Fatty Acid, Total Phenol and Tocopherol Profiles of Some Walnut Cultivars: A Comparative Study

As a member of nuts, walnut is consumed from snacks to salads and desserts to entrees and an importantpart of human diet for centuries. Walnut biological and nutritional value is also enhanced by its valuable protein and rich in nutrient composition such as vitamins and minerals. The most important characteristic of walnut oil is the abundance of polyunsaturated fatty acids, which makes it a unique food because of high amount of linoleic acid. Due to having valuable protein, vitamins and minerals it enhances biological and nourishment value, also. Recent epidemiological studies showed that consumption of walnut reduce cardiovascular diseases due to the rich in antioxidant properties, valuable fatty acids and tochopherols contents. In Turkey, walnut production and consumption increases year by year. The kernel of walnut genotypes shows variability in terms of their fat, fatty acid and tocopherol profiles. In this paper, it was aimed to characterize 10 walnut (Juglans regia L.) cultivars (Bilecik, Chandler, Hartley, Howard, Maras 12, Maras 18, Midland, Pedro, Sen and Serr) based on their fatty acid profiles using GC (Gas Chromatography), tocopherol and its isomers by HPLC (High Performance Liquid Chromatography) and total phenol content with spectrometric methods. Among the walnut cultivars “Hartley” was the highest linoleic acid (64.56%) and “Howard” was the α-linolenic acid 13.26 (%). The highest values of α (38.76 μg/g), β + γ (312.19 μg/g) and δ-tocopherol (40.77 μg/g) and total phenol (349 mg GAE/100 g ext) content were detected in “Sen” cultivar. Obtained results might be significant for further breeding programme to improve rich in especially γ-tocopherol linoleic acids and total phenolic compounds.