Fabrication of composite films based on chitosan and vegetable-tanned collagen fibers crosslinked with genipin

Authors: LIU, JIE - Zhengzhou University; LIU, YANCHUN - Zhengzhou University; Brown, Eleanor - Ellie; MA, ZHENGXIN - Zhengzhou University; Liu, Cheng Kung

Submitted to: Journal of American Leather Chemists Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/6/2021
Publication Date: 10/1/2021
Citation: Liu, J., Liu, Y., Brown, E.M., Ma, Z., Liu, C. 2021. Fabrication of composite films based on chitosan and vegetable-tanned collagen fibers crosslinked with genipin. Journal of American Leather Chemists Association. 116(10):345-358.

Interpretive Summary: The utilization of biocomposite films for packaging applications has attracted intense scientific and practical interests because of their outstanding physical properties and versatile processibility arising from their unique structure. Moreover, the rapidly growing demand for antimicrobial packaging materials leads to a strong interest in biocomposite films to suppress the growth and accumulation of harmful bacteria. In this study, biocomposite films made from genipin-crosslinked chitosan and vegetable-tanned collagen fibers (VCF) were prepared using a solution casting method. Results indicated that VCF was compatible with the chitosan substrate and formed additional hydrogen bonds. Further analysis revealed that VCF was embedded in a continuous chitosan network. The resultant composite films showed enhanced optical barrier performance, water resistance, thermal stability and tensile strength. Films containing VCF also exhibited higher water vapor permeability and elongation at break than those of the control film. In addition, the composite film showed inhibitory effects against Gram-positive and Gram-negative bacteria. Therefore VCF can be used as a potential filling material to improve the practical value of chitosan films and provide a new approach for value-added utilization of solid leather waste.

Technical Abstract: The leather industry generates considerable amounts of solid waste and raises many environmental concerns during their disposal. The presence of collagen in these wastes provides a potential protein source for the fabrication of bio-based value-added products. Herein, a novel composite film was fabricated by incorporating vegetable-tanned collagen fiber (VCF), a mechanically ground powder-like leather waste, into a chitosan matrix and crosslinked with genipin. The obtained composite film showed a compact structure and the hydrogen bonding interactions were confirmed by FTIR analysis, indicating a good compatibility between chitosan and VCF. The optical properties, water absorption capacity, thermal stability, water vapor barrier property and mechanical properties of the composite films were characterized. The incorporation of VCF into chitosan led to significant decreases in opacity and solubility of the films. At the same time, the mechanical properties, water vapor permeability and thermal stability of the films were improved. The composite film exhibited antibacterial activity against food-borne pathogens. Results from this research indicated the potential of the genipin-crosslinked chitosan/VCF composites for applications in antimicrobial packaging.