魔芋薄层变温热风干燥特性实验研究  

Experimental study on thin layer variable temperature hot air drying of konjac

作　　者：罗传伟[1] 彭桂兰[1] 邱兵涛[1] 吴绍锋[1] 杨玲[1] 

机构地区：[1]西南大学工程技术学院,重庆400715

出　　处：《食品工业科技》2016年第22期137-143,149,共8页Science and Technology of Food Industry

基　　金：国家自然科学基金项目(31301575)

摘　　要：在风速0.75 m/s、厚度5、6及7 mm条件下,对魔芋进行温度50→70℃和70→50℃的薄层变温热风干燥实验,分析了变温温度(50→70℃和70→50℃)及芋片厚度(5、6和7 mm)对魔芋干燥速率的影响,用9个数学模型对魔芋变温实验数据进行拟合,计算魔芋的有效水分扩散系数,并将魔芋薄层变温干燥与恒温干燥进行对比。结果表明:变温条件相同时,魔芋的干燥时间随着芋片厚度的增加而增加;最适合魔芋薄层变温干燥特性的模型是Two-term模型;魔芋的有效水分扩散系数D_(eff)随着芋片厚度的增加而增大;在风速及厚度条件相同时,薄层变温干燥的最大干燥速率比恒温干燥的最大速率更高,且由低温后高温(50→70℃)的变温方式效果更好。This paper discussed the effects of variable temperature （50→70 ℃ and 70→50 ℃）and different thickness of konjac pieces（5,6 and 7 mm）on the drying rate of konjac, nine mathematical models were selected to fit the experimental data,the effective moisture diffusion coefficient of konjac was calculated,and the experiments of thin layer variable temperature drying and constant temperature drying were compared. The thin layer variable temperature drying experiments of konjac were conducted through the air velocities（0.75 m/s）and the thickness of pieces（5,6 and 7 mm）and air temperature（50→70 ℃ and 70→50 ℃）.The results showed that drying time increased with the addition of the thickness of konjac slices while the other drying conditions were same.And the two-term model was much more adequate for describing the thin layer variable temperature drying of konjac.The values of Deff increased with the addition of the thickness of konjac slices. Under the same condition of the air velocities and thickness,the thin layer variable temperature drying rate was higher than the rate of constant temperature drying, and the results showed that the low-to-high mode（50→70 ℃）of variable temperature was better.

关 键 词：魔芋 薄层变温干燥 数学模型 有效水分扩散系数 

分 类 号：TS201.1[轻工技术与工程—食品科学]