我国小麦水分吸着等温线4-参数GAB方程研究

Study on Four-parameter Modified GAB Equation Fitting for EMC/ERH Data of Chinese Wheat Varietie

在水分活度(aw)>0.85条件下,小麦样品易发生霉菌生长而影响平衡水分测定的准确性,本研究采用Blahovec和Yanniotis 2009年发表的适合aw在0～1的修正4-参数GAB方程(MGAB),对测定的我国13个小麦品种的水分吸着等温线数据进行拟合和分类。结果表明,MGAB方程拟合的决定系数(R2)>0.97,平均相对百分率误差(MRE)<8.34%,方程的每个参数在红麦与白麦之间、硬麦与软麦之间、春麦与冬麦之间,差异不显著。但是,同一小麦品种吸附等温线的方程参数,不同于解吸等温线的对应方程参数。另外,根据D10、Rfi、awn指标判断小麦水分吸着等温线类型,13个小麦品种的吸附和解吸等温线均属于接近Langmuir类型的S型等温线。结论是小麦水分吸附与解吸的MGAB方程参数可用于小麦收获后干燥及储藏通风操作。

under the condition of water activity（aw）〉0.85,wheat samples are subject to easy fungal growth,which may affect the precision of equilibrium water determination,In this paper,the four-parameter GAB equation（MGAB） suitable for aw 0-1 and published by Blahovec and Yanniotis in 2009 was used for fitting and classification of the determined sorption isotherms of 13 wheat varieties in our country.The results showed that the coefficient of determination of the MGAB equation fitting（R^2） was〉 0.97,the mean relevant percentage error（MRE） was〈 8.34,each parameter of the equation did not differ obviously between red and white wheat,hard and soft wheat,and spring and winter wheat.However,the equation parameters of the sorption isotherms in the same wheat variety was different from the correspondent equipment parameter of the desorption isotherm.In addition,according to D10,Rfi and awn indices,the moisture sorption isotherm of the wheat was judged that the sorption and desorption isotherms of 13 wheat varieties were close to Langmuir type S isotherm.The result was that the parameters of the wheat moisture sorption and desorption MGAB equation could be used for drying,storage and ventilation of the harvested wheat.