PV was determined according to the Norme ISO 3960 (1977). About 5 g of oil was mixed with 10 ml of chloroform then 15 ml of acetic acid. 1 ml of saturated potassium iodide (KI) was then added. The mixture was kept 5 min in darkness with continuously shaking, and then 75 ml of distilled water were added. Sodium thiosulfate solution (Na2S2O3) 0.01 mol/l was used for titration in the presence of starch solution as indicator until brown coloration disappeared. PV was calculated according to the following Eq.