The use of nanomaterials in consumer products is rapidly expanding. In most studies, nanomaterials are examined
as isolated ingredients. However, consumer products such as foods, cosmetics, and dietary supplements are complex chemical
matrixes. Therefore, interactions between nanomaterials and other components of the product must be investigated to ensure the
product’s performance and safety. Silver nanomaterials are increasingly being used in food packaging as antimicrobial agents.
Thiol-containing compounds, such as reduced glutathione (GSH), cysteine, and dihydrolipoic acid, are used as antioxidants in
many consumer products. In the current study, we have investigated the interaction between silver nanomaterials and thiolcontaining antioxidants. The selected Ag nanomaterials were Ag coated with citrate, Ag coated with poly(vinylpyrrolidone), and
Au nanorods coated with Ag in a core/shell structure. We observed direct quenching of the 1,1-diphenyl-2-picrylhydrazyl radical
(DPPH) by all three Ag nanomaterials to varying degrees. The Ag nanomaterials also reduced the quenching of DPPH by GSH
to varying degrees. In addition, we determined that the mixture of GSH and Au@Ag nanorods held at 37 °C was less effective at
quenching azo radical than at ambient temperature. Furthermore, we determined that Au@Ag nanorods significantly reduced the
ability of GSH and cysteine to quench hydroxyl and superoxide radicals. The work presented here demonstrates the importance
of examining the chemical interactions between nanomaterials used in products and physiologically important antioxidants.