Formulations of selected Energy beverages promote pro-oxidant effects of ascorbic acid and long-term stability of hydrogen peroxide

Abstract

Recently, autoxidation mediated by ascorbic acid (AA) and other ingredients, has been implicated in generation of hydrogen peroxide (H₂O₂) in so-called Energy beverages. Here, we report the use of cyclic voltammetry and the FOX assay to monitor at short and long incubation times, respectively, the production and stability of H₂O₂ generated by AA and redox-active ingredients. Levels of H₂O₂ in Energy drinks (36.5 ± 4.0 µM at 4 °C and 64.2 ± 7.6 µM at 20 °C) were found to be stable or increased (p < 0.05) upon vessel opening. A predictive model for the production of H₂O₂ as a function of AA concentration, temperature and incubation time, and depending on ingredients present, indicated that H₂O₂ peaked at 91-726 µM after 1 day and declined to ∼ 42-60 µM (4 °C) or zero after ∼10 days. The research supports that levels of H₂O₂ in beverages containing anti-oxidant mixtures and dissolved oxygen should be monitored and formulations modified to avoid AA autoxidation.

Keywords: Anti-oxidant; Ascorbic acid; Energy beverage; Hydrogen peroxide; Pro-oxidant; Redox.