Physical Aging of Amorphous Fructose |
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| Authors: | V Truong BR Bhandari T Howes B Adhikari |
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| Affiliation: | Authors Truong and Bhandari are with Food Science and Technology, School of Land and Food Sciences, Univ. of Queensland, St. Lucia, QLD 4072, Australia. Authors Howes and Adhikari are with the Dept. of Chemical Engineering, Univ. of Queensland, St. Lucia, QLD 4072, Australia. Direct inquiries to author Bhandari (E-mail: ). |
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| Abstract: | ABSTRACT: Physical aging of amorphous anhydrous fructose at temperature 5 °C and at 22 °C was studied using differential scanning calorimetry (DSC). The dynamic glass transition temperature, Tg0 for unaged samples was 16 °C and 13.3 °C for heating rate of 10 °C/min and 1 °C/min, respectively. The fictive temperature, Tf0 for unaged samples calculated by Richardson and Savill method was 12 °C, which is close to the dynamic value obtained from the lower DSC heating rate. The fictive temperature Tf of the aged fructose glasses at temperatures both below and above the transition region was fitted well by a non-exponential decay function (Williams-Watts form). Aging above the transition region (22 °C) for 18 d increased both the dynamic glass transition temperature Tg and the fictive temperature Tf. However, aging below the transition region (5 °C) for 1 d increased the dynamic glass transition temperature Tg but decreased the fictive temperature Tf. |
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| Keywords: | physical aging fructose glasses glass transition temperature fictive temperature enthalpic recovery |
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