physicochemical properties and stability of oil extracted from three canola cultivars grown in golestan province of iran

the oil extracted from three major canola cultivars (hyolla401, hyolla420 and rgs003) grown in golestan province was analyzed for physico-chemical properties, fatty acid composition, minerals content, and stability during 16 weeks of storage. according to the results, the highest iodine value and refractive index belonged to hyolla401. the highest saponification value was observed in hyolla420. there was no significant difference (p< 0.05) between the relative densities of the three cultivars. study on the mineral content showed the highest level of iron and phosphorus in hyolla420 and the maximum sulfur content in rgs003 cultivar. oleic acid (ω-9) was the major fatty acid in all cultivars and the highest level was found in rgs003 (include % of oleic acid here). the highest level of essential fatty acids, linoleic acid (ω-6) was found in hyolla420 and linolenic acid (ω-3) in hyolla401. in all three cultivars, erucic acid content was low and within the permitted level (include % of oleic acid here). the hyolla420 had the highest content of free fatty acid, acid value, peroxide value, anisidine value and totox value compared to the other cultivars, during storage. however, result of oil stability based on rancimat test showed that the hyolla420 cultivar had the highest induction time during storage, which was in agreement with its low polyene index (pi).