Broccoli ethanolic extracts were prepared as described in Section 2.7 and the supernatants were used to measure antioxi-
dant capacity with DPPH and ABTS+ radicals. The DPPH assay was done according to the method described by Brand-Williams et al. (1995) with minor modifications. Test tubes containing 0, 50, 75, 100 and 150 mL of sample and ethanol to a final volume of 150 mL were prepared. After that, 1000 mL of a 59.2 mg Ll solution of the radical DPPH dissolved in ethanol solution were added. Samples were vortexed and incubated at 20 C for 90 min. The absorbance was measured at 515 nm (UV-Mini 1240 model, Shimadzu Corporation, Japan) and the equivalent mass of florets tissue required to consume 50% of the initial DPPH was calculated (EC50). The antioxidant capacity was expressed as EC50 1 per kilogram. Four replicates were analyzed per type of inflorescence and storage time.