Evaluation of postharvest quality of plum (Prunus salicina L. cv. ‘French’) treated with layer-by-layer edible coating during storage

Plum has high nutritional value, good taste and rich flavor. However, the problems of easy decay and short shelf life in plums are prominent during postharvest storage. The effects of chitosan coating, sodium alginate coating and layer-by-layer (LBL) coating on the quality of plums were studied. Our studies demonstrated that different edible coating treatments could maintain fruit quality. Among them, the LBL coating significantly delayed weight loss, color change, reduction of total soluble solids and titratable acidity and kept higher firmness. Moreover, the LBL coated plums displayed higher peroxidase and superoxide dismutase activities, as well as higher contents of ascorbic acid and phenolic compounds compared to control samples. During postharvest storage, anthocyanin synthesis and phenylalanine ammonia lyase activity were significantly inhibited with LBL edible coating treatment. Furthermore, the production of superoxide free radicals and malondialdehyde decreased significantly after LBL edible coating treatment, which alleviated the oxidative damage and maintained the integrity of the membrane. Therefore, the application of LBL edible coating had obvious advantages for delaying senescence and maintaining the postharvest quality of plums in the process of storing.