Samaranayake Chaminda P, Sastry Sudhir K
Department of Food, Agricultural and Biological Engineering, The Ohio State University, 590 Woody Hayes Drive, Columbus, OH 43210, United States.
Department of Food, Agricultural and Biological Engineering, The Ohio State University, 590 Woody Hayes Drive, Columbus, OH 43210, United States.
Food Chem. 2016 May 15;199:265-72. doi: 10.1016/j.foodchem.2015.12.010. Epub 2015 Dec 7.
The effect of controlled-frequency moderate electric field treatments on pectin methylesterase and polygalcturonase activities in tomato homogenate was investigated by subjecting identically treated control and electrically-treated samples to the same temperature history. Additionally, a model was developed for the motion of the enzyme molecules subjected to an electric field. Results show that the application of electric fields at a low field strength (0.4V/cm) constant temperature (65°C) has a statistically significant effect on pectin methylesterase activity, typically at or lower than 60 Hz. At higher frequencies, the effects are negligible. Molecular motion simulations suggest that the efficacy at low frequencies may be due to the amplitude of motion being of the order of the intermolecular distance for water. Higher frequencies result in small overall displacements due to rapid reversals in the direction of motion.
通过使经过相同处理的对照样品和电处理样品经历相同的温度历程，研究了可控频率的适度电场处理对番茄匀浆中果胶甲酯酶和多聚半乳糖醛酸酶活性的影响。此外，还建立了一个模型来描述酶分子在电场中的运动。结果表明，在低场强（0.4V/cm）、恒温（65°C）条件下施加电场，对果胶甲酯酶活性具有统计学上的显著影响，通常在60Hz及以下频率时效果明显。在较高频率下，这种影响可以忽略不计。分子运动模拟表明，低频时的效果可能是由于运动幅度与水分子间距离相当。较高频率会导致由于运动方向的快速反转而使整体位移较小。
