{"title":"Production of protein-epigallocatechin gallate conjugates using free radicals induced by ultrasound and their gelation behavior","authors":"","doi":"10.1016/j.foodchem.2024.141300","DOIUrl":null,"url":null,"abstract":"<div><p>In this study, free radicals generated by ultrasound were used to prepare conjugates of food proteins (soybean protein isolates, sodium caseinate and gelatin) with epigallocatechin gallate (EGCG). The changes in free amino and sulfhydryl group contents were used to confirm the occurrence of conjugation. The formation of covalent interactions on surface hydrophobicity, functional groups, structures, thermal stability, and gelation behavior of three proteins were investigated. The results showed that conjugation led to decrease in free amino and sulfhydryl group contents, reduction in the intensity of amide A and fluorescence intensity, and increase in β-fold content. The conjugation also resulted in a decrease in surface hydrophobicity and thermal stability of soybean protein isolates and sodium caseinate, but an increase in the surface hydrophobicity and thermal stability of gelatin. Furthermore, the covalent bonding between proteins and EGCG improved gel strength, water holding capacity, and resulted in a denser and more compact microstructure.</p></div>","PeriodicalId":318,"journal":{"name":"Food Chemistry","volume":null,"pages":null},"PeriodicalIF":8.5000,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Food Chemistry","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0308814624029509","RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, APPLIED","Score":null,"Total":0}
引用次数: 0
Abstract
In this study, free radicals generated by ultrasound were used to prepare conjugates of food proteins (soybean protein isolates, sodium caseinate and gelatin) with epigallocatechin gallate (EGCG). The changes in free amino and sulfhydryl group contents were used to confirm the occurrence of conjugation. The formation of covalent interactions on surface hydrophobicity, functional groups, structures, thermal stability, and gelation behavior of three proteins were investigated. The results showed that conjugation led to decrease in free amino and sulfhydryl group contents, reduction in the intensity of amide A and fluorescence intensity, and increase in β-fold content. The conjugation also resulted in a decrease in surface hydrophobicity and thermal stability of soybean protein isolates and sodium caseinate, but an increase in the surface hydrophobicity and thermal stability of gelatin. Furthermore, the covalent bonding between proteins and EGCG improved gel strength, water holding capacity, and resulted in a denser and more compact microstructure.
本研究利用超声波产生的自由基制备表没食子儿茶素没食子酸酯(EGCG)与食品蛋白质(大豆分离蛋白、酪蛋白酸钠和明胶)的共轭物。游离氨基和巯基含量的变化被用来证实共轭作用的发生。研究了共价相互作用对三种蛋白质表面疏水性、官能团、结构、热稳定性和凝胶行为的影响。结果表明,共轭作用导致游离氨基和巯基含量减少,酰胺 A 强度和荧光强度降低,β-倍含量增加。共轭还导致大豆分离蛋白和酪蛋白酸钠的表面疏水性和热稳定性降低,但明胶的表面疏水性和热稳定性提高。此外,蛋白质与 EGCG 之间的共价键合提高了凝胶强度和持水能力,并使微观结构更致密、更紧凑。
期刊介绍:
Food Chemistry publishes original research papers dealing with the advancement of the chemistry and biochemistry of foods or the analytical methods/ approach used. All papers should focus on the novelty of the research carried out.