{"title":"Modification of soybean protein isolate by pH-shifting combined with ultrasonic treatment: Structural, viscosity, and functional properties","authors":"Zimeng Kang, Shuang Zhang , Yue Kong, Zenan Wu, Yanhui Li, Tianyi Liu, Fengying Xie","doi":"10.1016/j.foostr.2024.100383","DOIUrl":null,"url":null,"abstract":"<div><p>In order to reduce the viscosity of soybean protein isolate (SPI) and improve its processing suitability, this study investigated the impact of pH-shifting and ultrasonic treatments on the structure, viscosity and functional properties of SPI. The results indicated that both without and with ultrasonication, the pH-shifting, especially the treatment of alkaline pH-shifting decreased α-helix and β-sheet contents and particle size of SPI, while increased its β-turn and random coil contents, fluorescence intensity, surface hydrophobicity and free sulfhydryl content. The alkaline pH-shifting combined with ultrasonic treatments reduced the viscosity of SPI from 98.97 mPa.s to 22.83 mPa.s. These structural changes endowed SPI with higher solubility (from 81.13 % to 91.53 %), and better emulsifying and foaming properties. Moreover, principal component analysis (PCA) was employed to visualise the influences of pH-shifting and ultrasonic treatments on SPI, confirmed that the structural changes of SPI were correlated with its viscosity and functional properties. These results have important implications for promoting the application of SPI in fluid food.</p></div>","PeriodicalId":48640,"journal":{"name":"Food Structure-Netherlands","volume":"42 ","pages":"Article 100383"},"PeriodicalIF":5.6000,"publicationDate":"2024-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Food Structure-Netherlands","FirstCategoryId":"97","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2213329124000194","RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"FOOD SCIENCE & TECHNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
In order to reduce the viscosity of soybean protein isolate (SPI) and improve its processing suitability, this study investigated the impact of pH-shifting and ultrasonic treatments on the structure, viscosity and functional properties of SPI. The results indicated that both without and with ultrasonication, the pH-shifting, especially the treatment of alkaline pH-shifting decreased α-helix and β-sheet contents and particle size of SPI, while increased its β-turn and random coil contents, fluorescence intensity, surface hydrophobicity and free sulfhydryl content. The alkaline pH-shifting combined with ultrasonic treatments reduced the viscosity of SPI from 98.97 mPa.s to 22.83 mPa.s. These structural changes endowed SPI with higher solubility (from 81.13 % to 91.53 %), and better emulsifying and foaming properties. Moreover, principal component analysis (PCA) was employed to visualise the influences of pH-shifting and ultrasonic treatments on SPI, confirmed that the structural changes of SPI were correlated with its viscosity and functional properties. These results have important implications for promoting the application of SPI in fluid food.
期刊介绍:
Food Structure is the premier international forum devoted to the publication of high-quality original research on food structure. The focus of this journal is on food structure in the context of its relationship with molecular composition, processing and macroscopic properties (e.g., shelf stability, sensory properties, etc.). Manuscripts that only report qualitative findings and micrographs and that lack sound hypothesis-driven, quantitative structure-function research are not accepted. Significance of the research findings for the food science community and/or industry must also be highlighted.