Physical and bioactivities of biopolymeric films incorporated with cellulose, sodium alginate and copper oxide nanoparticles for food packaging application

The present work prepared the antibacterial polymeric film (APF) using the different combination of sodium alginate (SA) and cellulose nano whisker (CNW) embedded with copper oxide nanoparticles (CuO NPs). Here, the SA acts as a plasticizer and provides flexibility. The CNW improves barrier properties of the film to limit moisture penetration into food. CuO NPs prevent the microbial contamination to food. Cross-linking and functional relationship of SA-CNW-CuNPs film were confirmed by adopting characterization including SEM, FTIR, EDS and XRD. The film composed with CNW (0.5%)-SA (3%)-CuNPs (5 mM) exhibited promising antibacterial activity against several pathogens in terms of higher zone of inhibition against S. aureus (27.49 ± 0.91 mm), E. coli (12.12 ± 0.58 mm), Salmonella sp. (25.21 ± 1.05 mm), C. albicans (23.35 ± 0.45 mm) and Trichoderma spp. (5.31 ± 1.16 mm). In addition, CNW (0.5%)-SA(3%)-CuO NPs (5 mM) film showed the challenging antioxidant activity in terms of DPPH and ABTS scavenging. Also, the optimized composition of film composed with CNW (0.5%)-SA (3%)-CuO NPs (5 mM) was preventing the microbial contamination in fresh cut pepper (FCP). Therefore, APF composed with CNW (0.5%)-SA (3%)-CuO NPs (5 mM) is proved to be an active food packaging system (FPS) for its utility in food industry to overcome the limitations in conventional food packaging.