Preparation and Properties of Oligo-chitosan Cross-linked Gelatin Biodegradable Films

Objective: The aim was to evaluate the effect of oligo-chitosan modification on the properties of gelatin-based films. Methods: The gelatin-based films were prepared by using gelatin extracted from scrap pig skin as a cheap raw material and chitosan and polyvinyl alcohol as cross-linking agents. The structural and mechanical properties were characterized by Fourier infrared spectroscopy, X-ray power diffractometry, scanning electron microscopy, spectroscopy, and tensile test. Meanwhile, the ability of gelatin-based films in antioxidant, antibacterial, water stability and biodegradation were evaluated. Results: The multi-cross-linked gelatin-based films showed excellent mechanical properties, with a highest fracture stress of 37.09 MPa, a maximum tearing energy of 56.71 kJ/m², and a good physical form maintained after 48 h of immersion in water. In addition, the films possessed excellent light transmission (up to 92.32%), good oxidation resistance (radical scavenging capacity up to 75.12%), excellent antimicrobial and biodegradability (complete degradation time <45 h). Conclusions: The addition of oligo-chitosan has changed the properties of gelatin-based films in mechanics and biodegradation, and endowed the films with good antibacterial and antioxidant capacity, indicating that it had great potential application value in food packaging.