Progress in understanding of supplemented state diagrams of hydrophilic food materials

Since decades food scientists have been using supplemented state diagrams for finding the storage conditions for food stability, and for the design of food structuring processes involving phase transitions such as baking. Only, recently thermodynamic theories have been developed allowing for complete prediction of the phase transitions and glass transitions. Interpretation of experimental and numerical results on the state changes of food materials during processing by means of the supplemented state diagram has led to more precise understanding of the physical mechanisms governing optimal processing. In this paper I will review current developments in theory and experiment. More and more work is investigating ternary systems, consisting of a biopolymer, water and a second plasticizer like a carbohydrate. Investigations of their glass transitions indicate multiple glass transitions, suggesting phase separation into biopolymer-rich and plasticizer-rich regions. This has yet to be confirmed by theory. Theory has shown good advancement in the prediction of crystallization/dissolutions of ternary mixtures of two carbohydrates and water.