Removal of nonhydratable phospholipids from soybean oil

Abstract

AbstractOn the basis of the literature concerning the chemical and physicochemical properties of phosphatidic acid and phosphatidates, an experimental investigation of the conditions under which nonhydratable phospholipids (Mg/Ca‐phosphatidates) are removable from water degummed soybean oil was carried out. The experiments were carried out by mixing water‐degummed oil at different fixed pH values with buffer solutions with and without admixture of Ca++, Mg/Ca‐binding reagents and surfactants. The results indicate that the nonhydratable phospholipids can be removed in a chemically nonconverted state as a component of micelles or of mixed emulsifiers. Furthermore, the nonhydratable phospholipids are removable by conversion into dissociated form, i.e., by removal of Mg and Ca from the phosphatidates, which can be accomplished by acidulation or by treatment with Mg/Ca‐complexing or Mg/Ca‐precipitating reagents. Alkali‐refining experiments have shown that removal or chemical conversion of the nonhydratable phospholipids result in reduced emulsion formation and in improved separation of the deacidified oil from the emulsion layer and the soapstock.