[Zhang, Yanpeng; Zhang, Weinong; Hu, Zhixiong] College of Food Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, Hubei, China;[Yang, Ruijin] State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China. Electronic address: email@example.com;[Zhao, Wei] State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China
[Yang, Ruijin] Jiangnan Univ, State Key Lab Food Sci & Technol, Wuxi 214122, Jiangsu, Peoples R China.
SPI;soy protein isolate;SFE;steam flash-explosion;HPSEC;high performance size exclusion chromatography;SDS-PAGE;sulfate-polyacrylamide gel electrophoresis;Native-PAGE;Native-polyacrylamide gel electrophoresis;MW;molecular weight;CD;circular dichroism;FI;fluorescence intensity;Steam flash-explosion;Dilute acid soaking;Soybean protein isolate;Structural characterization;Physicochemical properties
The aim of this work was to analyze the influence of steam flash-explosion (SFE) with dilute acid soaking pretreatment on the structural characteristics and physiochemical properties of protein from soybean meal (SBM). The pretreatment led to depolymerisation of soy protein isolate (SPI) and formation of new protein aggregation through non-disulfide covalent bonds, which resulted in broader MW distribution of SPI. The analysis of CD spectroscopy showed that the SFE treatment induced minor changes in secondary structure, however, the intrinsic tryptophan fluorescence revealed that acid soaking and SFE treatment pronouncedly altered the tertiary structure of SPI. The protein zeta potential was shown to be increased after SFE treatment attributed to the changes in protein structure and the covalent coupling between carbohydrate and protein. These results contribute to clarifying the mechanisms of the effect of pretreatment on SPI structure, thus moving further toward implementing SFE in the processing chain of SPI. (C) 2016 Elsevier Ltd. All rights reserved.