Caustic refining in particular does not only effectively perform the separation functions described above but is considered ‘‘more forgiving’’ in operation than alternate physical methods. If the degumming operation has been less than perfect (or is not used), alkali refining will remove the bulk of the phosphatides. If a high amount of metals, particularly calcium and magnesium, are present, these can be removed in the chemical neutralization process.
The edible oil refining processes are degumming or gums conditioning/neutralization, bleaching and deodorization.