Impact of Low‐Voltage Electrostatic Field Combined With Melatonin on Postharvest Quality of Sweet Cherry Under Cold Atmospheric Plasma Pretreatment

ABSTRACT

This study investigates the regulatory effects of low‐voltage electrostatic field (LVEF) in synergy with melatonin (MT) on the postharvest quality of sweet cherries pretreated with cold atmospheric plasma (CAP). “Rainier” sweet cherries ( Prunus avium L.) served as the experimental subjects. After uniform CAP pretreatment, the fruits were subjected to MT immersion (100 μmol L ⁻¹ ), LVEF treatment (200 V), or a synergistic combination of both, and subsequently stored at 4°C for 20 days. Throughout the storage period, we periodically monitored color, texture, browning, weight loss, decay, and associated physiological indices. The results demonstrate that the synergistic treatment of LVEF and MT yields superior preservation efficacy. By Day 20, this group maintained L * and a * values of 48.59 and 13.22, respectively, with a total color difference (Δ E *) of merely 5.14, exhibiting significantly higher color stability than other treatments ( p  < 0.05). Furthermore, the LVEF+MT group showed a firmness decline of only 19.07% (988.40 g) and a skin penetration force loss of 5.36%, both significantly lower than the control (CK) group's 43.63% and 29.10%, respectively. Stem browning rates and fruit browning indices were recorded at 19.67% and 3.65%, representing reductions of 80.32% and 78.32% compared to the CK group. Additionally, weight loss (4.42%) and decay rates (6.43%) decreased by 59.73% and 65.76% relative to the CK group. Total soluble solids (TSS) were maintained at a high level (17.97% on Day 20), and pH fluctuations were minimized (final value 3.77). Principal component analysis (PCA) further confirms that the LVEF+MT group achieved the highest composite scores across all storage intervals. In summary, the synergistic application of LVEF and MT, following CAP pretreatment, effectively retards postharvest quality deterioration in sweet cherries, offering a novel strategy for the preservation of perishable fruits.