| Phosphatidylcholine, a major phospholipid, has gained special attention the last few decades due to numerous health benefits it provides. The major source of phosphatidylcho line is lecithin, a by-product of the vegetable oil refining process.; In this study, first deoiling of crude lecithin (obtained as the membrane retentate of oil refining process developed at Texas A&M University) has been carried out using supercritical carbon dioxide and/or supercritical carbon dioxide/co-solvent. Presence of either 10% ethanol or 10% acetone in the supercritical fluid made it possible to remove the oil from the crude lecithin at 17.2 MPa and 60°C without any significant coextraction of phospholipids, leaving behind a valuable product. Once the oil was removed, fractionation of phospholipids in order to produce a high-purity phosphatidylcholine was studied. It was shown that 10% ethanol/90% CO2 at 20.7 MPa and 60°C provided 95% selectivity to phosphatidylcholine.; The final stage of this research involved the multicomponent modeling of supercritical fluid extraction of phospholipids using two different models: A mixed flow system taking into account an overall mass transfer coefficient, and a shrinking-core model. Both models seemed to predict the experimental results very well. According to the modeling results, high purity of phosphatidylcholine in the extracts could be attributed to only higher solubility of this phospholipid in the supercritical fluid mixtures of carbon dioxide and ethanol than the solubilities of the other phospholipids in the supercritical fluid mixture. |
