摘要
在4种温度(10、20、30、40℃)和相对湿度11%~87%的条件下,采用静态平衡称量法测定高、中、低筋小麦粉的吸附与解吸平衡水分,并绘制吸湿等温线,拟合Logistic模型建立吸湿等温线的经验公式。结果表明:在特定温度条件下,高、中、低筋小麦粉的吸湿等温线基本重合,吸湿等温线为"S"型;以中筋小麦粉为实验对象时,得出了以下结论:在等温线图中,10、20、30℃吸湿等温线依次向右下方移动,40℃吸湿等温线与30℃的基本重合;在10、20、30℃条件下,存在吸附滞后现象,温度越低,滞后环越明显。在40℃条件下,未出现滞后现象。建立的吸湿等温线经验公式是有效的。
High-gluten, middle-gluten and low-gluten wheat flours were determined by static equilibrium gravimetric method for adsorption and desorption equilibrium moisture contents under different conditions of temperature (10, 20, 30 ℃ and 40 ℃) and humidity (11%-87%). Based on the obtained data, moisture adsorption isotherms were plotted and a logistic model was fitted to establish an empirical formula. Substantially the same moisture adsorption isotherms of high- gluten, middle-gluten and low-gluten wheat flours were observed as an ‘S'-shaped pattern under specific conditions. The adsorption isotherms of middle-gluten wheat four at 10, 20 ℃and 30 ℃ displayed a shift towards the bottom right of the coordinate. Middle-gluten wheat four revealed basically the same adsorption isotherm at 40 ℃ and 30 ℃. Adsorption hysteresis was observed at 10, 20 ℃ and 30 ℃ and the lower the temperature, the larger the hysteretic loop area. In contrast, hysteretic loop disappeared at 40 ℃. Therefore, a valid empirical formula of moisture adsorption isotherm for wheat flour has been developed in this study.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2012年第19期45-51,共7页
Food Science
基金
"十一五"国家科技支撑计划项目(2006BAD08B04)
江苏省教育厅重点自然科学基金项目(06KJA55017)
江苏省科技厅自然科学基金项目(BK2007183)
关键词
小麦粉
吸附
解吸
吸湿等温线
wheat flour
adsorption
desorpfion
moisture adsorption isotherm