Impact of cross-linker types and concentrations on physical, mechanical, and barrier properties of collagen hydrolysate obtained from leather industry trimming wastes and sodium alginate-based films

The depletion of global petrochemical resources, coupled with the environmental challenges arising from the extensive use of traditional plastics, has led to greater interest in the research of environmentally friendly biodegradable materials that can be used in various applications. The weak water barrier properties of collagen hydrolysate (CH) obtained from leather industry trimming waste seriously limit its practical application areas. In this study, CH/sodium alginate (CH/SA)-based films were produced using the solution casting method because they are non-toxic and biocompatible. The CH/SA composition with the best water barrier property was selected and cross-linked with transglutaminase (TG), genipin (GP), and tannic acid (TA). Cross-linking significantly increases the mechanical strength, thermal ability, and hydrophobicity of the films, thereby reducing their WVP and WS. The film sample CH40/SA60/GP^0.4%, out of all the examined specimens, demonstrated superior overall performance, characterized by a TS of 21.209 MPa and a WS of 19.896%. The results indicate that biodegradable films serve as a promising foundation for the development of packaging materials. Consequently, this study offers an effective approach to creating high-performance, environmentally friendly, and degradable CH/SA-based films and products.