Citrus-derived silver nanoparticles for food safety: Biodegradable packaging with antimicrobial and oxidative...

Citrus peel extracts, which are rich in bioactive compounds, offer an eco-friendly method for the synthesis of AgNPs, supporting sustainable food packaging. This study explored alginate-gelatin biocomposite films incorporating AgNPs synthesised from lemon and tangerine peel extracts. AgNPs were optimised using response surface methodology (RSM) and characterised using FTIR, XRD, and TEM. Their antioxidant (DPPH) and antimicrobial activities were evaluated against Staphylococcus aureus, Salmonella typhimurium, and Listeria monocytogenes. Films with L-AgNPs reduced lipid oxidation to TBARS values as low as 4.85 μmol MDA/kg and achieved inhibition zones of 13.50-16.50 mm. Structural analyses (SEM, FTIR, and XRD) confirmed successful nanoparticle incorporation. Evaluations of moisture content, water solubility, and swelling behaviour demonstrated enhanced film performance. Microbiological tests revealed significant bacterial inhibition (p < 0.05) in the L-AgNP films. These findings support the potential use of citrus-derived AgNPs as sustainable natural agents in active food packaging to enhance food preservation and safety.