ارزیابی و مقایسه خصوصیات فیزیکوشیمیایی، ساختار اسید چرب و پایداری اکسایشی روغن بذر گشنیز و شوید

Identify and cultivate new oil seeds is an important step in the supply of required oil in our country. The aim of the present research was to evaluate the composition of physicochemical properties, fatty acids structure and the oxidative stability of Dill (DS) and Coriander (CS) seed oils. To produce oil, the seeds were mixed with n-hexane solvent in the ratio of 1:4 w/v. The physicochemical properties of DS and CS oils includeding acid value, peroxide value, iodine value, refractive index, wax compound content, viscosity, specific gravity, oxidative stability and fatty acids structure were examined. According to the results, the acid value (11.56 mg/g), iodine value (104 g/100g of oil), wax compound content (34.25%) and specific gravity (0.92 kg/m³) of DS oil was higher than CS oil. Also peroxide value (3.07 meq/kg), viscosity (20.94 cp), refractive index (1.55) and oxidative stability (16.3 h) of CS oil was higher than DS oil. DS oil contained 8.51% of saturated fatty acids that mainly composed of palmitic acid and stearic acid which is lower than CS oil (8.83%). DS oil contained 91.35% unsaturated fatty acids. The ratios of polyunsaturated fatty acids to mono–unsaturated fatty acids of DS and CS oils were 0.23 for both oils. Also the ratio of polyunsaturated fatty acids to saturated fatty acids of DS and CS oils were 2.07 and 1.94, respectively.