Plasticizing Effect of Water on Thermal Behavior and Crystallization of Amorphous Food Models

TLDR

Dehydrated sugar solutions serve as model systems to study how temperature, moisture, and time affect the thermal behavior of amorphous foods. Glass transition, crystallization, and melting temperatures all decrease with higher moisture; sucrose/fructose mixtures show Tg slightly below the sticky point, and sucrose crystallization is delayed by fructose or starch, with time‑dependent crystallization above Tg following the WLF relaxation model.

Abstract

ABSTRACT Dehydrated sugar solutions were used as models of thermal behavior of amorphous foods, and of the effect of temperature, moisture content and time on physical state of such foods. The transition temperatures determined were glass transition (T g ), crystallization (T cr ) and melting (T m ) which all decreased with increasing moisture. T g of a sucrose/ fructose model had a slightly lower value than the empirical “sticky point,” at all moisture contents studied. Crystallization of sucrose was delayed by addition of fructose or starch. Crystallization above T g was time‐dependent, and the relaxation time of this process followed the WLF equation.