G. Levi et M. Karel, THE EFFECT OF PHASE-TRANSITIONS ON RELEASE OF N-PROPANOL ENTRAPPED INCARBOHYDRATE GLASSES, Journal of food engineering, 24(1), 1995, pp. 1-13
The mobility of an organic volatile probe (1-n-propanol), incorporated
in two types of amorphous carbohydrate glasses, was evaluated by meas
uring probe retention as a function of time. Retention was found to de
pend on temperature, moisture content and the degree of matrix collaps
e. In sucrose glasses, crystallization and probe release occur simulta
neously and both crystallization and release depend on the temperature
above T-g, as predicted by the William-Landel-Ferry (WLF) equation. I
n sucrose:raffinose systems held above T-g, initial rapid release of t
he probe ('fast' release) is observed coinciding with, and presumably
due to, matrix flow during collapse, followed by a much slower diffusi
onal release. Relaxation times for collapse (tau(c)), and 'fast' relea
se (tau(FR)) above T-g were calculated They were found to be dependent
on T-T-g and moisture content. Dependence of relaxation times on (T-T
-g) was found to be well predicted by the WLF equation.