Starch and green silver nanoparticles based functional nanocomposite films: New insights in fresh fruit packaging

This study uses sour cherries (Prunes census L.) pomace extract as a reducing agent to demonstrate the creation of silver nanoparticles (AgNPs) and preparation of starch film via blending glycerol, polyethylene glycol, and produced starch-AgNPs in different concentrations 1, 2, 3, and 4% of AgNPs with starch film as control. The prepared starch-Ag nanocomposite films were used for packaging strawberries at 4°C. Characteristics of the composite films included FTIR, XRD, SEM, and UV-vis spectroscopy. The composite films with 4% AgNPs showed a smooth surface, as the SEM results showed. Following blending with glycerol and AgNPs, the FTIR result changed the starch’s structure. After adding AgNPs, the composite film’s flexibility improved. The starch-Ag nanocomposite films demonstrated significant antimicrobial activity against Staphylococcus aureus, Escherichia coli, and Candida albicans. Weight loss was used to assess the impact of packing on the quality and shelf life of packed strawberries during storage, the effect time on pH, and microbial growth throughout a 14-day storage period. The results indicate that strawberry fruits may be kept fresher longer and their shelf life preserved with a 3% AgNPs starch-Ag nanocomposite. This is the first research that uses pulp extract from Prunus census L. to describe the production of AgNPs.