Optimal process of supercritical carbon dioxide extracting Bama hempseed oil and its physicochemical property

Abstract

The objective of this work was to obtain optimal SC-CO2 extracting BHS oil process, response surface methodology (RSM) was applied to analyze effects of extraction pressure, extraction temperature, CO2 flow rate and extraction time on oil yield. Quality indices, fatty acid compositions and antioxidant activities were further compared between SC-CO2-extracted oil and Soxhlet-extracted oil. The results showed that the maximum recovery of BHS oil was 26.78 ± 2.75% (w/w) when SC-CO2 conditions were extraction pressure of 38.8 MPa, extraction temperature of 36.15 °C, CO2 flow rate of 7.51 L/min and extraction time of 3 h. SC-CO2-extracted BHS oil exhibited better transparency, smell and color as well as higher unsaturated fatty acid content than Soxhlet-extracted oil. Oleic acid, linoleic acid and linolenic acid contents were 12.75 ± 0.90%, 56.51 ± 1.74% and 19.18 ± 2.69%, respectively. Additionally, SC-CO2-extracted BHS oil showed higher iodine value, saponification value and tocopherol, lower acid value and peroxide values as well as stronger antioxidant activity than Soxhlet-extracted oil. In conclusion, RSM was successfully applied for SC-CO2 extraction optimization of BHS oil. SC-CO2 extraction was a better technique to produce higher value BHS oil than traditional Soxhlet extraction.