Low-voltage electrostatic field delays postharvest softening of ‘France’ prune by inhibiting cell wall degradation

This study investigated the efficacy of low-voltage electrostatic field (LVEF) treatment in delaying postharvest softening of ‘France’ prune during 60-day storage at 0 ± 0.5 °C. The results indicated that LVEF application significantly preserved fruit quality parameters compared to the control (CK), demonstrating enhanced maintenance of firmness, total soluble solids, and titratable acidity, along with reduced weight loss. Biochemical analyses revealed that LVEF treatment effectively inhibited the activities of key cell wall-degrading enzymes, including pectinase, polygalacturonase, cellulase, β-galactosidase, and α-L-Arabinofuranosidase. Concurrently, LVEF preserved structural polysaccharides, as evidenced by higher retention of water-insoluble pectin, cellulose, hemicellulose, and lignin, along with lower water-soluble pectin content. Ultrastructural observations further confirmed that LVEF maintained better cell wall integrity by alleviating plasma membrane separation. These findings collectively demonstrate that LVEF treatment effectively delays prune softening through coordinated mechanisms involving suppression of cell wall-degrading enzyme activities, preservation of structural polysaccharides, and maintenance of cellular ultrastructure. The results highlight LVEF's potential as an innovative, non-thermal technology for extending postharvest quality and shelf life of prunes.