THE USE OF THERMAL-ANALYSIS IN THE DEVELOPMENT OF A BETTER UNDERSTANDING OF FROZEN FOOD STABILITY

Reactions causing deleterious changes in texture, structure and chemic al composition of frozen foods occur frequently and result in a loss o f quality or shelf-life. Polysaccharides, e.g., guar, locust bean gum, are added to many frozen food formulations at low concentrations and are effective at stabilizing products against rapid ice crystal growth . During freezing, an unfrozen phase (UFP) containing a high concentra tion of dissolved solutes is formed as water is separated from solutio n in the form of ice. This UFP is capable of undergoing a glass transi tion at low temperatures. Thermal analysis techniques (DSC, TMA, DEA) have been used extensively in the determination of thermal and physica l properties at subzero temperatures for a number of model systems and frozen foods and in the elucidation of mechanisms of polysaccharide a ction.