Comparison of Tocopherol Contents in Crude and Refined Edible Vegetable Oils and Fats by High Performance Liquid Chromatography

Abstract

On 237 samples for 17 kinds of crude vegetable oils and refined edible oils from them collected from 21 factories in 1980 and 1981, tocopherols in these oils were measured by high performance liquid chromatography under the same conditions as reported previously. Results obtained were as follows:1) For crude oils, liquid oils at room temperature generally had a tendency to be higher contents of total tocopherols than solid ones. Also, the content and composition of tocopherols were found rather specific to the kind of oils, showing a slight dispersion among samples for same kind. In most samples, small amounts of β-tocopherol were detected.2) For refined oils, contents of total tocopherols were generally found 6070% level of those in corresponding kinds of crude oils, while no significant difference of tocopherol compositions was observed between same kinds of refined oils and crude oils.3) For all samples, a positive significant correlation was observed between the content of total tocopherols and the percentage of polyunsaturated fatty acids (C18:2+C18:3), and rapeseed oils showed that the low erucic type, showing higher percentage of polyunsaturated fatty acids, contained more total tocopherols than the high erucic type. However, sunflower and safflower oils, in which α-tocopherol occupied more than 90% of total tocopherols, contained less total tocopherols than soybean and rapeseed oils, although the former showed higher percentage of polyunsaturated fatty acids than the latter.