Prediction of water activity of glucose and calcium chloride solutions Original Research Article

The water activity (aw) of glucose and calcium chloride solutions in the intermediate concentration range and at temperatures between 20 and 35 °C was determined. It was found that the aw measured at 25 °C 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 hE/R was developed to correlate the effect of temperature on aw for various concentrations of the two solutions as follows: hE/R=−446.52C3+349.34C2−120.92C for glucose, and hE/R=−9561.7C3+2853.8C2−422.4C for calcium chloride solution.