Few studies have looked at the isomeric profile and micellarization of beta-carotene (BC) isomers in green vegetables. Therefore, the aims of the present study were, first, to assess the isomeric profile of BC isomers in raw and cooked vegetables namely broccoli, kale, spinach and Savoy cabbage and, second, to examine the impact of boiling on the BC isomeric profile of the vegetables, their respective micelle fractions and on efficiency of micellarization. All vegetables were subjected to an in vitro digestion procedure. All-trans-, 9-cis- and 13-cis-BC were present in the four vegetables tested. BC isomerization occurred following the cooking of spinach and, to a lesser extent, Savoy cabbage. The isomeric profile of the micelle fractions from broccoli and spinach altered as a result of cooking, but not kale and Savoy cabbage. Our findings suggest that the food matrix may play a role in the effects of cooking on BC isomerization. (C) 2010 Elsevier Ltd. All rights reserved.