Mass Balance Model for Enthalpy of Water Binding by a Mixture

摘要

ABSTRACTA thermodynamic approach was based on sorption data over a wide range of water activity (aw) at each of three temperatures. The hypothesis tested was the total partial enthalpy change for the water of a mixture is equal to the sum of the partial enthalpy changes for the water of the individual ingredients at the same aw. This was tested with sorption data for starch, casein, sucrose, starch:casein (1:l) and starch:sucrose (9:l) at 7.2, 20 and 30°C. Experimental values for the starch:casein mixture were in agreement (±5) with those calculated from data on the individual ingredients, validating the hypothesis for a mixture of polymers. The starch:sucrose indicated a greater variation as the sucrose concentration increased to saturatio