Melting and glass transitions of low molecular weight carbohydrates

✍ Scribed by Yrjö Roos

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 674 KB
• Volume: 238
• Category: Article
• ISSN: 0008-6215
• DOI: 10.1016/0008-6215(93)87004-c

✦ Synopsis

Glass-transition

temperatures at various water contents (TJ and in maximally freeze-concentrated solutions (T,'), fusion temperatures (melting points, T,), and heats of fusion (Aff,) were determined for pentoses, hexoses, disaccharides, and alditols, using differential scanning calorimetry. The T, and Tg' values of the anhydrous compounds increased in the order pentoses < hexoses < disaccharides. The T, values of the alditols were lower than those of the corresponding sugars. Compounds with high T,/T, ratios had high AH, values and showed rapid crystallisation. The T, and r8' values allowed the prediction of T, as a function of the water content and of the concentration of the maximally freeze-concentrated matrices CC;). The Ci concentration was -80% (w/w) for each carbohydrate. The results can be used to evaluate the physical stability of various carbohydrates at various water contents and in freeze-concentrated solutions.