Effect of Exogenous Sucrose Treatment on the Peel Coloration in Postharvest Peaches

This study was undertaken in order to explore the effect of exogenous sucrose treatment on the peel coloration in postharvest peaches. Freshly harvested ‘Chunmei’ peaches were dipped in 200 mmol/L sucrose and then stored at (20 ± 1) ℃. Fruit quality traits, and the contents of anthocyanins and endogenous sugars and enzyme activities related to anthocyanidin metabolism were measured during postharvest storage. The results showed that sucrose treatment had no significant effects on the respiratory intensity, ethylene release rate, total soluble solids content or hardness of peach fruit (P > 0.05), but it increased the contents of anthocyanins and sucrose. In addition, sucrose treatment maintained relatively high activities of the enzymes related to anthocyanin synthesis in postharvest peach peel, such as chalcone synthase (CHS), flavonoid 3-hydroxylase (F3H), dihydroflavonol reductase (DFR) and UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT). Therefore, exogenous sucrose treatment can improve anthocyanin synthesis by regulating anthocyanidin metabolism-related enzyme activities in peach peel. This finding will provide a reference for research on the improvement of color in peach peel after harvest.