Fatty Acid Composition and Tocopherol Content of 13 Walnut Cultivars Grown in China

Walnuts were collected from 13 different cultivars of trees grown in Yunnan, China. Total oil was extracted and analyzed for fatty acid by gas chromatography, tocopherol was analysed by high-performance liquid chromatography. The total unsaturated fatty acid content of the studied cultivars was always higher than 90% and linoleic acid was predominant. The linoleic acid (18: 2) content of the oils ranged from 57.91 to 72.46% and the linolenic acid (18: 3) content ranged from 5.89 to 10.97%. The tocopherol contents of the walnut oils ranged from 0.408 to 0.842 mg/ml. gamma-Tocopherol dominated the profile while a-tocopherol accounted for a small proportion of the total content. The work contributes to knowledge of the nutritional properties of walnut oils.