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Amorphous state and delayed ice formation in sucrose solutions
Author(s) -
ROOS Y.,
KAREL M.
Publication year - 1991
Publication title -
international journal of food science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.831
H-Index - 96
eISSN - 1365-2621
pISSN - 0950-5423
DOI - 10.1111/j.1365-2621.1991.tb02001.x
Subject(s) - differential scanning calorimetry , glass transition , amorphous solid , crystallization , sucrose , thermodynamics , viscosity , amorphous ice , annealing (glass) , chemistry , materials science , mineralogy , crystallography , polymer , food science , organic chemistry , physics
Summary Phase transitions of amorphous sucrose and sucrose solutions (20–100% sucrose) were studied using differential scanning calorimetry, and related to viscosity and delayed ice formation. Glass transition temperature (Tg) was decreased by increasing water content. Ice formation and concurrent freeze concentration of the unfrozen solution increased apparent Tg. Tg could be predicted weight fractions and Tg values of components. Williams–Landel‐Ferry (WLF) relation could be used to characterize temperature dependence of viscosity above Tg. Crystallization of water above Tg was time dependent, and annealing of solutions with less than 80% sucrose at –35°C led to a maximally freeze‐concentrated state with onset of glass transition at –46°C, and onset of ice melting at ‐34°C. The state diagram established with experimental and predicted Tg values is useful for characterization of thermal phenomena and physical state at various water contents.