Boiled fresh and frozen broccoli and raw fresh broccoli was hydrolyzed in vitro by simulated gastric fluid. The total phenolics and phenolic acids content of the extracts was determined. Four analytical methods were used for evaluation of the antioxidant activity. The highest content of phenolic acids (0,063 (μg/ml) was obtained in fluid after in vitro digestion of boiled frozen broccoli. The phenolic acids of analyzed samples showed significant antiradical activity (24-34%) and effectively inhibited autooxidation of linoleic acid. Inhibition of β-carotene bleaching was not correlated with total phenolics and phenolic acids content in analyzed samples. Significant correlations (r = 0,89) between total phenolics and phenolic acids content and ability of inhibiting linoleic acid autooxidation was found. The neutralization ability of free radical DPPH• was correlated with total phenolic acids content (r = 0,85).
broccoli, phenolic acids, antioxidant activity