Activity of Biosynthesized Silver Nanoparticles against Food Spoilage Causing Microorganisms

Aim: To prove the antibacterial sensitivity of phytogenic silver nanoparticles against food spoilage causing organisms such as Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923).

Study Design: Extract based on raw banana peels harnessed from chips manufacturing units was utilized as the reducing agent for the biosynthesis of silver nanoparticles, followed by evaluation of their antibacterial efficacy against common food spoilage organisms through agar diffusion analysis. The experiments were conducted in triplicate, and the average values were depicted graphically.

Place and Duration of Study: Sahrdaya College of Engineering and Technology, Kodakara and Centre for Research on Molecular and Applied Sciences, Thiruvananthapuram, between June to August 2023.

Methodology: Raw banana peel extract was utilized as plant based reducing agent in bioinspired synthesis of silver nanoparticles. The bio-inspired silver nanoparticles formation was confirmed using surface plasmon resonance studies. The biosynthesized particles were isolated through centrifugation and subjected to characterization through Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) analysis to assess their physical structure and chemical composition. The antibacterial efficacy of these particles was assessed through agar diffusion assay, and the minimum concentration of nanoparticles solution to inhibit the microbial growth was determined against food spoilage organisms.

Results: Spherical shaped silver nanoparticles with in the size range of 56-80 nm was synthesized using raw banana peel as reducing agent. These nanoparticles exhibited minimum inhibitory concentrations of 56.07 µg/mL and 79.32 µg/mL, as well as minimum bactericidal concentrations of 156.59 µg/mL and 188.96 µg/mL against Escherichia coli and Staphylococcus aureus respectively.

Conclusion: The silver nanoparticles synthesized with raw banana peel extract as the reducing agent demonstrated antibacterial sensitivity against food spoilage organisms.