A model is developed in this work to calculate the interfacial energy and growth activation energy of a crystallized substance from induction time data without the knowledge of the actual growth rate. Induction time data for a L-glutamic acid measured with a turbidity probe for various supersaturations at temperatures from 293 to 313 K are employed to verify the developed model. In the model a simple empirical growth rate with growth order 2 is assumed because experiments are conducted at low supersaturation. The results indicate for a L-glutamic acid that the growth activation energy is 39 kj/mol, which suggests that the growth rate of small nuclei in the agitated induction time experiments is integration controlled. The interfacial energy obtained from the current model is in the range of 5.27.4 mJ/m(2), which is slightly greater than that obtained from the traditional method (t(i)(-1) proportional to f) for which the value is in the range 4.1-5.7 mJ/m(2). (C) 2016 Elsevier B.V. All rights reserved.