Effect of harvest date on the total phenolic compounds and antioxidant activity in Carthamus caeruleus L extracts

The effect of harvest date on Total phenolic compounds and antioxidant activity in Carthamus Caeruleus L roots (a plant used traditionally in Algerian medicine against burns) after solvent extraction by ASE (Accelerated solvent extraction) was determined. The roots were harvested at three different dates (December 2012, May 2013 and December 2013), dried and stored under 25 °C at dark room, the extracts were obtained using Ethanol as solvent. The total phenolic compounds were determined using a modified version of Folin-Ciocalteau method and the antioxidant activity was assessed by Diphenyl-1-Picrylhydrazyl (DPPH) free radical scavenging activity. The results indicated that the total phenolic contents (TPC) were increased for the late harvested roots (May 2013, December 2013), However, the results for the TPC of the harvested roots on December 2012 were situated between the results shown for the late harvested roots this may result from climate during December 2012 which gave a better roots quality in terms of TPC, Similar trends were observed in the antioxidant activity. Therefore, Carthamus Caeruleus L can be harvested later for the optimization of the antioxidant activity that affects significantly the healing power of the plant.