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.