Water extracts prepared from seven varieties of olive leaves native to the Mediterranean area but planted in Sichuan province, P.R. China, namely Frantoiao, Leccio, Ezhi, Picholine, Pendollino, Chenggu and Huaou 9#, w...Water extracts prepared from seven varieties of olive leaves native to the Mediterranean area but planted in Sichuan province, P.R. China, namely Frantoiao, Leccio, Ezhi, Picholine, Pendollino, Chenggu and Huaou 9#, were examined for their total phenonic and flavonoid contents, antioxidant capacity. Total phenolic and flavonoid content were measured by Folin-Ciocalteu method and a colorimetric method, respectively. ABTS＋ method and FRAP were used for examining antioxidant activity. Response surface methodology （RSM） was used for optimizing the extract condition. Under the optimum condition, the total phenolic and flavonoid content of aqueous extracts of the dry olive leaves （DOL） ranged from 40.27 to 56.58 mg gallic acid （GAE）/g DOL and 21.59 to 33.72 mg catechin （CE）/g DOL in June, 34.31 to 52.81 mg GAE/g DOL and 17.11 to 23.53 mg CE/g DOL in November. The ABTS＋ method and FRAP ranged from 0.23 to 0.35 mmol trolox （TE）/g DOL and 313.01 to 409.69 μmol Fe2＋/g DOL in June, 0.19 to 0.30 mmol TE/g DOL and 254.69 to 418.10 pmol Fe2＋/g DOL in November. Our results revealed that the total phenolic and flavonoid, or antioxidant capacity of the water extract were higher in June than November. Moreover, it was noticed that the antioxidant activity depends on the flavonoid and phenolic.展开更多
文摘Water extracts prepared from seven varieties of olive leaves native to the Mediterranean area but planted in Sichuan province, P.R. China, namely Frantoiao, Leccio, Ezhi, Picholine, Pendollino, Chenggu and Huaou 9#, were examined for their total phenonic and flavonoid contents, antioxidant capacity. Total phenolic and flavonoid content were measured by Folin-Ciocalteu method and a colorimetric method, respectively. ABTS＋ method and FRAP were used for examining antioxidant activity. Response surface methodology （RSM） was used for optimizing the extract condition. Under the optimum condition, the total phenolic and flavonoid content of aqueous extracts of the dry olive leaves （DOL） ranged from 40.27 to 56.58 mg gallic acid （GAE）/g DOL and 21.59 to 33.72 mg catechin （CE）/g DOL in June, 34.31 to 52.81 mg GAE/g DOL and 17.11 to 23.53 mg CE/g DOL in November. The ABTS＋ method and FRAP ranged from 0.23 to 0.35 mmol trolox （TE）/g DOL and 313.01 to 409.69 μmol Fe2＋/g DOL in June, 0.19 to 0.30 mmol TE/g DOL and 254.69 to 418.10 pmol Fe2＋/g DOL in November. Our results revealed that the total phenolic and flavonoid, or antioxidant capacity of the water extract were higher in June than November. Moreover, it was noticed that the antioxidant activity depends on the flavonoid and phenolic.
