Study of glass transition and enthalpy relaxation of mixtures of amorphous sucrose and amorphous tapioca starch syrup solid by differential scanning calorimetry (DSC)

Abstract

Glass transition and enthalpy relaxation of sucrose, glucose syrup solid (GSS) prepared from tapioca starch syrup, and their mixtures (75/25, 50/50, 25/75 sucrose/GSS) have been investigated in terms of Couchman–Karasz equation and Kohlrausch–Williams–Watts model parameters using differential scanning calorimetry data. Addition of glucose syrup solid up to 50% did not significantly increase the mixture’s glass transition temperature compared to the sucrose’s glass transition temperature. Addition of glucose syrup solid into sucrose increased the mean relaxation time τ dramatically at all aging temperatures. In general, the more glucose syrup solid added, the longer the mean relaxation time of the mixture, at the aging temperature that has the same level below its glass transition temperature. Addition of glucose syrup solid into sucrose up to 50% did not change the relaxation susceptibility significantly. Addition of glucose syrup solid into sucrose increased the relaxation time distribution spectrum and generally decreased the β values.