Repression of cell wall metabolism by calcium lactate enhances the postharvest quality maintenance of Jinfeng pear fruit

Quality deterioration of pear fruit is a significant factor contributing to postharvest losses. Calcium lactate, as a food additive, was investigated in this study to estimate its impacts on quality indexes and cell wall metabolism of Jinfeng pear fruit during storage at room temperature. Results demonstrated that calcium lactate effectively maintained higher levels of titratable acidity, flesh firmness, and soluble solids content in pears. Additionally, it delayed the decline of chlorophyll content and inhibited the changes in L*, a*, b* values, and ΔE of pear fruit. The activities and gene transcriptions of pectin methyltranseliminase, pectate lyase, polygalacturonase, pectinmethylesterase, β-glucosidase, cellulase, and β-galactosidase of pears were also inhibited by calcium lactate. Moreover, calcium lactate delayed the decrease of water-insoluble pectin and cellulose contents, and inhibited the increase of water-soluble pectin content and polygalacturonic acid transeliminase activity. These results imply that postharvest application of calcium lactate can effectively retard the softening process of Jinfeng pears and maintain their postharvest quality by regulating cell wall metabolism.