Chapter 10 : Water Activity in Foods
Résumé
This chapter focuses on the role of water in the physical stability of foods with an emphasis on texture stability of foods with an emphasis on texture (i.e. crispness, softness, stickiness) and structure characteristics (i.e. crystallization, caking, collapse, etc.) of the products. The efficiency of water as a plasticizer is based on water's affinity for other molecules and its ability to form a homogeneous mix without phase separation. The consequence of water plasticization on the material's mechanical properties has often been compared with the plasticization resulting from a temperature increase. Because the physical stability may affect several time‐scales, an optimal control of the humidity will be required during processing, handling, transportation, storage, and consumption. When the effects of water cannot be overcome by the product's composition, technological solutions may lay in the design of moisture barriers or by a strict control of the temperature.