Inhibitory effect of low-voltage electrostatic field on postharvest black spot development in cauliflower

• LVEF inhibited decay-related microbes and reduced black spot formation in cauliflower. • LVEF enhanced nutrients by increasing amino acids, acids, sugars, and reducing alkaloids. • LVEF stabilized glucosinolates by suppressing DEGs in aromatic amino acid pathways. • LVEF reduced ROS bursts and boosted antioxidant capacity during storage. • LVEF stabilized energy metabolism via sugar metabolism, TCA cycle, and phosphorylation. Postharvest cauliflower rapidly deteriorates, typically exhibiting yellowing, tissue softening, off-flavor development, and black spot decay. effectively delayed quality loss and inhibited decay-associated microorganisms. LVEF reduced black spot formation and sensory degradation by limiting carbohydrate and amino acid catabolism and by modulating energy metabolism. Moreover, LVEF regulated the biosynthesis of aromatic and sulfur-containing amino acids and glucosinolates, thereby suppressing unpleasant odors and preserving cauliflower flavor up to 8 days postharvest. The treatment enhanced curd antioxidant capacity by preventing reactive oxygen species (ROS) bursts and promoting scavenging activity. Molecularly, LVEF altered the expression of genes involved in starch and sucrose metabolism ( sucrose synthase, β-glucosidase, β-fructofuranosidase ), the TCA cycle ( malate dehydrogenase, citrate synthase, ATP citrate lyase, aconitate hydratase ), and oxidative phosphorylation ( V-type ATPase subunit D-like, ATPase 2, plasma membrane-type-like ), thereby stabilizing postharvest energy metabolism. Microbial suppression correlated mainly with changes in vitamin C, polyphenols, flavonoids, and lipid contents. This study presents the first integrated transcriptomic, metabolomic, and metagenomic analysis, revealing that a LVEF extends the postharvest preservation of cauliflower by synergistically activating host defense-related metabolic pathways and suppressing the proliferation of surface spoilage microorganisms, thereby reducing black spot incidence and delaying senescence.