Towards an improved calorimetric methodology for glass transition temperature determination in amorphous sugars

• Published in: CYTA: journal of food Vol. 10; no. 4; pp. 258 - 267
• Main Authors: Saavedra-Leos, M.Z., Alvarez-Salas, C., Esneider-Alcalá, M.A., Toxqui-Terán, A., Pérez-García, S.A., Ruiz-Cabrera, M.A.
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 01-11-2012; Taylor & Francis Ltd
• Subjects: amorphous sugars; azúcares amorfos; Calorimetry; Cooling; degradación térmica; Differential scanning calorimetry; DSC; glass transition; Glass transition temperature; Heat measurement; Heating; Melt temperature; Melting; melting temperature; Methodology; Sugar; temperatura de fusión; Temperature; Thermal degradation; Thermogravimetric analysis; transición vítrea; Transition temperatures
• ISSN: 1947-6337; 1947-6345
• DOI: 10.1080/19476337.2011.639960

Measuring glass transition temperature is necessary for predicting the state and the behavior during the processing, distribution, and storage of many amorphous sugar-rich products. Therefore, the purpose of this study was to establish an improved calorimetric methodology to assess T
g
in amorphous sugars. This method was created through melting crystal with differential scanning calorimetry (DSC) using the same principle proposed by Jiang, Liu, Bhandari, and Zhou (
2008
. Impact of caramelization on the glass transition temperature of several caramelized sugars. Part I: chemical analyses. Journal of Agricultural and Food Chemistry, 56, 5138-5147). Thermogravimetric analysis with simultaneous DSC was required to characterize the melting and thermal degradation temperatures of sugars. Thermograms showing the complete process of heating-cooling-reheating are proposed to determine the precise glass transition temperature during cooling (T
gC
) or reheating (Tg
H
), and to verify if the processed amorphous samples were created with or without thermal degradation. The melting temperature has little effect on the T
g
value whereas the sugar was melted without thermal degradation. Thus, using this methodology the precise T
g
value of amorphous sugars can be determined.