Synergistic Effects of Chitosan and Organic Acids on the Antimicrobial, Antifungal and Antioxidant Properties of Edible Coatings

This study examines the effectiveness of a chitosan-based edible coating, enhanced with citric, ascorbic, and acetic acids, in improving the microbiological quality and extending the shelf life of tomatoes ( Solanum lycopersicum ). Various formulations were tested for their antimicrobial and antifungal properties, targeting bacteria such as Escherichia coli and Staphylococcus aureus , and fungi like Alternaria arborescens and Alternaria tenuissima . The selected formulation—comprising 1% chitosan, 0.5% glycerol, and 1% each of citric and ascorbic acids—demonstrated significant antibacterial, antifungal, and antioxidant effects. Antibacterial tests revealed stronger inhibition against S. aureus than E. coli , while antifungal activity showed 100% growth inhibition in both Alternaria strains. Additionally, tomatoes treated with this coating displayed prolonged antioxidant activity and reduced microbial counts, emphasizing its potential in improving food safety and reducing spoilage.