Chitosan-gallic acid conjugate edible coating film for perishable fruits

Approximately 30 % of global agricultural land is used to produce food that is ultimately lost or wasted, making it imperative to explore strategies for mitigating this waste. This study explored the potential of chitosan (CS) derivatives as edible coatings to extend food shelf life. Although soluble CS derivatives such as glycol CS are suitable coatings, their antimicrobial properties often diminish with increased solubility. To address this issue, gallic acid (GA), a polyphenol, was conjugated with CS using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide (EDC/NHS) chemistry to create edible coating solutions. The resulting CS-GA films exhibited remarkable solubility, mechanical strength, UV-blocking properties, and superior antioxidant and antimicrobial properties. Furthermore, these films exhibited a high affinity for hydrophobic fruit surfaces while also facilitating easy washing, making them an alternative for consumers who are averse to film-coated products. The CS-GA-coated fruits exhibited minimal surface spoilage, decreased mass loss, and increased firmness. Therefore, these CS-GA conjugate coatings hold significant potential as eco-friendly, edible, and washable food packaging coatings. [Display omitted] •Food loss due to the spoilage of fresh produce is critical issue.•Edible and water-soluble chitosan derivative was synthesized using chitosan and gallic acid.•Coated chitosan derivative exhibits excellent UV-protection, antioxidant and antibacterial activities.•This edible coating exhibits significant potential to effectively address the food loss issue.