Response of Qualitative Traits and Antioxidant Systems to Chitosan Postharvest Treatment in ‘Black Golden’ Japanese Plum

In this study, the influence of a chitosan-based coating was assessed on qualitative traits and non-enzymatic and enzymatic antioxidant systems in Prunus salicina, ‘Black Golden’ Japanese Plum, during 35 days of cold storage followed by 3 days at 24 °C to evaluate its shelf life. Chitosan coating delayed the physico-chemical traits such as the total soluble solids, titratable acidity, firmness and skin color associated with the plum ripening process during cold storage and shelf life. Furthermore, the highest bioactive compounds’ content and antioxidant activity in the coated plum were registered during the stored period. Chitosan-based coating enhanced the activities of superoxide dismutase and ascorbate peroxidase during cold storage and shelf-life. Moreover, this edible coating contributes to reducing membrane damages with lower lipoxygenase activity and, consequently, malondialdehyde accumulation. A multivariate statistical analysis approach identified the two key components, correlated to all analyzed traits, that influenced the changes within chitosan coated and uncoated Japanese plums during storage. Chitosan coating is a cheap and eco-friendly tool to delay ripening process and to improve the antioxidant systems and storability of the ‘Black Golden’ Japanese plum.