Synergistic effect of starch/polyvinyl alcohol/citric acid films decorated with in-situ green-synthesized nano silver on bioactive packaging films

This study aims to develop bioactive packaging films prepared from starch/polyvinyl alcohol/silver nanoparticles/citric acid (starch/PVA/AgNPs/CA) using a green process. One-pot green synthesis of AgNPs with starch/PVA using sugarcane leaf extract as the reducing substance was used to fabricate the packaging films. The incorporation of CA in the preparation of AgNPs resulted in a smaller particle size and narrower size distribution compared to that without CA. Moreover, the well-dispersed characteristic of AgNPs in the starch/PVA film was observed, resulting in the enhanced mechanical properties of the film. The synergistic effect between AgNPs and 20%CA in starch/PVA was explored against S. aureus and E. coli and showed 2,2-diphenyl-1-picryl-hydrazyl-hydrate-scavenging activity. The Ag ion released in food simulants was lower than the limit set by the European Standard. The results indicated that the starch/PVA/AgNPs containing CA composite films is a promising green food packaging film to retain food freshness.

Automated summary

This study successfully developed bioactive packaging films using a green process, incorporating citric acid to produce smaller nanoparticles and improved antimicrobial properties. The well-dispersed silver nanoparticles in the film exhibited enhanced mechanical properties, while the released silver ions in food simulants were below European Standard limits.