Kyselka J., Thomes L., Remišová S., Dragoun M., Berčíková M., Filip V. (2016): Preparation of conjugated linoleic acid enriched derivatives by conventional and biphasic isomerisation. Czech J. Food Sci., 34: 511-521.The preparation of conjugated linoleic acid (CLA)-enriched free fatty acids by industrial processes compared with our biphasic isomerisation experiments in a special designed reactor enabling the preparation of CLA esters was evaluated. Our experiments further revealed the main disadvantage of semi-synthetic alkali isomerisation to be the formation of conjugated E,E-octadecadienoic acid isomers (2.92-3.44%) and the bioavailability of free fatty acid products. Urea fractionation technology improved the quality of the reaction mixture, but at the same time the yield of rumenic acid was decreased on purification. Therefore, we decided to apply complexes of noble metals in order to isomerise linoleic acid ester derivatives. The known Wilkinson's hydrogenation catalyst, RhCl (PPh 3 ) 3 , was found to be the most effective. We investigated the preparation of bioavailable CLA-enriched triacylglycerols. Special attention was paid to recycling of Wilkinson's catalyst.