The effect of drying temperature on the antioxidant activity of thyme extracts.

Faten H Thamer, Eqbal MA Dauqa

Abstract

This investigation is aimed at studying the influence of different drying temperatures on the antioxidant activity for thyme leaves. In the present study different spectrophotometric methods (DPPH, FRAP) are using to investigate the antioxidant activities of thyme plants. The results showed that the drying temperature influences the antioxidant activity. The antioxidant activity of all studied extracts decreased with increasing temperature attending decreasing in total phenol. Fresh thyme shows the highest antioxidant activity (0.014 BHTE.mL-1, 0.0064 AAE and 0.0062 GAE).mL-1 extract and total phenol content (8.78 10-4 mol GAE and 7.50 10-3 mol AAE).mL-1 of extract. Whereas thyme dried at 40°C show the lowest antioxidant activity, (0.0042 BHTE, 0.0019 AAE and 0.0018 GAE).mL-1 of plant extract and total phenol contents (4.30 10-3 AAE and 4.68 10-4 GAE).mL-1 of plant extract.

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