Effect of High Voltage Electrical Pulses on the Oil Yield of Sunflower Meal

Introduction. One of the most important tasks of the modern oil and cake industry is to develop advanced technologies that could increase the yield of high quality oil and related target components from oilseeds. Study objects and methods. The present research featured sunflower oilseeds. The main method of electrical treatment processing was high-voltage electrical pulses of microsecond duration: electric field strength = 13.3 kV/cm, frequency = 30 Hz. To assess the effects of electric pulses, we used disintegration index, i.e. a method of determining the number of destroyed cells according to the electrical conductivity of the material. To assess the effect of the treatment, the sunflower meal was pressed in a hydraulic press. The procedure was followed by extraction using hydrocarbon solvent. As an additional assessment, we analyzed the biomass impedance before and after treatment with high-voltage discharges with the determination of the disintegration index. To assess the quality of the resulting oil, we determined the acid and peroxide values. IR spectroscopy provided a more thorough assessment of the quality of the oil. Results and discussion. After the sunflower meal was treated with high-voltage pulses, the yield of pressed oil increased by 1.9%. The residual oil content in the meal fell down to 0.61% compared with 1.19% in the control samples. Oil quality indicators showed that treatment with high-voltage pulses did not significantly affect the acid value. The sudden change in the peroxide number was probably caused by the prolonged heating during the experiment. Conclusion. The obtained experimental data made it possible to forecast the prospects of using the high-voltage electric pulse for oilseed processing and assess the effectiveness of the technology together with its prospective industrial use. The alternative technology can replace the stage of crushing and pre-heating.