A Method for Estimating Glass Transition Temperature of Powders by Discoloration of Betanin under Temperature-programmed Heating Conditions

Abstract

A simple and cheap method for estimating the glass transition temperature (T_g) of powders was proposed. This involved measuring the discoloration process of a dye added to the powders under temperature-programmed heating conditions. The method was applied to evaluate the T_g values of mixtures of maltodextrin and fructose, containing betanin, a natural dye. The T_g values obtained by this method almost agreed with those calculated by the Couchman and Karasz equation using the T_g values for constituents in the mixture, thus indicating the validity of the method.