Oak oil is a rich source of essential fatty acids and active compounds such as tocopherols, polyphenols and sterols, which can be very effective in order to prevent many diseases such as cardiovascular disease and cancer. Oak oil could also provide antioxidant activities. Most of the studies are focused on how to produce oak oil with higher quality, and using more innovative and efficient techniques. In this study the combinatory effects of two high voltage electric field treatments and ultrasonic waves on efficiency of extraction of oak kernel oil and physicochemical characteristics of the extracted oil were eva‎luated. Practical experiments and statistical analyses of the inferred results (with a factorial experiment in the form of a compeletly randomized design), such as the time of applying electric field at a voltage of 10.5 kV / cm for 5 minutes and applying ultrasound with power 300 watts with energy consumption of 7.625 watts per hour for 5 minutes was considered as the optimal points. The intended variables including the time and the voltage at the first time and then the applied voltage had the greatest effect on the efficiency of oil extraction. The amount of fat, fiber, moisture, ash and protein percent of oak kernel were calculated as 8.63, 1.28, 2.6, 1.4, and 3.32% by weight, respectively. Using of combining of two the treatments of electric field and ultrasound in the voltage of 10.5 kV and the power of 300 watts increased the efficiency of oil extraction to 4.24 units and 156.45% in compared to the control sample. By investigating of physicochemical properties of extracted oil, it was observed that the using of those treatments had no significant effects on the refractive index, specific gravity, saponification number and a* index of oil color. but its effect on peroxide number, unsaponifiable number, iodine number and indices L* and b* of oil color were significantly and peroxide and the unsaponifiable number were increased, the iodine number was decreased but the indices of the oil color was increased. Physicochemical properties of extracted oil under the optimal conditions including coefficient fracture 1.47, specific gravity at indoor temperature 0.911, the iodine number 96.63 mg per a piece gram of oil, the index 9.98 meqO2 of active oxygen per 1000 g of oil, the unsaponifiable index was 77.25%, and the color indices a* L*, and b*, were calculated 12.67, 11.51 and 21.84 respectively. Finally the result it can be concluded that the use of electric field / ultrasound can be used as a suitable treatment in the oil extraction industry. Key words: oak oil, oil extraction, electrohydrodynamic, high voltage electric field, ultrasound.

جواد كرامت، ناصر همدمي

اميرحسين گلي

هاجر شكرچي زاده، احمد ميره اي