Active chitosan coating to inhibit decay and maintain mango postharvest quality

Area of Science:

• Food Science
• Microbiology
• Materials Science

Background:

• Microbial decay significantly impacts mango postharvest quality, storage, and trade.
• Developing effective antimicrobial strategies is crucial for the mango industry.
• Chitosan, zinc oxide nanoparticles (ZnO-NPs), and Eucalyptus radiata essential oil (EEO) possess antimicrobial properties.

Purpose of the Study:

• To develop and evaluate an active chitosan-based coating incorporating ZnO-NPs and EEO.
• To inhibit microbial decay and preserve the postharvest quality of mangoes.

Main Methods:

• An active coating was formulated using chitosan, ZnO-NPs, and EEO.
• In vitro antimicrobial activity was assessed against Lasiodiplodia theobromae, Staphylococcus aureus, and Escherichia coli.
• In vivo efficacy was evaluated on 'Tommy Atkins' mangoes stored at 9°C for 28 days, assessing firmness, color, respiration, and decay.

Main Results:

• The coating demonstrated high inhibition rates (97.28%) against L. theobromae mycelial growth in vitro.
• Coated mangoes exhibited significantly higher firmness (7.30 N vs. 3.42 N) and reduced decay severity (by ~64.3%) compared to controls.
• Coated fruit showed delayed respiratory peak and lower AUDPC (17.9) against anthracnose.

Conclusions:

• The synergistic combination of chitosan, ZnO-NPs, and EEO provides enhanced antimicrobial efficacy.
• The coating effectively preserves postharvest mango quality, reducing reliance on synthetic fungicides.
• This technology supports extended distribution and improved market access for mangoes.