Water Activity-Temperature State Diagram of Amorphous Lactose

摘要

Development in the glass transition temperature,T_g,to reach a stabilized value for amorphous lactose stored at 5,25,and 38 deg C at different water activities varying from a_w=0.21 to 0.59 was followed by differential scanning calorimetry.Combinations of stabilized T_g and water activity were used for interpolation of the value of water activity,where T_g was equal to the storage temperature.These values of water activity were used to construct a state diagram in the(a_w,T)-plane for lactose in the amorphous state from which critical combinations of water activity and storage temperature may be obtained for optimization of storage conditions of lactose-based dry products.