Extraction technique and free radical scavenging activity of flavonoids prepared from Ling Jujube

Reflux extraction technique and free radical scavenging activity of flavonoids of ling jujube were investigated. Optimum conditions were as follows :ratio of liquid to solid 30 ∶1 (mL/g ) ,extraction time 2h , extraction temperature 75℃,75% of ethanol concentration,under the optimal conditions,flavonoids yield of ling jujube flavonoid was 5.01mg/g ,three kinds of in vitro antioxidant system (reducing power ,hydroxyl radical scavenging,and DPPH radical scavenging) results showed that flavonoid had different degree of antioxidant effects in different parts of ling jujube. the result showed a concentration-dose effect,in different concentration range,free radical scavenging activity of flavonoids from different parts of ling jujube was:flavonoids in the pulp flavonoids in entire Ling jujube flavonoids in the pit flavonoids in the peel,these results showed there were high activity or concentration flavonoids in ling jujube pulp,but free radical scavenging activity of different part of ling jujube were all lower than that of ascorbic acid.