Prediction Approach to the Glass Transition Temperature of Amorphous Carbohydrate Polymer

摘要

Most of carbohydrate polymers exist, at least partially, in an amorphous state, and thus, glass transition occurs during dehydration/rehydration and cooling/heating processing. Since various physical properties are changed drastically by the glass transition (Levine and Slade 1988; Roos 1995; Le Meste et al. 2002), it is important to understand the glass transition temperature (T_g). Inulin is a natural carbohydrate polymer that is linked by β(2-1) glycosidic bonds and contains either a terminal β-D-fructose or an α-D-glucose. Chicory root, asparagus, and onions contain a large amount of inulin. The degree of polymerization (DP) of inulin is usually 2-60 units with an average DP =12. Inulin has attracted much attention in the food and pharmaceutical industries for its multiple benefits, such as dietary fiber, prebiotic nature, and fat-mimetic material. Although there have been many efforts to understand the glass transition properties of amorphous inulin, the published data were limited for prediction of T_g (Hinrichs et al. 2001; Zimeri and Kokini 2002; Ronkart et al. 2009). In this study, the T_g of various types of amorphous inulin was investigated using differential scanning calorimetry (DSC), and an empirical T_g prediction of inulin was proposed.