Using uruguayan pillared clays for bleaching corn oil

Abstract

In the present paper adsorptive capacity to remove carotenes from a corn oil by an Uruguayan montmorillonite modified by different treatments: exchange with Na+ ions (M-Na), acid-activation (Act), exchange with Ca+2 and pillaring with Keggin ions (Pilc-Act), acid-activation and pillaring (Act Pil-Ca), is studied. Bleaching action of the Uruguayan modified montmorillonites is compared with two commercial clays: Tonsil Optimum (Süd-Chemie) and montmorillonite of type K 10 (Aldrich). Our results demonstrate that Act and Pilc-Ca samples are so efficient bleaching clays as commercials but M-Na sample is lower. Also, mixtures of Pilc-Ca with commercial clays, added together in one step or consecutively in two steps, are studied. These procedures do not improved the bleaching action. As conclusion, the modified clay Pilc-Ca allows to bleach a neutralized and degummed corn oil, giving an end product similar to edible commercial oils. Such effect is improved with the simultaneous action with activated clays.