Combined effect of high hydrostatic pressure and mild heat treatments on pectin methylesterase (PME) inactivation in comminuted orange.

Background: Comminuted orange, a product obtained by grinding the juice and peel and used to formulate beverages, has a high pectin methylesterase (PME) activity; thus the inactivation of this enzyme is necessary to avoid quality losses related to cloud loss. The use of high hydrostatic pressure (HHP) and mild temperature allows inactivation of enzymes with minimal quality changes. This work aimed to evaluate the effect of pressure, mild temperature and time of treatment, including come-up and holding time, on the inactivation of PME in comminuted orange, and to apply kinetic and response surface models (RSM) to predict residual PME activity (A/A0 ).