School of Food Science and Technology, Hunan Agricultural University, 410128 Hunan, China.
State Key Laboratory of Food Science and Technology, Jiangnan University, 214122 Jiangsu, China.
Food Chem. 2014 May 1;150:267-73. doi: 10.1016/j.foodchem.2013.10.122. Epub 2013 Nov 5.
Drying phenomenon of aqueous pullulan solutions at 50°C was investigated by ATR-FTIR spectroscopy and two-dimensional correlation infrared spectroscopy. Two-dimensional asynchronous spectrum at 1800-1500cm(-1) wavenumber was resolved into three separate bands, which were assigned to aggregated water with strong hydrogen bond (AW-S), aggregated water with moderately hydrogen (AW-M) bond, and free water (FW), respectively. Curve fitting results indicated that the quantities of the three species of water were constant during the first 55min of drying process. However, the area of the three bands (at around 1047, 1022 and 998cm(-1)) varied as drying progressed, implying the formation of more-ordered pullulan chains structure, as well as increased pullulan chain-chain interactions. Further analysis using 2D asynchronous correlation spectroscopy in 1200-950cm(-1) wavenumber regions revealed the sequence of spectral changes during the drying process.
在 50°C 下，通过衰减全反射傅里叶变换红外光谱和二维相关红外光谱研究了水性普鲁兰溶液的干燥现象。在 1800-1500cm(-1)波数处的二维异步光谱被分解为三个单独的带，分别分配给具有强氢键的聚集水（AW-S）、具有中等氢键的聚集水（AW-M）和自由水（FW）。曲线拟合结果表明，在干燥过程的前 55 分钟内，三种水的数量是恒定的。然而，随着干燥的进行，三个带（约 1047、1022 和 998cm(-1))的面积发生了变化，这意味着普鲁兰链结构形成了更多的有序结构，以及增加了普鲁兰链-链相互作用。进一步在 1200-950cm(-1)波数区域使用二维异步相关光谱分析表明，在干燥过程中光谱变化的顺序。
