We have studied the effects of prehydration and enzymatic pretreatment of vanilla beans by three cellulolytic enzyme products: Crystalzyme PML-MX, Zymafilt L-300 and Novozym. Vanilla beans were cut in pieces and hydrated in water and with 5% ethanol up to 72 h and reducing sugars and glucose were measured. Prehydration conditions (5% ethanol at 48 h) were used for the study of the effect of pH and temperature on the kinetics of vanillin liberation during 26 h of treatment. Finally, the most adequate conditions of enzymatic pretreatment of each preparation were applied to vanilla beans submitted to the process of vanillin ethanolic extraction showing that enzymatic pretreatment enriches and can as much as double vanillin content in the extract. (c) 2006 Elsevier Ltd. All rights reserved.