Chitosan-Based Edible Coating Delays Fungal Decay and Maintains Quality of Strawberries during Storage

摘要

Strawberry is a scrumptious but highly perishable fruit. Rapid softening and fungal decay are major challenges in extending storage quality and reducing postharvest losses of this delicate fruit. Chitosan is an environment-friendly hydrocolloidal polysaccharide with well-known antifungal properties. In this study, efficacy of edible coatings of chitosan to maintain fruit quality and storability of strawberries (Fragaria × ananassa Duch., cv. Chandler) was assessed. Healthy, uniformly sized and red ripe strawberry fruits were coated with 0, 0.5, 1 or 1.5% chitosan and stored at 5°C. Changes in physical, biochemical and organoleptic properties of the fruits were assessed every alternate day. Compared to control fruits, chitosan-coated strawberries remained 92% marketable for 8 more days due to significant decrease in fruit decay and sustained structural integrity, fresh weight, total soluble solids, total sugars and organoleptic attributes. Strawberries coated with 0.5% chitosan exhibited relatively less fruit decay and better fresh weight, total soluble solids and sensorial features compared to fruits coated with higher concentrations of chitosan. Interestingly, decline in total titratable acids and ascorbic acid contents in chitosan-coated fruits was steeper than decline in control fruits which suggested that chitosan coating accelerated degradation of organic acids in strawberries. Overall, findings of this study suggest that pre-storage coating of strawberries with 0.5% chitosan may help maintain fruit physical attributes whereas 1.0% chitosan coating helps strawberries retain biochemical attributes followed by 1.5% chitosan coating.