Results were reported in note 1 on a simple empirical mathematical model for predicting water activity values (a(w)) in aqueous solutions for extract of mushroom and mushroom creams. In this paper we verified the equation obtained in note 1 on a different raw material (apple creams). Moreover, on the basis of the same method used in the first part of this work a new mathematical model to forecast aw values using two different humectants was proposed. Results showed a high accuracy for the proposed equation. In fact, the correlation coefficients were always greater than 0.994 and the p-levels < 0.001. (c) 2006 Elsevier Ltd. All rights reserved.