Processing of vegetable oils using polymeric composite membranes

A study was conducted to process crude soybean and rapeseed oils using polymeric composite membranes without the addition of organic solvents. The membranes selectively rejected phospholipids, color pigments and certain oxidation products while permeating tocopherols. The color reduction in soybean oil permeate ranged from 74 to 80%. The reduction of oxidation products varied between 50 and 87%. The UV spectra suggested that certain undesirable oxidation changes occurring during the conventional process were eliminated. The increase in the tocopherol content in the permeate ranged between 12 and 15%. The long-term experiments (97 days) indicated good membrane stability. However, the membrane process does not seem to separate free fatty acids from triglycerides and the permeate flux also needs to be improved. (C) 1998 Elsevier Science Limited. All rights reserved.