Pressurized liquid extraction of radish seed oil using ethanol as solvent: Effect of pretreatment on seeds and process variables

In this study the use of pressurized ethanol to extract oil from radish seeds was investigated. The influence of the pretreatment of the seeds and the ethanol flow rate, static time, temperature and pressure applied during the extraction was evaluated to determine the effect on the yields of oil and active compounds. The application of thermal treatment after immersion promoted an increase in the oil yields. An ethanol flow rate of 3 mL min(-1) and a static time of 10 min increased the oil diffusion. The extraction at 150 degrees C provided a high oil fraction and higher yields of phytosterols and gamma-tocopherol were obtained at 135 degrees C. In addition, 5 MPa was sufficient to achieve an oil yield of 36.6%, as higher pressures did not influence the process. The oil obtained was rich in oleic and erucic acids, with low acidity and high oxidative induction time.