Glass Transitions in Low Moisture and Frozen Foods: Effects on Shelf Life and Quality

摘要

The physical state and phy sicochemical properties of food materials affect their behavior during processing, storage, distribution, and consumption. Although fresh foods have diverse structural characteristics and compositions, their main components are carbohydrates, lipids, proteins, and water. Water interacts primarily with hydrophilic compounds, i.e., carbohydrates and proteins, and to a lesser extent with hydrophobic lipids. Composition of the carbohydrate fraction of foods varies from low molecular weight sugars dissolved in water to cell wall polymers that may be plasticized or softened by water, but may not be water soluble. The protein fraction has a polymeric structure. These materials can be considered to be water compatible biomaterials that may exist in a molecularly disordered, amorphous state, especially in frozen and low-moisture foods.