In a previous paper (Bosser and Belin, 1994), it was shown that the co-oxidation of beta-carotene (BC) by xanthine olridase in aqueous solutions at 37 degrees C led to beta-ionone, epoxy-5,6-beta-ionone, and dihydroactinidiolide (DHA). We explain in this article the pathways between the ionone derivatives, and the respective places of each volatile compound in the enzymatic bleaching of BC are discussed. We also propose a simple synthetic way to DHA from commercially available beta-ionone.