Argovit™ silver nanoparticles transform agro-waste into phenolic biofactories: Postharvest stress for high-value compound production in prickly pear peels

Abstract

The growing demand for food has resulted in an increased generation of plant waste residues. These waste materials contain various bioactive compounds, but their concentrations are typically low, rendering their extraction economically unviable. In this study, we assessed the impact of abiotic stress induced by silver nanoparticles (AgNPs) on the compounds derived from red and green prickly pear peels. Six different AgNP lots were tested at varying concentrations. The total phenol content was consistently higher than that of the control group across all lots. Notably, the AgNP systems exhibited selectivity in inducing the formation of specific compounds, such as caffeic (10.36%), vanillic (6.71%), p-coumaric (6.63%), malic (4.86%) acids, and catechin (46.15%). Moreover, the betanin content in red prickly pear increased by up to 2.4 times compared to the control group. However, the data analysis indicated a tendency towards increased variability in phenolic acids and flavonoids. This suggests that the AgNP systems might be activating these metabolic pathways. These findings are highly relevant as they demonstrate the potential of AgNP systems to enhance the accumulation of bioactive compounds in agro-industrial waste materials, which can then be utilized in the development of functional ingredients.