Effect of high-voltage electrostatic field treatments on bananas (Musa paradisiaca var. sapientum) on their postharvest quality, enzymatic activity and morphological changes

Abstract

In this work, the effects of high-voltage electrostatic field (HVEF) on enzyme activities and appearance of stored Musa sapientum were investigated as well as the intensity of spotting by Digital Image Analysis (DIA). By applying HVEF at 6 kV cm−1 during 7.5 minutes, color features on their surface after day 4, maintained stable values (R ≥ 191, G ≥ 165, L* ≥ 82, and b* ≥ 41), while control samples had lower figures of these parameters. Enzyme activities (expressed as Umg protein−1), for pectinmethylesterase in peel, HVEF treatments induced values ≤ 9 Umg−1, while control ≥ 16 Umg−1; polygalacturonase in peel; HVEF samples had activities ≤ 120 Umg−1 at days 6 and 8, while control samples ≥ 211 Umg−1; and, in pulp, after day 4, HVEF brought activities ≤ 37 Umg−1 while control samples were ≥ 71 Umg−1. Polyphenoloxidase, activities for treated samples were enhanced (in the peel, HVEF samples ≥553 Umg −1 and control ones ≤425 Umg−1; and for pulp, HVEF induced activities ≥979 Umg−1 while control ≤717 Umg −1). These results did not impact negatively in the spotting on the surface of the fruits. Results suggested that HVEF can extend the shelf life of M. sapientum.