糖渍甘薯热风干燥特性及数学模型研究

Hot Air Drying Characteristics and Mathematical Modeling of Sugar Infused Sweet Potato Slices

研究不同糖渍质量分数(10%、15%、20%、30%、40%、50%、70%)浸渍条件下熟化甘薯的热风干燥特性及对有效水分扩散系数(Deff)的影响。比较Newton、Page和Henderson and Pabis 3种模型在糖渍甘薯热风干燥中的适用性,结果表明:Page模型(MR=exp(-ktn),其中,MR为水分比;k、n为模型参数;t为时间)显示最佳的拟合效果,其中Page模型参数k与糖度c成线性关系,指数n与c基本无关,此时模型的判定系数R2为0.982。通过对不同糖度(c)条件下甘薯的(Deff)计算,表明Deff与c呈立方关系,拟合度为0.984。利用Arrhenius关系得到糖渍甘薯片和未糖渍甘薯片的指前因子(D0)和活化能(Ea),结果表明,糖渍甘薯片的D0(6.66×10-8m2/s)和Ea(12.423kJ/mol)均低于未经糖渍预处理的甘薯片的D0(9.69×10-4m2/s)和Ea(40.103kJ/mol)。

After 10 h of infusion in different concentration of sugar solution （10%, 15%, 20%, 30%, 40%, 50% or 70%）, sweet potato slices were subjected to hot air drying and then examined for hot air drying characteristics and effective moisture diffusivity. The drying data were fitted to Newton, Page, and Henderson and Pabisnine models. The results showed that Page model fitted best with R2 value of 0.982. The sugar content c had a linear relationship with the parameter k, but no relationship with the parameter n. The effective moisture diffusivity Deff under various levels of c were calculated and compared. It was found that Deff had a significant cubic relationship with the initial sugar content value c, with R2 value of 0.984. The pre-exponential factor Do and activation energy Ea were calculated based on the Arrbenius relationship. Both Do and Ea value of sugar infused sweet potato slices were larger than those of slices without sugar infusion treatment.