Developing environmentally sustainable biodegradable multifunctional bio-composite films is an effective strategy for ensuring food chain security. This study initially prepared inclusion complexes (HP-(3-CD@EGCG) of Hydroxypropyl-(3-cyclodextrin (HP-(3-CD) and EGCG to ameliorate the stability of EGCG. Then HP-(3-CD@EGCG and different ratios of lignin were incorporated into gelatin solution through cross-linking polymerization to prepare an antioxidant, antibacterial and biodegradable composite film (HP-(3-CD@EGCG/Lignin/Gelatin). The results illustrated that HP-(3-CD crosslinked with EGCG and the encapsulation rate of EGCG reached 82.26%, and lignin increased the comprehensive characteristics of the gelatin-based composite films. The hydrophobicity of the composite films increased with increasing lignin concentration, reaching a water contact angle of 117.33 degrees; Furthermore, the mechanical characteristics and UV-light/water/oxygen barrier capacity also increased significantly. The composite films showed excellent antioxidant and antimicrobial properties, which also verified in the preservation of tomatoes and oranges, extending the shelf life of the fruit. It is worth mentioning that lignin has no effect on the biodegradability of the composite film, and the degradation rate in the soil reached 80% on the 10th day. In summary, biodegradable multifunctional environmentally friendly composite films based on gelatin and loaded with lignin and HP-(3-CD@EGCG inclusion complexes are anticipated to be applied in fruit and vegetable preservation.

Conventional food packaging films pose significant environmental hazards. Consequently, there has been a burgeoning interest in biopolymers, leading to numerous studies to develop biodegradable and bioactive films suitable for the food packaging industry. In this study, we present a novel environmentally-friendly chitosan-based film incorporating berberine, a bioactive compound abundant in various plants. Before blending with a chitosan solution, berberine chloride's water solubility was enhanced using 2-hydroxypropyl-beta-cyclodextrin. Fourier transform infrared spectroscopy confirmed the interactions between berberine and chitosan. Scanning electron microscopy and atomic force microscopy analyses demonstrated the even distribution and good compatibility of berberine within the chitosan film. By blending berberine with chitosan, the obtained biopolymer film exhibited improved mechanical properties compared to the control film. Differential scanning calorimetry analysis showed that berberine incorporation reduced the glass transition temperature from 89 degrees C to 68 degrees C. The film also blocked the UV light almost 100%. The addition of berberine decreased the water vapour permeability of the chitosan film while increasing the swelling ratio and water solubility. The berberine-incorporated chitosan film exhibited an antioxidant capacity of 33.7% as measured by the 2,2 diphenyl-1-picrylhydrazyl assay, which was significantly higher than that of the chitosan film, which has 5.92%. The film also demonstrated antimicrobial activity with a reduction in B. cereus and S. typhimurium growth compared to the control. Additionally, the degradation study revealed that the film degraded by 82.5% within ten days under soil. Our findings suggest that the chitosan-berberine film holds promise for applications in the food packaging industry.