摘要
通过研究大豆7S及11S蛋白的结构、理化性质与凝胶性,进而研究三者之间的关系。采用傅里叶变换红外光谱、Gauss分峰拟合对蛋白质的二级结构进行研究;利用ANS荧光探针法,Ellman试剂法和Zeta电位仪对大豆7S及11S蛋白的表面疏水性、巯基含量及粒径进行测定;通过质构仪对蛋白凝胶的硬度,胶黏性及弹性进行分析。结果表明,蛋白质的表面疏水性随α-螺旋、β-折叠相对含量的增大而减小,随β-转角和无规卷曲相对含量的增大而增大。表面疏水性越大越利于凝胶网络的形成。大豆7S蛋白凝胶形成的最优条件为蛋白质量浓度0.12 g/mL、温度90℃、pH 6~8、Na+质量浓度0.002 g/mL;大豆11S蛋白凝胶形成的最优条件为蛋白质量浓度0.12 g/mL、温度95℃、pH 8~9、Na+质量浓度0.002 g/mL。蛋白质的二级结构决定了蛋白质的表面疏水性,而表面疏水性影响了凝胶的形成,同时凝胶形成的外在因素又影响着蛋白的表面疏水性。
The present study aimed to investigate the relationship between the structural,physicochemical and gelation properties of soybean 7S and 11S proteins.The secondary structures were explored by Fourier transform infrared(FT-IR)spectroscopy with Gaussian peak fitting.The fluorescent probe 1-anilino-naphthalene-8-sulfonate(ANS),Ellman’s reagent and a zeta potential meter were used to determine the surface hydrophobicity,sulfhydryl content and particle size of the proteins,respectively.The hardness,gumminess and springiness of the protein gels were analyzed with a texture analyzer.The results showed that the surface hydrophobicity decreased with increasing proportions ofα-helix andβ-sheet,but increased with increasing proportions of random coil andβ-turn.Higher surface hydrophobicity was advantageous to the formation of gel network.The optimal gelation conditions for soybean 7S protein were determined as follows:protein concentration 0.12 g/mL,temperature 90℃,pH 68;and Na+concentration 0.002 g/mL;and for 11S soybean:protein concentration 0.12 g/mL,temperature 95℃,pH 89,and Na+concentration 0.002 g/mL.The secondary structures of the proteins determined their surface hydrophobicity,while the surface hydrophobicity affected the formation of gels.Meanwhile,the external factors of gel formation also affected the surface hydrophobicity of the proteins.
作者
冯芳
刘文豪
陈志刚
FENG Fang;LIU Wenhao;CHEN Zhigang(College of Food Science and Technology,Nanjing Agricultural University,Nanjing 210095,China;Henan Xiangshang Food Co.Ltd.,Hebi 456250,China)
出处
《食品科学》
EI
CAS
CSCD
北大核心
2020年第2期58-64,共7页
Food Science
基金
江苏省优势学科基金项目(080-80900233)
江苏省紫菜产业技术体系项目(080-600650)
关键词
大豆7S蛋白
大豆11S蛋白
二级结构
巯基
表面疏水性
凝胶性
soybean 7S protein
soybean 11S protein
secondary structure
sulfhydryl
surface hydrophobicity
gelation properties
作者简介
第一作者:冯芳(1993-)(ORCID:0000-0002-8076-059X),女,硕士研究生,研究方向为农产品加工,E-mail:2016108009@njau.edu.cn;通信作者:陈志刚(1971-)(ORCID:0000-0002-8911-4295),男,教授,博士,研究方向为食品生物技术,E-mail:zgchen@njau.edu.cn。
