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

ABSTRACT

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.