EFFECTS OF FILTRATION THROUGH ACTIVATED CARBONS ON PEROXIDE, THIOBARBITURIC ACID AND CARBONYL VALUES OF AUTOXIDIZED SOYBEAN OIL

Effects of filtration bleaching on peroxide value (PV), thiobarbituric acid value (TAV) and carbonyl value (CV) of autoxidized soybean oil were investigated by using twenty-three kinds of activated carbon in order to improve oil quality. From the decreases in PV, TAV and CV and from the physical and chemical properties of activated carbons, it was suggested that hydroperoxides, aldehydes and ketones were adsorbed on the acid sites distributed over the surface or within the pores of the activated carbons while the autoxidized soybean oil flowed through the packed column. The residual tocopherols in autoxidized soybean oil and treated soybean oil were determined during storage. The decrease in oxidative stability of treated soybean oil seemed to be caused by elimination of alpha-, beta- and gamma-tocopherols. delta-Tocopherol was chemically more stable than alpha-, beta- and gamma-tocopherols in autoxidized soybean oil.