2011 Volume 18 Issue 1 Pages 25-34
In order to propose effective preparation methods for natural antioxidant food additives, variations in the marker constituents and antioxidative potencies of extracts depending on different extraction methods were estimated. Several extracts were prepared using different solvents from the leaves of Salvia officinalis (Sage), fruits of Foeniculum vulgare (Fennel), and Houttuynia cordata (Dokudami) which are the raw materials of natural food additives. Their antioxidative potencies and marker ingredients were estimated based on the oxygen radical absorbance capacity (ORAC) and HPLC analysis. Among the various extracts prepared from sage, the 50% aqueous ethanolic (EtOH) extract, which contained rosmarinic acid as the major component, showed high antioxidative potency. The EtOH, aqueous EtOH and other extracts of fennel showed antioxidative activities weaker than the other tested materials. The fraction including a volatile oil of fennel showed weak antioxidative activity, therefore it was suggested that the active constituents were contained in the polar fractions. Syringin (sinapyl alcohol 4-O-β-D-glucoside) and quercetin 3-O-β-D-glucuronide were identified as the major constituents of the fennel extract. In the dokudami extracts, the 50% aqueous EtOH extract showed a high antioxidative potency, which was suggested to be responsible for the quercitrin (quercetin 3-O-α-L-rhamnoside) of the major constituent.