Comparison of sesame oil properties obtained from cold press and solvent extraction methods with refined oil during storage

Considering the importance of the edible oils in the diet and the increasing demand for row and unprocessed oils, in this research the chemical properties of oils obtained from the cold press and solvent extraction of three different varieties of sesame seed including fatty acids composition, chlorophyll, carotenoids, sterol, tocopherol and aflatoxin values were determined. The peroxide value of oils in two conditions of thermal accelerated and optical oxidation was also compared. The results indicated that the extraction efficiency was the highest by using solvent for extraction (58.13%) and oleic acid and linoleic acid are the predominant fatty acids in sesame. There was a significant difference in total sterol, chlorophyll and carotenoid contents of oils extracted by cold pressing, solvent extraction and refined oils (P <0.05). The highest and lowest levels of total tocopherol were related to solvent extracted and refined oils, which were equivalent to 759.18 and 437.4 mg/kg, respectively. The peroxide value increased in accelerated light and temperature conditions over time, and the effect of light on the increasing of the peroxide value was higher than the temperature. The amount of aflatoxin in the extracted oil samples was below the detection limit (ppb 0.01). The results showed that the oils produced by cold pressing methods contain more micronutrients and antioxidants than the refined oils but have shorter shelf lives in unfavorable conditions.