Novel Bioplastic from Single Cell Protein as a Potential Packaging Material

Microbial treatment of biodegradable wastes not only ensures neutralization of harmful substances such as volatile organic compounds but also enables valorization and bio-circularity within the society. Single cell protein (SCP) is a value-added product that can be obtained from biodegradable waste materials such as food waste via microbial fermentation. In this article, SCP derived from potato starch waste was demonstrated as a viable alternative to existing plant/animal proteins used in the production of films, for example, packaging applications. Flexible glycerol-plasticized SCP films were prepared through compression molding, and tensile tests revealed strength and stiffness similar to other plasticized protein films. The oxygen barrier properties were significantly better compared to the common polyethylene packaging material, but as with other highly polar materials, the SCP material must be shielded from moisture if used in, for example, food packaging. The biodegradation test revealed a similar degradation pattern as observed for a household compostable bag. The results showed that SCP-based bioplastic films can be considered as potential alternative to the existing plant/animal protein films and certain synthetic polymers. An important advantage with these protein materials is that they do not cause problems similar to microplastics.