Effect of high intensity ultrasound on transglutaminase-catalyzed soy protein isolate cold set gel
Effect of high intensity ultrasound on transglutaminase-catalyzed soy protein isolate cold set gel
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高强度超声对转谷氨酰胺酶催化大豆分离蛋白冷凝固凝胶的影响
DOI：
10.1016/j.ultsonch.2015.10.014
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发表时间：
2016
影响因子：
8.4
通讯作者：
Hu Hao
中科院分区：
文献类型：
--
作者：
Zhang Peipei;Hu Tan;Feng Shaolong;Xu Qi;Zheng Ting;Zhou Moxi;Chu Xueqi;Huang Xingjian;Lu Xiaonan;Pan Siyi;Li-Chan Eunice C. Y.;Hu Hao
研究了高强度超声（HIU，105-110 W/cm 2，5或40 min）预处理大豆分离蛋白（SPI）对转谷氨酰胺酶催化的大豆分离蛋白冷凝固凝胶（TSCG）理化性质的影响。大豆分离蛋白经HIU预处理40 min后，TSCG的凝胶强度由34.5 g显著提高到207.1 g。此外，HIU预处理后的凝胶产量和持水力也有所增加。扫描电子显微镜观察表明，大豆分离蛋白的高强度超声处理使TSCG的微观结构更加均匀、致密。HIU TSCG中游离巯基（SH）的含量高于非HIU TSG，尽管在形成TSCG时观察到HIU处理的SPI中存在的SH基团的更大减少，表明二硫键参与凝胶形成。经HIU预处理后，TSCG在变性和非变性溶剂中的溶解度均有所提高，拉曼光谱显示TSCG的疏水氨基酸残基以及多肽骨架构象和二级结构发生了变化。这些结果表明，分子间ε-（γ-谷氨酰基）赖氨酸异肽键、二硫键和疏水相互作用的增加可能有助于HIU TSCG凝胶网络。HIU改变了SPI的理化性质和结构特性，为TGase提供了更好的底物。与非HIU SPI的TSCG相比，SPI分子和聚集体之间的共价和非共价相互作用更大地参与形成所得的TSCG网络结构。
The effects of high intensity ultrasound (HIU, 105–110 W/cm2for 5 or 40 min) pre-treatment of soy protein isolate (SPI) on the physicochemical properties of ensuing transglutaminase-catalyzed soy protein isolate cold set gel (TSCG) were investigated in this study. The gel strength of TSCG increased remarkably from 34.5 to 207.1 g for TSCG produced from SPI with 40 min HIU pre-treatment. Moreover, gel yield and water holding capacity also increased after HIU pre-treatments. Scanning electron microscopy showed that HIU of SPI resulted in a more uniform and denser microstructure of TSCG. The content of free sulfhydryl (SH) groups was higher in HIU TSCG than non-HIU TSG, even though greater decrease of the SH groups present in HIU treated SPI was observed when the TSCG was formed, suggesting the involvement of disulfide bonds in gel formation. Protein solubility of TSCG in both denaturing and non-denaturing solvents was higher after HIU pretreatment, and changes in hydrophobic amino acid residues as well as in polypeptide backbone conformation and secondary structure of TSCG were demonstrated by Raman spectroscopy. These results suggest that increased inter-molecular ε-(γ-glutamyl) lysine isopeptide bonds, disulfide bonds and hydrophobic interactions might have contributed to the HIU TSCG gel network. In conclusion, HIU changed physicochemical and structural properties of SPI, producing better substrates for TGase. The resulting TSCG network structure was formed with greater involvement of covalent and non-covalent interactions between SPI molecules and aggregates than in the TSCG from non-HIU SPI.