Sodium alginate coating improves refrigerated sweet corn quality: Hormonal and metabolic responses

Abstract

Sweet corn, widely consumed as a vegetable or fruit for its sweetness and nutrition, depends on the cold chain for preservation. Although refrigerated storage effectively extends shelf life, the long-term exposure to low temperature may degrade its quality and taste, and the current storage duration also requires improvement, highlighting the urgent need to innovate preservation techniques for existing methods. This study examines the effectiveness of sodium alginate coating (SAC) at varying concentrations (0.5 %, 1 %, and 1.5 %) in prolonging the shelf life of sweet corn during low temperature storage. Research findings indicate that 1 % SAC, the optimal concentration for alleviating kernel shrinkage and browning while preserving fine texture and sweetness, can extend the 4 °C storage shelf life of sweet corn by 6 days. RNA sequencing and physiological assays indicate that SAC maintains the storage quality of sweet corn by regulating phenylpropanoid biosynthesis, starch and sucrose metabolism, glycolysis, pyruvate metabolism, and antioxidant capacity. This regulatory effect may be mediated by enhanced gibberellin synthesis and the suppression of O-glucosylation of dihydrozeatin and cis-zeatin. This study concludes that 1 % SAC enhances the quality of sweet corn during low temperature storage by modulating metabolic responses via key hormonal pathways, providing a promising strategy for postharvest management.