15E-20 |
In vitro and ex vivo antioxidant effect of honey |
N. C. GHELDOF and N. J. ENGESETH. Food Science and Human Nutrition, University of Illinois, 259 ERML, 1201 West Gregory Drive, Urbana, IL 61801 Oxidative stress is believed to play a significant role in the development of many chronic diseases. This has led to considerable interest in health-related effects of diets high in antioxidants. Previous research demonstrated that honeys from various floral sources have protective antioxidant effects in food systems and in vitro assays. The objective of this study was to assess the antioxidant effect of honey in a biologically relevant in vitro system and in the human body in order to determine the potential of honey as a dietary source of antioxidants. In vitro antioxidant capacity of honeys from various floral sources was measured spectrophotometrically by monitoring conjugated diene formation as an index of copper-catalyzed serum lipoprotein oxidation. Acute ex vivo antioxidant effect of consumption of black tea with honey was assessed in a controlled human intervention study. Blood samples were drawn from twenty-five healthy males before consumption, and 60 and 90 minutes after consumption. Plasma antioxidant status was analyzed by ORAC and copper-induced serum oxidizability was measured ex vivo. The inhibitory effect of all honeys on in vitro lipoprotein oxidation was dose-dependent. The concentration of honey producing 50% inhibition of oxidation, ranged from 0.62 g/L (buckwheat honey) to 3.3 g/L (acacia honey), and were all significantly lower than the concentration of sugar analogue (p<0.0001). There was a significant correlation between ORAC values of the honeys and inhibition of lipoprotein oxidation (R2=0.665). Data collected from the human study suggest that consumption of black tea with honey results in a slight increase (10%) of water-soluble plasma antioxidants as measured by ORAC. Lipoprotein oxidation was not altered dramatically by consumption of the different beverages. This research provides primary evidence of the biological potential of honey as a dietary antioxidant, strongly supporting incorporation of honey into the human food supply as a healthy alternative to sugar.
Session 15E, Nutraceuticals & Functional Foods I
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