆石河子832003

出　　处：《中国食品学报》2020年第5期84-90,共7页Journal of Chinese Institute Of Food Science and Technology

基　　金：国家自然科学基金项目(31560433);兵团重点领域科技攻关计划项目(2018AB015)。

摘　　要：以不同浓度(0~10 mmol/L)的丙二醛氧化处理的核桃分离蛋白为研究对象,探究脂肪氧合酶(LOX)诱导多不饱和脂肪酸发生脂质过氧化反应过程中产生的活性醛类对核桃分离蛋白乳化性质的影响。研究结果表明:随着丙二醛浓度从0增至10 mmol/L,核桃分离蛋白发生显著氧化,羰基值从3.12 nmol/mg增至20.61 nmol/mg;表面疏水性呈现先上升后下降的趋势;乳液内源荧光强从419.97降至109.86,最大吸收波长λmax发生蓝移;乳液粒径和乳析率均呈现先减小后增大的趋势;乳液Zeta电位值和乳化稳定性则呈现先增加后减小的趋势;而乳化活性从46.57 m^2/g降至26.26 m^2/g。当丙二醛浓度为0.1 mmol/L时,核桃分离蛋白乳液粒径和乳析率达到最小值,Zeta电位值和乳化稳定性达到最大值,说明适度的丙二醛氧化使得核桃分离蛋白的乳液更加稳定,而氧化对蛋白质乳化活性产生负面影响。Malondialdehyde was selected as a representative of reactive aldehydes produced in the process of polyunsaturated fatty acids lipid peroxidation catalyzed by lipoxygenase,and the aim of this work was to investigate the effect of malondialdehyde oxidation on the emulsifying properties of walnut protein isolates.The results indicated that as concentration of malondialdehyde increased from 0 to 10 mmol/L,carbonyl content of walnut protein isolates increased from 3.12 nmol/mg to 20.61 nmol/mg;Surface hydrophobicity(H0)showed the trend of first increase and then decrease(P<0.05);Intrinsic fluorescence of emulsion decreased from 419.97 to 109.86 and maximum emission wavelength moved in the short wave direction;Droplet size distributions and creaming rate firstly decreased then increased;Zeta potential and emulsion stability of the test emulsions firstly increased then decreased;but emulsifying activity decreased form 46.57 m^2/g to 26.26 m^2/g.When malondialdehyde concentration was 0.1 mmol/L,droplet size distributions and creaming rate reached the minimum value;and zeta potential and emulsion stability reached the maximum value.The analysis of the results showed lower level oxidation could generate emulsion stability of walnut protein isolates,while higher level oxidation had a negative effect on the emulsifying properties.

关 键 词：丙二醛 蛋白氧化 核桃 乳化性 粒径分布 

分 类 号：TS201.21[轻工技术与工程—食品科学]