脂肪氧合酶催化亚油酸氧化对核桃蛋白的影响  

Impacts of linoleic acid oxidation catalyzed by lipoxygenase on walnut protein

作　　者：王旭敏 李怡霞 邓子雨 张杨杰 狄建兵[1] Wang Xumin;Li Yixia;Deng Ziyu;Zhang Yangjie;Di Jianbing(Shanxi Agricultural University College Of Food Science And Engineering,Taigu 030801,China;Huashuo(Shanxi)Green Industry Development Group Biotechnology Testing Co.,Ltd.,Shuozhou 038300,China;Shanxi Agricultural University Shanxi Functional Agricultural Products Inspection And Testing Center,Taiyuan 030031,China;Taizhou Anjing Food Co.,Ltd.,Tai-zhou 225700,China)

机构地区：[1]山西农业大学食品科学与工程学院,山西晋中030801 [2]华朔(山西)绿色产业发展集团生物科技检测有限公司,山西朔州038300 [3]山西农业大学山西功能农产品检验检测中心,山西太原030031 [4]泰州安井食品有限公司,江苏泰州225700

出　　处：《山西农业大学学报（自然科学版）》2023年第4期120-128,共9页Journal of Shanxi Agricultural University(Natural Science Edition)

基　　金：山西农谷建设科研专项资助项目(SXNGJSKYZX201906)。

摘　　要：[目的]为了抑制核桃蛋白的氧化、提高核桃蛋白的综合利用率、增加核桃产品的货架期,本文研究了蛋白质氧化对核桃蛋白结构的影响。[方法]采用脂肪氧合酶催化不同添加量的亚油酸氧化形成的反应系统,亚油酸添加量分别为0、3、4.5、7.5、9 mL,对核桃蛋白进行不同程度的氧化修饰,对核桃氧化蛋白的溶解度、粒径、电位、巯基含量、表面疏水性、二级结构以及内源荧光进行检测分析。[结果]随着亚油酸的增加,Zeta电位绝对值与表面疏水性均呈现先增加后减小的趋势,在亚油酸添加量为3 mL时达到最大,Zeta电位绝对值为16.73 mV,疏水指数为52.33。当亚油酸添加量为0~3 mL时,溶解度降低,粒径变小,当亚油酸添加量大于4.5 mL,溶解度回升,并且在4.5 mL时达到峰值45.81%,粒径向粒度大的方向偏移,亚油酸添加量为9 mL时,核桃氧化蛋白溶解性开始降低,粒径开始向粒度小的方向偏移。随着体系中亚油酸添加量的增加,游离巯基含量呈下降趋势,从75.58μmol·g^(-1)下降到41.90μmol·g^(-1);当亚油酸添加量大于4.5 mL时,二级结构的酰胺Ⅰ带峰位开始向低波长处移动,转移到1654 cm-1处;内源荧光最大吸收波长先增大后减小,荧光强度持续降低,从155.35降低到115.10。[结论]脂肪氧合酶催化亚油酸氧化会使得核桃蛋白结构发生变化,较低程度的氧化有利于改善核桃的蛋白结构性质。[Objective]In order to inhibit the oxidation of walnut protein,improve the comprehensive utilization rate of walnut protein,and extend the shelf life of walnut products,this study investigated the influence of protein oxidation on the structure of walnut protein.[Methods]Different levels of oxidation modification were carried out on walnut protein using a reaction system formed by lipoxygenase catalyzed oxidation of linoleic acid at various added amounts(0,3,4.5,7.5,and 9 mL).The solubility,particle size,zeta potential,sulfhydryl content,surface hydrophobicity,secondary structure,and intrinsic fluorescence of walnut oxidized protein were detected and analyzed.[Results]With the increase of linoleic acid,both the absolute value of Zeta potential and hydrophobicity showed an increasing trend followed by a decrease.The maximum values were reached at an addition of 3 mL of linoleic acid,with a Zeta potential absolute value of 16.73 mV and the hydrophobicity index of 52.33.When the added amount of linoleic acid was 0 to 3 mL,the solubility decreased and particle size became smaller.When the added amount of linoleic acid exceeded 4.5 mL,the solubility increased again,peaking at 45.81%at 4.5 mL,and the particle size shifted towards larger size.At 9 mL of linoleic acid addition,the solubility of oxidized walnut protein began to decrease,and the particle size shifted towards smaller sizes.With the increase of linoleic acid content in the system,the content of free sulfhydryl content decreased from 75.58 to 41.90μmol·g^(-1).When the added amount of linoleic acid was greater than 4.5 mL,the peak position of the amide I band in the secondary structure shifted to lower wavelength,moving to 1654 cm-1.The maximum absorption wavelength of intrinsic fluorescence first increased and then decreased,with a continuous decrease in fluorescence intensity from 155.35 to 115.10.[Conclusion]Lipoxygenase-catalyzed oxidation of linoleic acid leads to changes in the structure of walnut protein,and mild oxidation is conducive to improving th

关 键 词：核桃氧化蛋白 脂肪氧合酶 亚油酸 氧化修饰 

分 类 号：TS201.21[轻工技术与工程—食品科学]