Production of hydrogen peroxide in commercial orange juice products is related to proximate composition, processing conditions and storage time.

Based on the observed production of H2O2 in formulated beverages containing artificial or 'non-natural' mixtures of anti-oxidants (AOXs), it was hypothesized that the natural redox-active compounds present in orange juice (OJ) might also produce H2O2. Here, we report the levels of H2O2 found in commercially manufactured OJ products in 'fresh' (4 °C on-shelf storage, N = 9) and 'processed' (ambient on-shelf storage, N = 9) categories. The average concentrations of H2O2 immediately after opening the container (T0) were significantly higher (p < 0.01) in processed (11.15 ± 2.83 µM) versus fresh (3.74 ± 2.02 µM) sample sets. Levels of H2O2 at T0 were uncorrelated with storage time post-manufacture and increased after opening (1 to 4-fold), followed by significant decrease after 24 hr (p < 0.05). Using Pearson's correlation analysis; ascorbic acid, total reducible substances and total sugar were each significantly positively correlated, while total protein, fibre and unsaturated fats were each significantly negatively correlated, with H2O2 levels in OJs.

Demonstration of anti-oxidant properties of mustard seed (Brassica juncea) protein isolate in orange juice.

Previous research has shown that formulated and natural beverages containing mixtures of anti-oxidants can produce stable levels of hydrogen peroxide (H2O2). The aim of this study was to demonstrate the ultimate anti-oxidant effects of proteins for suppressing H2O2, using a protein extract from mustard seed (Brassica juncea). The mustard seed protein isolate (MPI) contained âˆ¼51% protein, and 6.4 mg GAe/g TS of total reducible substances, presumably representing secondary metabolites, including polyphenolics. Dose-dependent suppression of H2O2 (present at 110 µM and 550 µM), in fresh and thermally-processed orange juice was complete in the presence of 0.1 mg/mL MPI after 24 hr, with slightly higher anti-oxidant efficacy than the fruit juice-derived reference protein, thaumatin. The combination of thiol-rich amino acid (methionine and cysteine)-containing proteins and other anti-oxidant species in the MPI were highly effective for inhibiting autoxidation-mediated production of H2O2 in orange juice, and may be useful for other manufactured beverages.

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

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 âˆ¼ 42-60 µM (4 °C) or zero after âˆ¼10 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.

Production of hydrogen peroxide in formulated beverages is associated with the presence of ascorbic acid combined with selected redox-active functional ingredients.

Hydrogen peroxide (H2O2) is a reactive oxygen species (ROS) that mediates essential signaling in vivo but may cause irreversible tissue damage under dysregulated or acute exposure conditions. Beverages containing redox-active compounds might produce H2O2 during shelf storage and potentially be consumed. Concentrations of H2O2 in selected 'functional' (including energy, E, n = 28), 'non-functional' flavored, (S, n = 6) and mineral water (W, n = 6) drinks were measured under ambient (i.e., produced in situ) and 'potentiated' conditions (i.e., H2O2 production enhanced by addition of a reducing agent, to simulate availability of reducible substrates in vivo). Under air-saturated conditions, mean H2O2 contents were: 15.60 ± 15.84; 1.39 ± 2.06 and 0.30 ± 0.21 µM in E, S and W drinks, respectively. Under air-saturated, potentiated conditions, mean rates of H2O2 production were 21.7 ± 33.3, 0.98 ± 2.84, and -0.38 ± 1.18 µM/h for E, S and W drinks, respectively. Using multivariate statistics, the ingredient significantly associated with H2O2 production in combination with other ingredients was found to be ascorbic acid.