Determination of Fat, Fatty Acids and Tocopherol Content of Several Turkish Walnut Cultivars

In this study, six Turkish local walnut (Juglans regia L.) cultivars grown in the Pozantı district of Adana province of Turkey were characterized in terms of fat, fatty acids, and tocopherols content. Total lipid and fatty acid content were analysed using Gas Chromatography Flame Ionization Technique (GC/FID) while, tocopherol content was analysed by High Performance Liquid Chromatography (HPLC) technique. The total fatty acid levels varied between 62.54% (Yalova-4) to 70.20% (Yalova-2). Three saturated fatty acids were identified and quantified as stearic acid ranging from 1.96 to 3.25%, myristic acid ranging from 0.05 to 0.07% and palmitic acid ranging from 5.98 to 6.84%. As for the unsaturated fatty acids; linoleic acid which a predominant fatty acid (54.13-62.51%), followed by oleic acid (18.82-27.09%), a-linoleic acid (9.83-12.7%), and palmitoleic acid (0.04-0.09%) were detected respectively. In this study, the spectrum of tocopherols comprised three isoforms; α, β, γ were also identified and quantified by HPLC technique. However, δ-tocopherol isoform was not detected. In the all examined walnut cultivars, the total tocopherol content varied from 67.18 (Bilecik) to 173.81 µg/g (Yalova-2). γ-tocopherol, a-tocopherol and β- tocopherol content were found between 61.1 to 164.51 µg/g, 5.43 to 11.53 µg/g and 0.60 to 5.82 µg/g, respectively. Yalova-2 was the most promising cultivar in terms of total oil content and total tocopherol content.