Theoretical Prediction of the Water Activity of Standard Saturated Salt Solutions at Various Temperatures

摘要

ABSTRACTA theoretical approach was used to predict the water activity (aw) at 15°C and 35°C of selected saturated salt solutions used as standards in the range of microbial growth (∼0.57–0.97). For this purpose a rigorous thermodynamic model to predict osmotic coefficient was used. The results agreed very well with experimental measurements at 15°C and 35°C for most salts studied, which included NaBr, NaCl, (NH4)2SO4, KCl, BaCl2, and K2SO4. For KNO3the agreement at the higher temperature was somewhat less satisfactory and the reasons for this behavior are di