热风微波耦合干燥牛蒡温度梯度研究  

Study on temperature gradient for coupled hot air and microwave drying of burdock

作　　者：宋飞虎[1] 周洪梅[1] 李臻峰[1] 李静[1] 

机构地区：[1]江南大学江苏省食品先进制造装备技术重点实验室,江苏无锡214122

出　　处：《浙江农业学报》2016年第11期1934-1940,共7页Acta Agriculturae Zhejiangensis

基　　金：国家自然科学基金资助项目(51406068)

摘　　要：热风微波耦合干燥是延长牛蒡货架期的有效手段。在热风微波耦合干燥过程中,物料因受到微波与热风的共同作用,表面及中心存在一定的温差,从而产生相应的温度梯度。为了揭示这一温度梯度的影响,通过温控系统分别调节牛蒡表面及中心的温度,形成不同的温度梯度,测定其各自的干燥速率及干后品质。结果显示,干燥速率并不随着温度梯度单调变化。改变温度梯度,当干燥速率最大时,由于干燥过程中样品结构遭到破坏,产品的质量较低。为了进一步改进干燥过程,提出控制策略,在干燥过程中合理改变温度梯度,以兼顾干燥效率及产品质量。Combined microwave-hot air drying is a potential method to extend the shelf life of burdock. During combined microwave-hot air drying,there is a temperature gradient between the hotter center and the colder surface inside the sample. In order to investigate the effect of the temperature gradient,drying processes with fixed core and hot air temperatures were carried out,and the drying rate and quality of dried product were analyzed. It was found that the drying rate did not change monotonously as the temperature gradient increased. When the drying time was the shortest,the product quality was poor due to the high drying rate. To further improve the drying process,temperature gradient control strategy was proposed for drying process. With this strategy,drying efficiency and product quality could be balanced.

关 键 词：热风微波耦合 温度梯度 牛蒡 水蒸气扩散 

分 类 号：TS234.3[轻工技术与工程—粮食、油脂及植物蛋白工程]