Co-oxidation of beta-carotene in the presence of linoleic acid was catalysed by potato lipoxygenases. The rate of co-oxidation was dependent on the concentration of both linoleic acid and beta-carotene. The maximum rate of co-oxidation occurs at a molar ratio of linoleic acid to beta-carotene of 16:1. (C) 1998 Elsevier Science Ltd. All rights reserved.