摘要
采用单因素试验法,研究升华干燥系数同预冻方式、预冻终温、加热温度、物料厚度、干燥室压强之间的关系。以游离水升华完全为前提,在慢速预冻、预冻终温-30℃、加热温度80℃的条件下,分别测定不同厚度和压强时物料的升华干燥系数,试验结果用软件Origin 9.0非线性曲面拟合得出升华干燥系数模型,并用VB语言建立升华干燥系数查询数据库,以拓展已建立的关于干切牛肉冷冻干燥高速率升华过程中制品含水率、物料中心温度和升华所需物料表面温度的动态预测模型的适用性。验证实验表明：拓展后的预测模型物料中心温度预测值和实测值绝对误差〈5℃,含水率预测值和实测值相对误差在10%以内,预测模型拓展后可用于预测干燥室压强20~120Pa,物料厚度6~30mm的干切牛肉在冷冻升华干燥过程中物料的中心温度和含水率。
The relationship are discussed,between the sublimation drying coefficient and the mode of pre freezing,pre-freezing temperature,material thickness,heating temperature,pressure of drying chamber.Tests were performed using single factor test method.The sublimation drying coefficient of materials was measured with different thickness and pressure under heating temperature 80 ℃,using slow pre-freezing method in the temperature-30 ℃ on the premise that free water sublimation entirely.The results were fitting by software Origin 9.0and established sublimation drying coefficient query database using VB language.Therefore,the sublimation drying coefficient database of cooked beef slice was set up on the heating temperature 80℃and extended the drying dynamic prediction model of sublimation.The results of verification tests showed that the absolute error of material center temperature between predicted value and measured value less than 5 ℃;The relative error of moisture ratio between predicted value and measured value within 10%.The expanded prediction model could be used to predict the material center temperature and moisture content during drying freeze-dried cooked beef slice within chamber pressure 20~120Pa and material thickness6~30mm.
出处
《食品与机械》
CSCD
北大核心
2016年第2期11-15,90,共6页
Food and Machinery
基金
国家自然科学基金地区基金项目(编号:31160328)
关键词
干切牛肉
冷冻干燥
升华干燥系数
预测模型
cooked beef slice
freezing drying
sublimation drying coefficient
forecasting model
