Influence of moderate electric field on inactivation kinetics of peroxidase and polyphenol oxidase and on phenolic compounds of sugarcane juice treated by ohmic heating

摘要

This study investigated the non-thermal effects of electricity on enzymatic inactivation kinetics of peroxidase and polyphenol oxidase and on degradation of total phenolic and total flavonoid compounds during ohmic heating of sugarcane juice. A kinetic modeling was carried out from the adjustment of various models applicable to enzyme inactivation, and the Weibull distribution model was the most suitable to describe the inactivation of peroxidase. The presence of an electric field With low intensity significantly influenced the biochemical reactions occurred during peroxidase activation at 60 degrees C and inactivation at 80 degrees C. Polyphenol oxidase, a more thermolabile enzyme, was almost totally inactivated before reaching the target temperature (holding phase) of the experiments. The maximum total phenolic and total flavonoid degradation were approximately 23 and 39%, respectively. Statistical analyses showed no differences between conventional and ohmic heating for total phenolic and total flavonoid compounds. (C) 2016 Elsevier Ltd. All rights reserved.