Cold Pressing and Supercritical CO2 Extraction of Hemp (Cannabis sativa) Seed Oil

In the past few decades, the Cannabis sativa L. hemp variety has been unfairly neglected because of its similarity to the illegal kind Cannabis indica used as a narcotic. The objective of this study was to evaluate the process of oil extraction from Cannabis sativa seeds by cold pressing, followed by extraction with supercritical CO2. In the pressing experiments, the response surface methodology was conducted in order to study the effects of temperature, frequency, and nozzle size on oil recovery and quality parameters. The optimal condition for obtaining the highest oil recovery (23.34 %) and the best oil quality within the experimental range of the variables studied was at temperature of 60 °C, frequency of 20 Hz, and nozzle of ID 6 mm. The residual oil (10.33 %) in the press cake was extracted totally by supercritical CO2 in a newly designed supercritical fluid extraction system. Oregano essential oil was the most effective in protecting the oil from oxidative deterioration.