干燥温度对SPI/CMC复合膜中硬脂酸结合形态的影响

Effect of Drying Temperature on Stearic Acid State in SPI / CMC Composite Films

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（SPI／CMC／SA）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2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不再显示硬脂酸的典型羰基基团吸收峰（1712cm-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，硬脂酸与其他分子间紧密结合，分子间相互作用力提高。

The effect of drying temperature （30, 60, 90, and 120 ℃） on the state and distribution of stearic acid within soybean protein- isolate/carboxymethyl cellulose/stearic acid （SPI/CMC/SA） composite films has been evaluated in the paper. The stearic acid presented as a free and bound state in the SPI/CMC/SA composite films, amoung which, the bound state of the stearci acid was increased in line with the raising drying temperature. At drying temperature 90 ℃, there was no absorption of 1 712 cm-1 occurred in the FTIR spectra of the composite film, which was the characteristic absorption of the stearic acid. Also there was no weight loss on condition of 210 ～ 280 ℃ in the thermalgravitic profile of the composite film, which was the main degradation of the stearic acid. At drying temoera-ture of 90 ℃, the molecular interaction could be intensified between the stearic acid and the other ingredients.