There is provided a process for reducing the free fatty acid content of
natural oils by contacting the crude natural oil with a solvent to
produce an oil product phase substantially depleted in free fatty acids
and a free fatty acid rich solvent phase containing the extracted free
fatty acids and some of the glycerides, and processing the free fatty
acid rich solvent phase with a membrane to recover the glycerides from
the solvent phase, comprising the steps of: (a) contacting the crude
natural oil with an immiscible solvent; (b) separating the deacidifed
natural oil phase from the solvent phase; (c) providing a selectively
permeable membrane having a first surface and a second surface; (d)
transferring a portion of the solvent and a portion of the free fatty
acids and a lesser portion of the glycerides from the first surface to
the second surface across the membrane by contacting the free fatty acid
rich solvent phase with the first surface, wherein the pressure at the
first surface is greater than the pressure at the second surface, and
wherein the membrane is a selectively permeable membrane such that the
membrane rejections of the free fatty acids (RFFA) and glycerides (RGLY)
are greater than 0%, and the membrane rejection (RGLY) of the glycerides
is at least 5% greater than the membrane rejection (RFFA) of the free
fatty acids.