Effects of nano-chitosan and chitosan coating on the postharvest quality, polyphenol oxidase activity and malondialdehyde content of strawberry (Fragaria x ananassa Duch.)

Abstract

Purpose: The aim of this study was to investigate the effects of nano-chitosan and chitosan coating on physico-chemical properties of strawberries during storage. Research methods: Fresh strawberries were coated with different concentrations of chitosan (1%, 1.5%. 2%) or nano-chitosan (0.2%, 0.4%, and 0.8%) and stored in 20C for 21 days. Findings: Coatingstrawberry with0.2% and 0.4% nano-chitosan preserved the overall quality index of the fruit up to 21 days. The treatments reduced weight loss, retained firmness, titratable acidity and L-ascorbic acid, significantly retarded malondialdehyde production and inhibited polyphenol oxidase activity of the stored fruit. The 0.2% nano-chitosan treatment reserved total soluble solid and total anthocyanin content better than the 0.4% nano-chitosan. Although 2% chitosan coating showed the positive effects, the overall quality index of the coated fruit was reduced below the acceptable level after 18 days, shorter as compared to the others coated with the lower concentrations of nano-chitosan. Research Limitations: Nano-chitosan, showing to be the effective coating material in this study, is not popular traded in the industry. Originality/Value: The combination of 0.2 % nano-chitosan coating and storing fresh strawberry at 2°C preserved the quality of fruits up to 21 days. The much lower concentrations of nano-chitosan showed higher positive effects as compared to the higher concentrations of chitosan. This would help to reduce the cost of postharvest handlings for the strawberry industry.