青豆种子玻璃化转变温度的研究

Study on Glass-transition Temperature of Green Soybean Seeds

种子在干燥过程会发生玻璃化转变的现象。为了确定含水率和升温速率对青豆种子玻璃化转变温度Tg的影响规律,采用差式扫描量热法(DSC)测试了在含水率11%～27%(d.b.)、升温速率1～5℃/min的青豆种子玻璃化转变温度,并通过外推法确定了数学模型。结果表明:含水率和升温速率对Tg的影响效果明显,Tg值随含水率的增加而降低,随升温速率的增加而增加。测试结果为利用玻璃化转变理论确定青豆种子的最优干燥工艺提供了关键参数。

Glass transition phenomenon could be occurred in the seeds drying process. In order to indentify the influence of the moisture content and heating rate on green soybean seeds glass transition temperature, the glass transition temperature was test with differential scanning calorimetry at moisture content in a range of 11% to 27 % （ d. b） and heating rate from 1 to 5 ℃/min. By using trend extrapolation, glass transition temperature model was gotten. Results indicated that glass transition temperature was decreased with moisture content increased and increased with heating rated increased. The test results provide key parameters for green soybean seeds on optimal drying technology with glass transition theory.