白果微波干燥特性及干燥动力学模型研究

Study on the microwave drying characteristics and drying kinetics model of Ginkgo biloba

利用微波干燥技术,以干基含水率、干基失水速率和感官评分为指标,采用单因素实验确定微波功率和装载量对白果干燥特性的影响。结果表明,微波功率与装载量比值(微波功率密度)越大,白果干燥时间越短,微波功率密度>10 W·g^(-1)或<6 W·g^(-1),白果微波干燥过程分为加速和降速阶段,而微波功率密度在4.71~9.19 W·g^(-1)干燥过程分为加速、恒速和降速阶段;载重量60.0 g,微波功率385 W(微波功率密度6.42 W·g^(-1))时,白果感官综合评分(7分)最佳。运用Matlab软件建立白果的微波干燥的水分比与干燥时间的动力学模型,进行回归拟合检验结果表明,白果干燥过程符合Page模型,模型相关系数为0.999,所得方程能够用于各阶段对干燥速率进行描述。

Using the microwave drying technology, this paper took moisture content, misture ioss rate and sensory score as evalution indexs standard, and made a single factor experiment to define the suitable microwave power and material load witch to affect the drying properties of ginkgo fruit.Resuh showed that the ratio of microwave power to material load（ microwave power density） ,higher microwave power density carried out to shorter drying time.Microwave power density of 〉 10 W·g^-1 or 〈6 W·g^-1, the microwave drying subsection process of ginkgo fruit was contained two stages ： speed- up and speed- down, while microwave power density in the 4.71 ~9.19 W·g^-1, the microwave drying subsection process of ginkgo fruit was contained three stages： speed-up, constant- speed and speed- down. Material load 60.0 g, microwave power 385 W （ microwave power density 6.42 W·g^-1 ）, the best sensory quality score of dried products was 7. A kinetic model of moisture content and action time of microwave drying of ginkgo was established by Matlab based on experimental data and test of fit was carried out for the model. Results showed that model of page could accurately describe the microwave drying process of ginkgo fruit, coefficients of models were above 0.999 and the moisture content and drying rate at each period could be described by the equation obtained.