Optimization of multiple linear regression modeling for reducing peroxidase activity in carrots using pulse electric fields

Peroxidase enzyme (POD) significantly impacts the processing of fruits and vegetables because it can cause unfavorable color, texture and flavor changes. Pulsed electric field (PEF) treatment is an emerging non-thermal technology that can affect enzyme activity while preserving food quality. This study aimed to model and optimize the PEF processing parameters on POD activity of carrot, specifically the number of pulses, electric field strength, relative orientation of carrot fiber and electric field direction (parallel and perpendicular), and the post-treatment time. The statistical analysis of the experimental data showed that the sample orientation, the post-treatment time, and their interaction with the electric field strength applied significantly affected the reduction of POD activity. The Multiple Linear Regression modelling of the experimental data permitted an accurate description of the influence of process conditions on POD activity and the optimization of the process. Thus, the greater POD reduction was observed after 45 min of a PEF treatment of 12 pulses of 0.6 kV cm –1 with carrot samples' fibers parallel to the electric field direction. This model can be employed to identify the treatment conditions that maximize activity reduction in future studies.