Asparagine-Capped Silver Nanoparticles for the Photocatalytic Degradation of Metanil Yellow Dye: An Adulterant in Turmeric Powder

This study specifically aimed to identify the presence of non-permitted food colorings in spices and evaluate a novel method for reducing them using silver nanoparticles. Spices, known for their aromatic and pungent qualities, play a crucial role in enhancing the flavor of food and beverages. However, the adulteration of spices presents a serious threat to human health, making it imperative to detect harmful substances. Asparagine-capped silver nanoparticles (Asp-AgNPs) demonstrated remarkable efficacy and could photo-catalytically reduce metanil yellow dye. To assess real-world implications, four samples of turmeric powder were collected from local markets in Agra. The focus was on testing for adulteration with metal yellow, one of the most widely used but prohibited food colorants. The investigation involved carefully observing color changes in the test samples. The results revealed that two out of the four turmeric powder samples contained metanil yellow dye, highlighting a concerning prevalence of adulteration in commonly consumed spices. Asparagine-capped silver nanoparticles (Asp-AgNPs) demonstrated remarkable efficacy, capable of photo-catalytically reducing approximately 95.4% of the adulterant dye within 60 minutes when in contact with the prepared catalyst under optimized conditions. Our findings revealed that the asparagine-capped silver nanoparticles (Asp-AgNPs) performed exceptionally well as catalysts, facilitating a remarkable reduction of metal yellow dye, thus achieving an impressive 95.4% reduction rate. This research suggests that asparagine-capped silver nanoparticles could be significant catalysts for effectively degrading toxic dyes in various applications.