The water activity (a(w)) of glucose and calcium chloride solutions in the intermediate concentration range and at temperatures between 20 and 35 degreesC was determined. It was found that the a(w) measured at 25 degreesC was in accordance with previous studies and fitted the Norrish's model well. However, temperature was found to have a more pronounced effect on aw of solutions at higher concentrations. A polynomial equation for VIR was developed to correlate the effect of temperature on a(w) for various concentrations of the two Solutions as follows: h(E)/R = -446.52C(3) + 349.34C(2) - 120.92C for glucose, and h(E)/R = -9561.7C(3) + 2853.8C(2) - 422.4C for calcium chloride solution. (C) 2002 Elsevier Science Ltd. All rights reserved.