Kinetics of color changes during hazelnut roasting was described for a temperature range of 100-160 degrees C for 60 min. The rate of color changes was significantly affected by temperature and time over the experimental conditions. Roasted hazelnut samples produced significantly lower L-value and b-value in ground-stale color measurements compared to whole-kernel measurements. The results showed that color changes during hazelnut roasting can be satisfactorily described by a third-degree polynomial with an Arrhenius-type temperature dependence of the model coefficients. Activation energy for the L-value of color was found to be 62.3 kJ/mol over the temperature range of the study. A generalized model for color changes during roasting of hazelnuts as a function of temperature and time was established. (C) 2000 Elsevier Science Ltd. All rights reserved.