标题：Optimization of Combined Pulsed Electric Fields and Mild Temperature Processing Conditions for Red Apple Juice Polyphenol Oxidase and Peroxidase Inactivation
期刊名称：Advance Journal of Food Science and Technology
印刷版ISSN：2042-4868
电子版ISSN：2042-4876
出版年度：2014
卷号：6
期号：5
页码：638-646
出版社：MAXWELL Science Publication
摘要：The effect on Polyphenol Oxidase (PPO) and Peroxidase (POD) enzyme activity in red apple juice was evaluated after combined Pulsed Electric Fields (PEF) and mild temperature processing using a response surface methodology. Changes in color were also analyzed and compared with thermally treated and unpasteurized juices. The studied factors were electric field strength (10-30 kV/cm), treatment time (200-1000 µs) and temperature (20-60°C). A significant second-order response function covering the whole range of experimental conditions was obtained for each enzyme. Treatments conducted at 30 kV/cm, 1000 µs and 60°C led to red apple juice with the lowest residual enzyme activity (0.04 and 0.16 for PPO and POD, respectively). Overall change in color was significantly lower (p<0.05), in comparison with severe thermal treatments. It was feasible to achieve comparable enzyme inactivation and better preserve natural juice color by this hurdle technique.
关键词：Color ; combined PEF and mild temperature ; peroxidase ; polyphenol oxidase ; red apple juice ; response surface methodology ;
