College of Food Science and Engineering, Wuhan Polytechnic University, Wuhan 430023, Hubei, China.
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, Jiangsu, China.
Food Chem. 2017 Mar 15;219:48-53. doi: 10.1016/j.foodchem.2016.09.079. Epub 2016 Sep 14.
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.
本工作旨在分析蒸汽闪爆（SFE）与稀酸浸泡预处理对大豆分离蛋白（SPI）结构特性和理化性质的影响。预处理导致大豆蛋白分离物（SPI）解聚，并通过非二硫键共价键形成新的蛋白质聚集，从而导致 SPI 的 MW 分布变宽。圆二色光谱分析表明，SFE 处理仅引起二级结构的微小变化，然而，内源色氨酸荧光表明酸浸泡和 SFE 处理显著改变了 SPI 的三级结构。SFE 处理后，蛋白质 ζ 电位增加，这归因于蛋白质结构的变化和碳水化合物与蛋白质之间的共价结合。这些结果有助于阐明预处理对 SPI 结构影响的机制，从而朝着在 SPI 加工链中实施 SFE 迈进了一步。
