The present invention relates to the manufacture of conjugated linoleic acid, and in particular, to dietary supplements, feeds and food products containing conjugated linoleic acid. Accordingly, processes for producing conjugated linoleic acid of high purity and acid value are disclosed. These processes utilize alcoholate catalysts and esters of sunflower oil, safflower oil, or corn oil as the source of linoleic acid. The esters of conjugated linoleic acid produced by the process can be used in animal feeds and in food products suitable for human consumption. Furthermore, the esters can be converted into free fatty acids or incorporated into triglycerides.