2004 年 50 巻 2 号 p. 97-102
To obtain the basically knowledge of the molecular mobility of low molecular carbohydrate under the glassy state, the enthalpy relaxation time of all gluco-di-saccharides and glycosyltrehaloses were examined through aging experiment by using DSC. The glassy samples were aged at several temperatures of (Tg-10)K to (Tg-40)K. The enthalpy relaxation time at each temperature was obtained by fitting Kohlrausch- Williams- Watts equation to the time course of enthalpy relaxation amount (ΔH). When the temperature dependence of molecular mobility was assumed as Arrhenius process, the activation energy amount (ΔE) could be estimated. In tested gluco-disaccharide, trehalose and isotrehalose were most highest Tg, and neo trehalose was the lowest, and the difference with the trehalose was 46K. Furthermore, the ΔE was larger in order to trehalose, isotrehalose>> laminaribiose, cellobiose> maltose> kojibiose, sophorose, nigerose, isomaltose, gentibiose>> neotrehalose. Tg and ΔE of glycosyltrehaloses were higher than maltooligo-saccharides. These results supported the explanation of availability of glassy trehalose and glycosyltrehalose as lyoprotectant of protein or biosystem under the severe circumstance.