Pea Protein-Based Bioplastics Crosslinked with Genipin: Analysis of the Crosslinking Evolution

Abstract Replacing conventional plastics with other products obtained from biobased and biodegradable raw materials is an increasingly studied solution. In this line, the development of protein-based bioplastics is a promising alternative. However, for some applications, such as packaging it would be necessary to improve their properties by including an additional stage to crosslink the protein chains during the production of bioplastics. Therefore, pea protein-based bioplastics crosslinked with genipin, a natural non-toxic chemical crosslinking agent, are evaluated in this study. The bioplastics are obtained via injection moulding and genipin, is included in the initial formulation. Specifically, the concentration of genipin and the effects on the protein blends with genipin over days are evaluated. The evolution of the reaction is followed by the colour change of the blend, together with thermal analyses and infrared spectroscopy. Results showed the evolution of the crosslinking in the blends resulted in conformational changes that resulted in the modification of the initial yellowish colour to a blueish system. Respect their bioplastics, more deformable systems with a lower water absorption capability are obtained by using genipin as crosslinking agent.