Green synthesis of nanosilver coating on paper for ripening delay of fruits under visible light

Active packaging containing photocatalyst is generally used to solve the issues of loss and quality deterioration of fresh fruits. However, only ultraviolet (UV) light can activate these photo-catalysts in ethylene photo degradation. To overcome this limitation, green synthesized silver nanoparticles (AgNPs) that inhibits ethylene gas production under visible light has been developed. In this study, spent green tea was mixed with deionized water at various ratios ranging from liquid to solid to obtain spent green tea extract (ex-SGT) having different concentrations used for synthesis of AgNPs. The results indicated that a good distribution of particles with a bandgap energy of 2.17 eV which was in the visible region for ethylene photo-degradation was successfully obtained with the synthesized AgNPs-60 (ex-SGT at the ratio of 60:1). The coated paper possessed an antibacterial activity and decreased the ethylene concentration in mango's packaging. Based on the finding in this work, it appears that the coated paper could have potential to be used for novel packaging of fruits to delay their ripening so that their freshness can be maintained.

Automated summary

This study developed silver nanoparticles synthesized using spent green tea to coat paper for antibacterial and ethylene-reducing properties, potentially delaying the ripening of fruits in novel packaging.