Technological conditions and antioxidant activities of the flavonoid extracted from rose and rose residue

Selecting rose residue as the research object, compared with rose, the optimal flavonoid extraction conditions of ethanol extraction were obtained by Orthogonal Test, on the basis of one factor tests. Antioxidant activities were tested, using crude extract lyophilized power. The optimal condition of rose and rose residue ethanol extraction were ethanol concentration 45%, liquid to solid ratio (g/g) 60∶1, temperature 30℃, extraction time 30 min. Under this condition, flavonoids from rose and rose residue were respectively (4.71±0.07) mg/g and (2.31±0.08) mg/g. Antioxidant activities of rose residue were investigated with the method of scavenging·OH, ABTS+· and DPPH·. IC50 was calculated. Results indicated that the flavonoid extract from rose residue had antioxidant activities as well as that from rose. Orders of these three free radical-scavenging activities was·OH-scavenging activity>ABTS+·-scavenging activity>DPPH·-scavenging activity.