OIL AND ALKALOID EXTRACTION FROM TARWI (Lupinus mutabilis) BY SUPERCRITICAL CARBON DIOXIDE WITH AND WITHOUT ETHANOL AS A COSOLVENT
Tarwi (Lupinus mutabilis) is a legume native to the Andes. It contains 42.6 g/100 g d.w. protein and 18.7 g/100 g d.w. lipids, on average. Tarwi also has 2 g/100 g d.w. toxic alkaloids (mainly lupanine and sparteine) which severely limit its usage. The purpose of this study was to simultaneously extract oil and alkaloids from tarwi seed with ethanol as the cosolvent.
Samples of full-fat ground tarwi seeds were extracted with supercritical carbon dioxide at different temperatures (35oC,45oC,55oC) and pressures (10.3,20.7, 31.0 MPa). Lipid and alkaloid contents of the seeds before and after extraction were determined. Effects of using ethanol at 5% and 10% as a cosolvent on the alkaloid extractions were investigated. It was found that use of cosolvent increased the simultaneous oil and alkaloid extraction to an optimum at 10% ethanol and 10.3 MPa. The results for the use of 5% ethanol showed variations which could be attributed to the occurrence of solute clustering.