College of Food Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, PR China.
Ultrason Sonochem. 2013 Jan;20(1):187-95. doi: 10.1016/j.ultsonch.2012.07.011. Epub 2012 Aug 7.
High intensity ultrasonic (HUS, 20 kHz, 400 W) pre-treatments of soybean protein isolate (SPI) improved the water holding capacity (WHC), gel strength and gel firmness (final elastic moduli) of glucono-δ-lactone induced SPI gels (GISG). Sonication time (0, 5, 20, and 40 min) had a significant effect on the above three properties. 20 min HUS-GISG had the highest WHC (95.53 ± 0.25%), gel strength (60.90 ± 2.87 g) and gel firmness (96340Pa), compared with other samples. Moreover, SH groups and non-covalent interactions of GISG also changed after HUS pre-treatments. The HUS GISG had denser and more uniform microstructures than the untreated GISG. Rheological investments showed that the cooling step (reduce the temperature from 95 to 25 °C at a speed of 2 °C/min) was more important for the HUS GISG network formation while the heat preservation step (keep temperature at 95 for 20 min) was more important for the untreated GISG. HUS reduced the particle size of SPI and Pearson correlation test showed that the particle size of SPI dispersions was negatively correlated with WHC, gel strength and gel firmness.
高强度超声（HUS，20 kHz，400 W）预处理大豆分离蛋白（SPI）提高了戊二醛诱导 SPI 凝胶（GISG）的持水力（WHC）、凝胶强度和凝胶硬度（最终弹性模量）。超声时间（0、5、20 和 40 min）对上述三种性质有显著影响。与其他样品相比，20 min 的 HUS-GISG 具有最高的 WHC（95.53±0.25%）、凝胶强度（60.90±2.87 g）和凝胶硬度（96340Pa）。此外，HUS 预处理后 SH 基团和 GISG 的非共价相互作用也发生了变化。HUS-GISG 的微观结构比未处理的 GISG 更致密、更均匀。流变学研究表明，冷却步骤（以 2°C/min 的速度将温度从 95°C 降低到 25°C）对 HUS-GISG 网络形成更为重要，而保温步骤（在 95°C 下保持 20 min）对未处理的 GISG 更为重要。HUS 减小了 SPI 的粒径，Pearson 相关检验表明 SPI 分散体的粒径与 WHC、凝胶强度和凝胶硬度呈负相关。
