In this work, we determined the stability parameters of bovine beta-lactoglobulin, variant A, (BLG-A), in relation to their transition curves induced by cetylpyridinium chloride (CPC) as a cationic surfactant. The experiments took place over the temperature range of 298 K to 358 K. For each transition curve at any specific temperature, the conventional method of analysis, which assumes a linear concentration dependence of the pre- and post-transition base lines, gave the most realistic values for Delta G(D)(H2O). Results show that the minimum value of Delta G(D)(H2O) occurs at T = 328 K. Using the Gibbs-Helmholtz equation, the values of enthalpy, Delta H-D, and entropy, Delta S-D, of denaturation have been calculated considering temperature dependence of Delta G(D) at any specified concentration of CPC. The values of 12.05 kJ . mol(-1), 18.54 kJ . mol(-1), and 18.32J . mol(-1) . K-1, were obtained for Delta G(D)(H2O). Delta H-D(H2O), and Delta S-D(H2O), respectively. The results show that the enthalpy term dominates the entropy term. (C) 2010 Elsevier Ltd. All rights reserved.