FOX-1 reagent in conjunction with catalase was used to discriminate the H2O2 of the other hydroperoxides formed (Bou, Codony, Tres, Decker, & Guardiola, 2008). Fox’s working solution was prepared as follows: 1 ml of a solution containing ammonium ferrous (II) sulphate (25 mM) in sulphuric acid 0.25 M was added to 100 ml of a xylenol orange (125 μM) and sorbitol (100 mM) solution in water.