School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China.
School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang, Jiangsu 212013, China.
Ultrason Sonochem. 2017 Jul;37:351-359. doi: 10.1016/j.ultsonch.2017.01.034. Epub 2017 Jan 25.
The thermodynamics and kinetics of traditional and simultaneous dual frequency energy-gathered ultrasound (SDFU) assisted enzymolysis of potato protein were investigated to get the knowledge of the mechanisms on the SDFU's promoting efficiency during enzymolysis. The concentration of potato protein hydrolysate and parameters of thermodynamic and kinetic during traditional and SDFU assisted enzymolysis were determined. The results showed that potato protein hydrolysate concentration of SDFU assisted enzymolysis was higher than traditional enzymolysis at the hydrolysis time of 60min (p<0.05) whereas not significantly different at 120min (p>0.05). In some cases, SDFU assisted enzymolysis took less hydrolysis time than traditional enzymolysis when the similar conversion rates of potato protein were obtained. The thermodynamic papameters including the energy of activation (E), enthalpy of activation (△H), entropy of activation (△S) were reduced by ultrasound pretreatment while Gibbs free energy of activation (△G) increased little (1.6%). Also, kinetic papameters including Michaelis constant (K) and catalytic rate constant (k) decreased by ultrasound pretreatment. On the contrary, reaction rate constants (k) of SDFU assisted enzymolysis were higher than that of traditional enzymolysis (p<0.05). It was indicated that the efficiency of SDFU assisted enzymolysis was higher than traditional enzymolysis in a limited time. The higher efficiency of SDFU assisted enzymolysis was related with the decrease of E and K by lowering the energy barrier between ground and active state and increasing affinity between substrate and enzyme.
传统和同时双频能量收集超声（SDFU）辅助酶解土豆蛋白的热力学和动力学研究，以了解 SDFU 在酶解过程中的促进效率的机制。测定了传统和 SDFU 辅助酶解过程中土豆蛋白水解物的浓度以及热力学和动力学参数。结果表明，在水解 60min 时，SDFU 辅助酶解的土豆蛋白水解物浓度高于传统酶解（p<0.05），但在水解 120min 时差异不显著（p>0.05）。在某些情况下，当获得相似的土豆蛋白转化率时，SDFU 辅助酶解比传统酶解需要更少的水解时间。热力学参数，包括活化能（E）、活化焓（△H）、活化熵（△S），通过超声预处理而降低，而活化自由能（△G）增加很少（1.6%）。此外，动力学参数，包括米氏常数（K）和催化速率常数（k），通过超声预处理而降低。相反，SDFU 辅助酶解的反应速率常数（k）高于传统酶解（p<0.05）。这表明在有限的时间内，SDFU 辅助酶解的效率高于传统酶解。SDFU 辅助酶解的高效率与通过降低基态和活性态之间的能垒以及增加底物与酶之间的亲和力而导致的 E 和 K 的降低有关。
