2.1. Materials and chemicals
Senjed (Elaeagnus angustifolia L.) fruit obtained from the traditional market (Azarshahr, Iran) and were separated manually from the peel, then the separated peels were dried in an oven at 40 °C till the constant moisture content of 7.5%. Sesame oil was freshly prepared from a traditional cold-pressed oil manufacture (Azarshahr, Iran). 1,1-Diphenyl-2-picrylhydrazyl (DPPH), gallic acid, (+) catechin 1,1,3,3,-tetramethoxypropane and tert-Butylhydroquinone (TBHQ) were purchased from Sigma Chemical Co. (St. Louis, MO, USA). Folin–Ciocalteau reagent, isooctane solvent and p-anisidine reagent were purchased from E. Merck Co. (Darmstadt, Germany). All other reagents were of analytical grade.