Glass transition temperatures amorphous trehalose

The glass transition temperature of trehalose is reported to be approximately 120°C (anhydrous amorphous phase). 

The effect of physical aging on the crystallization state and water vapor sorption behavior of amorphous non-solvated trehalose was studied [91]. It was found that annealing the amorphous substance at temperatures below the glass transition temperature caused nucleation in the sample that served to decrease the onset temperature of crystallization upon subsequent heating. Physical aging caused a decrease in the rate and extent of water vapor adsorption at low relative humidities, but water sorption could serve to remove the effects of physical aging due to a volume expansion that took place in conjunction with the adsorption process. 

Table 1.6.1 Glass transition temperature Tg and crystallization temperature Tc for amorphous sucrose, trehalose, lactose, raffinose and amorphous sucrose in the presence of absorbed water...

A. Simperler, A. Komherr, R. Chopra, W. Jones, W. D. S. Motherwell and G. Zifferer. The glass transition temperatures of amorphous trehalose-water mixtures and the mobility of water An experimental and in silico study. Carbohydr. Res. 342, 2007, 1470-1479. 

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