Fresh ginseng roots were aged in an oven at 80°C for 14 d. The in vitro and in vivo antioxidant activities of this aged ginseng, in comparison with those of the white and red ginsengs, were evaluated. In in vitro antioxidant assays, the ethanolic extracts from aged ginseng showed significantly higher free radical scavenging activity and reducing power than those of the white and red ginsengs. In in vivo antioxidant assays, mice were fed a high fat diet supplemented with white, red, or aged ginseng powders. High fat feeding resulted in a significant increase in lipid peroxidation and a substantial decrease in antioxidant enzymes activities in the animals. However, diet supplementation of ginseng powders, particularly aged ginseng, markedly reduced lipid peroxidation and enhanced the antioxidant enzymes activities. The results illustrate that the aged ginseng has greater in vitro and in vivo antioxidant capacity than the white and red ginsengs. The aged ginseng also showed considerably higher total saponin, phenolic, and flavonoid contents, indicating that its antioxidant capacity may have been partly due to its high levels of antioxidant compounds. This new ginseng product may be useful as a functional food with strong antioxidant potential.
Keywords: aged ginseng; antioxidant capacity; antioxidant enzymes; phenolics; red ginseng.