Isothermal titration calorimetry (ITC) was used to characterize the thermodynamics of the complexation processes of alpha-, beta- and gamma-cyclodextrin (CD) with ferulate (FER) in aqueous solutions. The equilibrium constants of ferulate complexation with CDs (K-c, in dm(3) mol(-1)) at pH 9.0 and 25.0 degrees C were: 176.5 +/- 5.0 (beta-CD), 53.2 +/- 3.4 (alpha-CD) and 19.4 +/- 0.4 (gamma-CD). Although FER-beta-CD is the tightest complex of the three studied, its binding reaction is also the least exothermic and the only one that is entropically favored. Calculated binding enthalpies, based on the buried surface area upon complexation, are close to those determined by ITC except for the FER-beta-CD complex which is more than two times more exothermic. According to these results and those obtained by molecular docking simulations, it is proposed that ferulate binds to the hydrophobic cavity of beta-CD, displacing more water molecules than in the other two CD complexes. (C) 2016 Elsevier B.V. All rights reserved.