干燥温度对大豆分离蛋白/羧甲基纤维素膜中硬脂酸结合形态的影响

研究干燥温度（30、60、90和120 ℃）对大豆分离蛋白/羧甲基纤维素/硬脂酸复合膜中硬脂酸分布和结合形态的影响。结果显示硬脂酸以结合态和自由态两种形态存在于复合膜中，随着干燥温度提高，复合膜中结合态硬脂酸的比例提高。当干燥温度为90 ℃时，复合膜的红外光谱图中不再显示硬脂酸的典型羰基基团吸收峰（1712 cm-1）；复合膜的热失重图谱中不再显示硬脂酸的主要热降解现象（210~280 ℃）。因此在干燥温度为90 ℃时，硬脂酸与其它分子间紧密结合，分子间相互作用力提高。

Effect of drying temperature on stearic acid state in soybean protein-isolate/carboxymethylcellulose films

The effect of drying temperature (30, 60, 90, and 120 oC)on the state and distribution of the stearic acid in the soybean protein-isolate/carboxymethyl cellulose/stearic acid (SPI/CMC/SA) composite films was evaluated. The stearic acid presented as the free state and bound state in the SPI/CMC/SA composite films. The bound state of the stearci acid was increased when the drying temperature was raised. When the drying temperature was 90 oC, the absorption of 1712 cm-1 did not show in the FTIR spectra of the composite film, which was the characteristic absorption of the stearic acid. The weight loss did not show in the range of 210~280 oC in the thermalgravitic profile of the composite film, which was the main degradation of the stearic acid. Hence, the drying temperature of 90 oC intensified the molecular interaction between the stearic acid and the other ingredients.