2.2.2 Determination of antioxidant capacity and total phenolic content
Radical- scavenging activity of Camelina seed was detrmined by 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH) assay according to Hanato et al., 1998 method. In short, the different concentrations of methanol extraction (2ml) were added to the 200µM DPPH solution. The mixture was incubated in room temperature for 30 min. The absorbance value of solution was determined at 517nm using Shimadzu UV- Vis spectrophotometer, Japan. The standard curve of Trolox was prepared for the measurement of antioxidant capacity.
The total phenolic (TPC) content was measured by the Folin-Ciocalteu method (Velioglu etal., 1998). In short, the TPC was extracted from seeds (0.1 gr powder) with 10 ml 80% methanol at 70°C for 3h. 2.5ml of Folin-Ciocateu reagent was added to 0.5 ml methanolic extract and incubated in room temperature for 10 min and centrifuged in 5000 rpm for 20 min. Supernatant was incubated at 90°C for 5min when 2.5 ml Na2Co3 solution (7.5%) was added. The absorbance value of mixture read at 765 nm and TPC was determined by a standard curve of Gallic acid.