Incorporation of ascorbic acid in chitosan-based edible coating improves postharvest quality and storability of strawberry fruits

Recent postharvest studies have shown that adding an antioxidative agent in a polysaccharide-based edible coating reduces postharvest losses and extends the shelf life of a coated fruit. Therefore, the effect of addition of ascorbic acid (AA, 1%) in chitosan-based coating (CH, 1%) on strawberry fruits under cold storage conditions at 4 ± 1 °C and 85 ± 5% RH was investigated for 15 days. It was observed that addition of AA in CH coating reduced weight loss, decay percentage, malondialdehyde content and hydrogen peroxide compared to CH alone. The combined CH + AA application also suppressed fruit softening by reducing cell wall degrading enzymes (i.e. polygalacturonase, cellulase and pectin methyl esterase) activities. In addition, AA incorporation catalyzed ROS scavenging enzymes (i.e. ascorbate peroxidase, catalase, peroxidase and superoxide dismutase) activities. CH + AA treatment also maintained fruit quality by conserving higher total soluble solids, titratable acidity, ascorbic acid content, total phenolics and antioxidant activity. Sensory quality (color, taste, glossiness and overall acceptability) of fruits coated with CH + AA treatment was also stable during storage. Conclusively, the combined CH + AA application is an effective approach to maintain the postharvest quality of strawberry fruits under cold storage.