Membrane degumming of crude soybean and rapeseed oils

Membrane separation in edible oil processing is a potential area for energy savings. However, technical and operating‐cost‐related barriers have impeded the successful application of membrane separation in food processing. Studies were undertaken with soybean and rapeseed oils in a magnetically stirred flat‐membrane batch cell with two types of composite polymeric membranes at 3 MPa pressure and at a constant temperature of 40°C. The membranes were NTGS‐1100 and NTGS‐2100, and used silicon as the active layer and polysulfone and polyimide as support layers, respectively. The membrane selectively rejected phospholipids, the content being less than 240 mg/kg in the permeate without any pretreatment or dilution of crude oil with organic solvent. Long‐term studies up to 97 days with soybean oil at two different pressures, 2 and 3 MPa, showed that the rejection of phosphatides was above 96% in most permeates. The permeate flux remained nearly constant but must be improved.