Effect of nano-emulsion coating containing chitosan on storability and qualitative characteristics of strawberries after picking

Strawberries are highly sensitive to fungal agents and، as a result، have a short shelf life. Using chemical fungicides to extend shelf life is a great health concern. Therefore، developing safe methods to control perish ability and maintain quality of strawberries during storage is crucial. Considering the successful application of chitosan in edible coating formulae and its proven antifungal properties due to its nano-particles prompted us to initiate this study aiming at assessing the efficiency of an edible coating based on chitosan nano-emulsion in delaying perish ability، maintaining quality and increasing the shelf life of strawberries. After picking، strawberries were coated with nano-emulsion with particle sizes of 50-100±10 nanometers and containing 0. 5% chitosan as an antimicrobial substance and stored، along with control samples، at a temperature of 4±1℃ and a relative humidity of 70%. At 4-day intervals qualitative indicators، including acidity، soluble solids، texture firmness، weight loss، respiration rate، antioxidant activity، anthocyanin concentration، ascorbic acid and percentage of damage، were determined in three replicates (confidence interval = 95%). Coating strawberries with a nano-emulsion containing 0. 5% chitosan had، in addition to delaying the fruit damage، positive effects on their quality parameters. As compared to uncoated samples، the treated samples were firmner and their weight loss، respiration rate and percent damage were lower. Also،anthocyaninsvandvascorbic acid were better preserved in the coated strawberries than in the control cuncoated sample. Changes in acidity and soluble solids were not considerable. Coating strawberries with a nano-emulsion containing chitosan can be introduced as a safe and effective method to increase their shelf life from 8 days to 20 days (2. 5 times as long) and better preserve their quality.