Effects of slightly acidic electrolyzed water on the postharvest quality of Ottelia acuminata

Freshly harvested vegetables, such as Ottelia acuminata , are prone to water loss, wilting, yellowing, and microbial damage owing to accelerated biochemical reactions. Slightly acidic electrolyzed water (SAEW) enhances the activity of disease-resistant enzymes, improves disease resistance in vegetables during storage, and maintains postharvest freshness and nutritional quality. Although SAEW has been widely used in order to enhance the postharvest quality of various vegetables, research on its regulatory mechanisms in aquatic vegetables remains limited. In this study, physiological and biochemical indicators and metabolomic data were integrated to elucidate the differences in the preservation mechanisms of SAEW, low-temperature storage, and PE bag treatments in O. acuminata . Physiological and biochemical results showed that the key indicators of appearance and nutritional quality, including flavonoids, total phenols, chlorophyll, chlorophyll b, and starch content, reached their highest levels under the combined treatment of SAEW and low-temperature storage. Metabolomic analysis revealed that numerous differentially accumulated metabolites (DAMs) participate in key pathways, including phenylpropanoid and flavonoid biosynthesis. These findings indicate that SAEW treatment allocates more resources to the accumulation of antioxidant and antimicrobial compounds in secondary rather than primary metabolic pathways. DAMs were enriched in pathways related to antioxidant activity, membrane stabilization, and stress responses, suggesting their potential contribution to postharvest preservation under SAEW treatment. This study has elucidated how SAEW combined with low-temperature storage preserves the postharvest quality of O. acuminata , and proposes SAEW as an effective postharvest strategy to reduce spoilage and deterioration and meet consumer demand for high-quality vegetables. • SAEW with low temperature best maintains O. acuminata postharvest quality. • Combined treatment increased flavonoids, phenols, chlorophyll. • SAEW regulated key metabolites in flavonoid, phenylpropanoid, and linolenic pathways. • DAMs associated with maintaining nutrient quality increased.