Physical crosslinking of pea protein-based bioplastics: Effect of heat and UV treatments

Abstract

Climate change and the enhancement of ecology have generated the need to create packaging that is biodegradable and, at the same time, allows food to be preserved efficiently in order to avoid the accumulation of plastic and minimize food waste. In this sense, protein-based bioplastics are a promising alternative, but due to their limited properties they need additional crosslinking in order to compete with conventional plastics. Among them, physical crosslinking is of special interest in the food industry, as it does not generate toxicity problems. In this way, the overall objective of this work was to develop pea protein-based bioplastics by injection moulding, using two different physical crosslinking methods: heat treatment (50ºC-24 h, 120 ºC-4 h and 120 ºC-24 h) and ultraviolet (UV) treatment (50, 120 and 500 mJ/cm2). Thus, different bioplastics were compared based on their mechanical, functional and antimicrobial properties. The relevance of this study is based on the improvement of certain aspects of the mechanical and functional properties of bioplastics by the addition of an extra physical crosslinking stage to the fabrication process. In fact, UV treatment improves the antimicrobial activity of bioplastics, which gives it a significant improvement to compete with conventional plastics in the food sector.