以韧性饼干为试验对象，用静态称重法研究了23，30和45 ℃下，饼干的平衡含水率与水分活度的关系，基于常用的等温吸湿模型对试验数据进行拟合。结果表明：韧性饼干的等温吸湿曲线为S型，随着温度的升高平衡含水率会逐渐增加，这与大多数已知食品的吸湿曲线相反；从水分活度适用范围和拟合精度方面来看，GAB模型最适合拟合韧性饼干的等温吸湿曲线。

The relation between equilibrium moisture content and water activity of tough biscuit at 23 ℃, 30 ℃ and 45 ℃ was studied by gravimetric method. The test data were fitted with typical moisture absorption models. The results showed that the moisture isotherm of tough biscuit was S type model; the equilibrium moisture content increases with temperature increases, which was the inversion of other foods; the GAB model is the most suitable for fitting adsorption isotherms of biscuit in the aspects of activity scope and fitting precision.