Improvement of Postharvest Quality of Plum (Prunus domestica L.) Using Polysaccharide-Based Edible Coatings

Polysaccharide-based edible coatings are served as an attractive preservation method for postharvest maintenance of most fruits. The current study examined the effect of carboxymethylcellulose (CMC)- and pectin (Pec)- based edible coatings on titratable acidity (TA), firmness; vitamin C (vit C); total soluble solids (TSS); pH; total phenolics; anthocyanin and flavonoid contents; total antioxidant capacity (based on 1,1-Diphenyl-2-picryl-hydrazyl hydrate (DPPH)); the activities of peroxidase (POD), polyphenol oxidase (PPO) and polygalacturonase (PG) enzymes; and weight loss during cold storage. The results showed that each coating and their combinations caused positive effects in all measured parameters except weight loss. The applied coatings preserved firmness and improved total phenols, anthocyanin and flavonoid contents, antioxidant capacity and POD activity. In addition, TSS decreased and pH values remained more or less stable with the coating application. The coatings delayed TA and vitamin C loss, and decreased enzymatic activities such as PPO and PG. It could be stated that CMC at 1% and Pec at 1.5% separately demonstrated the best results for most of the measured parameters; and 0.5% Pec + 1.5% CMC could be considered as the best combination. In conclusion, application of CMC, Pec, or their combinations would be considered as an interesting approach to improve postharvest quality characteristics of plum fruit.