Bleaching of refined cottonseed oil with modified alumina adsorbents

Abstract

AbstractActivated aluminas, modified by treatment with inorganic and organic acids were tested for their efficiency as bleaching agents and for their ability to eliminate the response of refined cottonseed oil to the Halphen test. The best of these adsorbents, an alumina containing catalytic amounts of adsorbed sulfurous acid, is a bleaching agent that is effective in removing problem pigments from offcolored cottonseed oils, and is superior to activated aluminas in removing green chlorophyll‐like pigments. Oils bleached with the catalytic adsorbent are negative to the Halphen test, and are free of sulfur.Study of the rate of reduction in the Halphen test response as a function of bleaching time and temp indicated that sulfurous acid treated alumina has a pronounced catalytic effect. The Halphen test response is eliminated during a 30 min bleaching period at 225C. Deodorization conditions employed had little effect on Halphen test reduction.