Effects of moisture content, molecular weight, and crystallinity on the glass transition temperature of inulin

• Published in: Carbohydrate polymers Vol. 83; no. 2; pp. 934 - 939
• Main Authors: Kawai, Kiyoshi, Fukami, Ken, Thanatuksorn, Pariya, Viriyarattanasak, Chotika, Kajiwara, Kazuhito
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.01.2011; Elsevier
• Subjects: Applied sciences; crystal structure; differential scanning calorimetry; equations; Exact sciences and technology; Freeze-concentrated glass-like transition temperature; Fructan; Glass transition temperature; Inulin; molecular weight; Natural polymers; Physicochemistry of polymers; Starch and polysaccharides; Water absorption; water content; Freeze-concentrated glass-like transition temperature; Water absorption; Fructan; Glass transition temperature; Inulin; Structure effect; Oside polymer; Experimental study; Prebiotic; Molecular weight property relation
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2010.09.001

Effects of moisture content, molecular weight (MW), and crystallinity on the glass transition temperature ( T g) and freeze-concentrated glass-like transition temperature ( T ′ g ) of a fructan (inulin) were investigated using differential scanning calorimetry. The T g of inulin samples decreased with increasing moisture content. The T g of semi-crystal inulin was higher than that of amorphous inulin. These results were fitted to the Gordon–Taylor equation, and k values, reflecting the sensitivity to the water plasticizing effect, were obtained. The k value was plotted against anhydrous T g, and the relationship of amorphous inulin was described with a linear function. T g of anhydrous inulin samples and T ′ g of inulin–water mixtures increased with increasing MW, and the results were described empirically by a stretched exponential equation. These results will help to predict T g and T ′ g of inulin, depending on the moisture content, MW, and crystallinity.