This study rapidly isolated lignin from wheat straw by constructing several ternary eutectic solvent systems, followed by preparing lignin nanoparticles (LNPs) via an ultrasonic-assisted antisolvent method. Subsequently, LNPs of varying concentrations and types were incorporated into a chitosan (CS) matrix. A series of LNP/CS composite films was prepared by the cast-film method and applied to the preservation of cherry tomatoes. Results revealed that LNP incorporation significantly enhanced the composite film's overall performance. Compared to pure CS films, LNP/CS composites demonstrated superior water resistance, UV barrier properties, mechanical strength, thermal stability, antioxidant capacity, and antibacterial activity. Among these, the composite film incorporating 20 % LNPs prepared from choline chloride/1,4-butanediol/aluminum chloride (CBA-LNPs) exhibited the most optimal overall performance. Subsequently, this composite film was applied to studies on cherry tomato preservation. Results demonstrated that coating with the CBA-LNPs/CS composite film effectively mitigated quality deterioration during storage, with the optimal preservation efficacy observed at an LNPs content of 20 %. Following 14 days of refrigerated storage at 4°C, the 20 % CBA-LNPs/CS-coated group maintained the most intact appearance and color compared to the untreated group. Its spoilage rate and weight loss rate were reduced by 63.15 % and 28.72 %, respectively, whereas firmness was increased by 117.76 %. Additionally, this treatment effectively retarded the loss of titratable acidity and vitamin C content. In summary, LNP/CS composite films demonstrate broad potential as novel bio-based materials for food preservation. • Green lignin nanoparticles (LNPs) were synthesized for chitosan film enhancement. • LNPs improved film strength, UV blocking, antioxidant, and antibacterial properties. • LNP/CS films demonstrate outstanding preservation efficacy for cherry tomatoes. • The results provide a sustainable pathway for bio-based food packaging.
Su et al. (Tue,) studied this question.