A promising bioactive chitosan film in strawberry fresh-keeping: plasticized with tomato processing by-product extract of deep eutectic solvent

The incorporation of natural extracts of deep eutectic solvent (DES) into polysaccharide represents a promising approach for the development of bioactive edible films. In this study, the effect of whole DES-extracts of tomato processing by-product with lycopene on physical properties and antioxidant properties of chitosan films was firstly studied. Thermal stability (-9.8% for weight loss ratio), UV blocking properties, hydrophilicity (-38.9% for contact angle) of the film were improved. Free radical scavenging rate was increased by about 1.6 times, and the formation rate of oxidation product for olive oil was reduced especially in the first 10 days with the addition of DES-tomato extracts. The decay rate of strawberry treated with DES-tomato extracts decreased by -55.41%, and the loss of VC, polyphenol and catalase activity and malondialdehyde of oxidation product clearly decreased. Chitosan coating with whole DES-tomato extracts improved the storage quality and extended the shelf life of strawberries, was a promising method for the fresh-keeping of fruits and vegetables.