A comparative study on the antioxidative and anti-allergic activities of fresh and aged black garlic extracts

The antioxidative and anti-allergic activities of fresh and aged black garlic extracts were investigated. The garlic samples were extracted with 70% ethanol (v/v) and the total phenolic content was measured. The antioxidant capacity of extracts was assessed by determining the scavenging activities on 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals, ferricyanide reducing power, ferrous ion-chelating ability and inhibitory effect on linoleic acid peroxidation. The anti-allergic activity of extracts was analysed by measuring their inhibitory effects against beta-hexosaminidase release. The aged black garlic exhibited significantly higher phenolic content and greater antioxidative activity than fresh garlic. Both garlic extracts showed strong antioxidant capacity in a dose-dependent manner. On the other hand, a considerably higher suppression of beta-hexosaminidase release was found in fresh garlic extract at lower concentration compared with that of the black garlic. Results of this study illustrate that ageing of garlic could enhance its antioxidant capacity, but could decrease its anti-allergic activity.