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Authors: | X. Gao, M. Uggla, K. Rumpunen |
Keywords: | ascorbic acid, boiling, drying, FRAP, microwave heating, Rosa, rose-hip |
DOI: | 10.17660/ActaHortic.2005.690.36 |
Abstract:
Rose hips are rich in several phytonutrients of which many act as powerful dietary antioxidants.
We investigated effects of temperature during drying and extraction on the total antioxidant activity (FRAP) in water and ethanol extracts of Rosa dumalis rose hips.
Freeze-drying and drying at 50°C and 75°C appeared to preserve the antioxidant activity of rose hips at a high level.
Degradation of antioxidant activity and ascorbic acid in water extracts was prevented by boiling for 2 and 10 minutes, and by microwave heating for 2 minutes.
We also found that the decrease in total antioxidant activity occurring in extracts kept at ambient temperature was probably caused by enzymatic oxidation.
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