Hydrophobic modified starch reinforced chitosan/lignosulfonate composite film for cherry tomatoes preservation

To address the environmental pollution caused by petroleum-based plastic packaging, the development of high-performance biodegradable films has become a key research focus in the field of food packaging. In this study, hydrophobically modified starch (AKDSC) was prepared via the esterification reaction of alkyl ketene dimer and subsequently introduced into a chitosan/sodium lignosulfonate (CH/SL) composite system, successfully constructing a multifunctional composite film (CH/SL-AKDSC). The structural characterization results indicated the formation of a denser hydrogen bond network between the phenolic hydroxyl/amino groups in CH/SL and the hydroxyl groups in AKDSC. The performance tests showed that the film exhibited a water contact angle of 105.9°, an oxygen transmission rate as low as 1.18 g/(m²·d), and an ultraviolet shielding rate of over 99%. In a 10-day cherry tomato preservation experiment, the CH/SL-AKDSC film demonstrated good preservation effects, highlighting its practical application potential in green and efficient food packaging.