Antioxidant properties of catechins and green tea extracts in model food emulsions

Roedig-Penman, A.; Gordon, M.H.

Antioxidant properties of catechins and green tea extracts in model food emulsions

1997

Roedig-Penman, A. | Gordon, M.H.

Extraction of green tea with hot water provided an extract that was highly effective as an antioxidant for an oil-in-water emulsion at pH 5.5 during prolonged storage (40 days). Other components besides epigallocatechin gallate (EGCG) and epicatechin gallate (ECG) made important contributions to the antioxidant activity of the extract in an oil-in-water emulsion, since ECG, when pure, had no significant antioxidant activity (p > 0.05) and EGCG was completely oxidized within 15 days. Myricetin had a greater antioxidant effect in this system than EGCG or ECG at a concentration of 10(-4) M in the absence of ferric ions, but all three flavonoids exhibited prooxidant effects in the presence of ferric ions.

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