Biodegradable active films based on Chlorella biomass and cellulose nanocrystals isolated from hemp stalk fibers

Cellulose nanocrystals (CNC)-reinforced biopolymers have emerged as a widely embraced approach for enhancing the characteristics of biopolymers due to their exceptional properties. Biocomposite (Chl-CNC) films were fabricated by blending Chlorella biomass and varying concentrations of CNCs via a solution casting technique. CNCs were effectively isolated from hemp stalk fibers, as confirmed by structural, surface, thermal, and morphological analysis. The crystallinity of films increased by CNC incorporation, which was confirmed by the XRD. The presence of molecular interactions between CNC and protein-rich Chlorella biomass was illustrated with the FTIR analysis. These interactions enhanced the physicochemical properties of the films. Further, films demonstrated a high level of soil biodegradation in the 42 days, while their total phenolic, chlorophyll, carotenoid contents, and antibacterial activity were unaffected by the incorporation of CNCs. The Chl-CNC films, regardless of CNC addition, indicated antimicrobial activity toward Escherichia coli but not Staphylococcus aureus. These results indicate that developed biobased and biodegradable Chl-CNC films could be highly beneficial in active food packaging applications.