Application of pulsed electric field to promote peelability on peponids and drupes: Understanding the effects on cells and the physical properties of fruits

Abstract

Pulsed Electric Field (PEF) technology is a non-thermal food processing method gaining attention for its applications in treating fruits and vegetables, particularly for improving peeling efficiency. This study evaluated the effect of PEF on the peeling performance, colour, texture and structural changes in mango and red bell peppers. Blanching at 94 °C (1 and 3 min for mangoes and 1 and 2 min for red bell peppers) was used to compare the effectiveness of traditional peeling methods with PEF treatments, which were applied at 1 kV/cm with energy levels of 1.1 and 4.6 kJ/kg for mangoes and 3.4 and 10.3 kJ/kg for red bell peppers. The results showed that mangoes PEF-treated at 4.6 kJ/kg reduced peeling force by 50 % and peeling loss by 40 %, outperforming blanching (3 min), which achieved a similar reduction in peeling force and a 30 % reduction in peeling loss. Microstructural analysis revealed cell wall modifications and changes in collenchyma and parenchyma, contributing to improved peeling in mangoes. However, PEF did not improve red bell pepper peeling, while blanching for 2 min reduced firmness by 50 %, resulting in cell shrinkage and thicker walls. Furthermore, PEF better preserved the colour of both fruits compared to blanching, which caused more significant colour changes. This finding demonstrates that PEF treatment is an effective peeling method for mangoes, preserving their quality. However, its application is less effective for red bell peppers, likely due to variations in tissue structure and morphological characteristics.