Supercritical extraction of sunflower oil: A central composite design for extraction variables

Supercritical carbon dioxide (SC-CO2) extraction of sunflower seed for the production of vegetable oil is investigated and compared to conventional methods. The effects of extracting variables, namely pressure, temperatures, particle size, SC-CO2 flow rate and co-solvent, on SC-CO2 extraction are investigated. The maximum yield for sunflower oil is found to be about 54.37 wt%, and is obtained when SC-CO2 extraction is carried out at 80 degrees C, 400 bar, 0.75 mm particle and 10 g/min solvent flow with 5% co-solvent. A central composite design is used to develop the model and also to predict the optimum conditions. At optimum conditions obtained based on desirability function, 80.54 degrees C, 345 bar, 1.00 mm, 10.50 g/min and 7.58% ethanol, SC-CO2 extraction has performed and found that extraction yield dropped by 2.88% from the predicted value. Fatty acid composition of SC-CO2 and hexane extracted oil shows negligible difference and found high source of linoleic acid. (C) 2015 Elsevier Ltd. All rights reserved.