ENGINEERING OF BIOMASS: BIOPLASTIC FILMS FROM PROTEINS

Organic waste and byproducts of the food and agricultural chains represent promising feedstocks for biopolymers. Proteins, in particular, are a promising category of biopolymers, that exhibit high versatility, adaptability, the capacity to fulfil a broad range of functions and the ability to self-assemble into functional complexes. Moreover, protein-based bioplastics are alternatives to petroleum-based plastics and have the chance to be biodegradable or compostable. In the frame of our research on the engineering of protein based materials, proteins from different sources were compared for the preparation of biofilms. The protein extracts were: bovine serum albumin (BSA), black soldier fly protein extract (BSF), soy protein isolates (SPI), and sericin (SER). The protein content and the molecular mass were determined by means of BCA assay and SDS-PAGE, respectively. The water solubility was assessed as a function of temperature and pH, investigating the proteins denaturation. The film-forming ability was evaluated. Structure-property correlation was studied, by using techniques such as ATR-FTIR, swelling tests, ThT assay, TEM microscopy, TGA-DSC. Biodegradability tests (biological oxygen demand, BOD) were carried out.