DEFATTED OILSEED MEAL EXTRACTION BY AEROSOL OT/WATER/HEXANE REVERSE MICELLES
Oilseed meals are excellent sources of protein; however, they contain undesirable compounds which are difficult to remove economically. In the present study the reverse micellar system Aerosol OT or AOT (sodium di-2-ethylhexyl sulfosuccinate)/water/hexane was investigated in order to evaluate the possibility of extracting selectively these minor undesirable organic compounds (phenolic compounds, phytic acid and alkaloids) without extracting proteins from defatted soy and tarwi (Lupinus mutabilis) meals.
The variables of the AOT/water/hexane extraction system studied were 1) the water to surfactant molar ratio, wo, from 0 to 35; 2) the concentration of AOT in the micellar solution, [AOT], at 50, 100 and 150 mM; and 3) the type of salt (KCl or NaCl) used in the back transfer aqueous solution. Extraction curves of the phenolic compounds, phytic acid and alkaloids were obtained, and the extraction and recovery (back transfer) curves were obtained for proteins. It was found that wo was a more important parameter than [AOT] in the selective extraction. Proteins and phytic acid showed the highest extraction yields at intermediate levels of wo (10-20), but no selectivity was obtained. Phenolic compounds were extracted in greater quantities at intermediate to high levels of wo (15-35). Alkaloids showed good solubility in AOT/water/hexane reverse micellar system, at low wo (as low as 3) where no proteins were solubilized. It was shown in this study that AOT/water/hexane reverse micelles could be used to remove undesirable components of soy and tarwi defatted meals.