Frozen State Transitions of Sucrose-Protein-Cornstarch Mixtures

Abstract

ABSTRACT: State transitions of solutions of mixtures of sucrose, albumen, gelatin, and cornstarch were studied using differential scanning calorimetry, and state diagrams were established. Maximum freeze concentration was achieved by annealing of solutions at a temperature T′m of−1°C. The onset temperatures of glass transitions of maximally freeze-concentrated solutes, T′m, were lower and onset temperatures of ice melting, T′g, were higher for mixtures of sucrose, proteins, and cornstarch when compared with those of pure sucrose. Solute concentrations in the maximally freeze-concentrated phase, C′g, were 80% and 81% for sucrose and sucrose/albumin, respectively. The C′g of sucrose/gelatin, sucrose /cornstarch, and sucrose/cornstarch/gelatin was 76%. The state diagrams established with experimental and predicted Tg values are useful for characterization of thermal phenomena and physical state of carbohydrate-protein mixtures at various water contents.