Agriculture and Environment, The University of Sydney, NSW 2006, Australia.
J Agric Food Chem. 2012 Jun 27;60(25):6439-46. doi: 10.1021/jf3011992. Epub 2012 Jun 19.
The phase transitions of pea starch over a wide range of water content were investigated by differential scanning calorimetry (DSC). Swelling of starch granules increased progressively with increasing water content. The main endotherm G broadened progressively with increasing water content up to 94.5 wt % (water:starch ratio 15:1), above which it became too broad to define. The corresponding peak and conclusion temperatures and enthalpy change increased with increasing water content. Scanning electron microscopy (SEM) showed that, at a water:starch ratio of 2:1 (water content of 70.7 wt %), starch granules only swelled partially with discernible granular contours still clearly evident. The results of swelling power tests and SEM images revealed that the endotherm G obtained at a water:starch ratio of 2:1 represented only partial swelling of starch granules. The transition from a narrow to broad endotherm G was interpreted to reflect the thermal transition behavior progressing from limited swelling to maximum swelling and then partial dissolution and leaching of starch polymers from the granules.
采用差示扫描量热法（DSC）研究了豌豆淀粉在较宽含水量范围内的相变。淀粉颗粒的溶胀随含水量的增加而逐渐增加。主要的吸热峰 G 随含水量的增加逐渐变宽，直至达到 94.5wt%（水：淀粉比为 15:1），超过此值后变得太宽而无法定义。相应的峰和结论温度以及焓变随含水量的增加而增加。扫描电子显微镜（SEM）表明，在水：淀粉比为 2:1（含水量为 70.7wt%）时，淀粉颗粒仅部分溶胀，仍可明显看出颗粒轮廓。溶胀力测试和 SEM 图像的结果表明，在水：淀粉比为 2:1 时获得的吸热峰 G 仅代表淀粉颗粒的部分溶胀。从窄到宽的吸热峰 G 的转变被解释为反映了从有限溶胀到最大溶胀，然后淀粉聚合物从颗粒部分溶解和浸出的热转变行为。
