Physical Chemistry of Foods

FIGURE16.2 Illustration of the glass transition, as compared to a melting/
crystallizing transition, of a pure nonpolymeric substance. The solid curves indicate
equilibrium, the broken ones nonequilibrium states. (a) Specific volume (e.g., in
m^3 ?kg
^1 ) as a function of temperatureT. (b) Apparent viscosityZa. (c) Heat
(enthalpy) flow or effective specific heat; the positive direction signifies an
endothermic change during temperature increase.Tgindicates glass transition,Tm
melting/crystallization. Only meant to illustrate trends.