Ultrasound-treatment as a promising strategy to develop biodegradable films obtained from mushroom waste biomass

Abstract

This work reports on the valorisation of discarded mushroom biomass generated in the industry and the waste produced after a β-glucan extraction process from three different species ( Grifola frondosa, Lentinula edodes, and Pleurotus ostreatus ) for the production of biobased and biodegradable films. Initially, the composition of the starting material was characterized before film production. The results evidenced no significant compositional differences between the discarded mushrooms, proteins, and β-glucans being the main components in all varieties. In contrast, the residues were mainly composed of carbohydrates (glucans and chitin). The films obtained from the residues presented a very rigid behaviour, with higher elastic moduli (ca. 2–4.5 GPa) and lower elongation values (ca. 1%) compared to their counterparts prepared with the mushroom's discards. The developed films outperformed benchmark biopolymers in terms of barrier properties with the additional advantages that they can be directly produced from fungal biomass (without plasticizers or any other additives) and they proved to be easily disintegrated according to the standard ISO 20200. • Films were prepared from fungal biomass (without plasticizers or any other additives). • No significant compositional differences between the discarded mushrooms. • The residues were mainly composed of carbohydrates (glucans and chitin). • Films obtained from the residues showed a very rigid behavior and good barrier properties. • All of them were disintegrated according to the standard ISO 20200.