Cholesterol oxidation in tallow during processing

The oxidation of cholesterol during the bleaching and deodorization process of tallow was studied. Eight polar cholesterol oxidation products were targeted, but only cholest-5-en-3beta,7beta-diol (7beta-HC) and 5beta, 6beta-epoxy-5beta-cholestan-3beta-ol (beta-CE) could be quantified in the samples analysed. The content of 7beta-HC was slightly higher in the processed tallow (0.6-0.7 mug/g) compared with natural tallow (0.2 mug/g). However, the content of beta-CE was considerably increased during processing, ranging from 0.8 to 3.4 mug/g, compared with 0.6 mug/g in the natural tallow. The general observation was that the content of beta-CE was influenced by temperature, duration and type of bleaching earth. (C) 2003 Elsevier Ltd. All rights reserved.