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-3β,7β-diol (7β-HC) and 5β, 6β-epoxy-5β-cholestan-3β-ol (β-CE) could be quantified in the samples analysed. The content of 7β-HC was slightly higher in the processed tallow (0.6–0.7 μg/g) compared with natural tallow (0.2 μg/g). However, the content of β-CE was considerably increased during processing, ranging from 0.8 to 3.4 μg/g, compared with 0.6 μg/g in the natural tallow. The general observation was that the content of β-CE was influenced by temperature, duration and type of bleaching earth.