The novel technique of multi-frequency temperature modulated differential scanning calorimetry is employed to measure a decrease in the heat capacity under quasi-isothermal conditions. The effect is used to monitor the kinetics of physical aging in glassy maltitol at similar to 5-8 degrees C below the glass transition temperature. The heat capacity relaxation is analyzed by an isoconversional method that yields effective activation energy for different extents of relaxation. The early stages of aging demonstrate an activation energy similar to 145 kJ mol(-1) that is significantly smaller than the activation energy of alpha-relaxation (413 kJ mol(-1)), which is closely approached at the final stages of aging. (C) 2007 Elsevier B.V. All rights reserved.