香菇热风微波流态化的干燥特性与机理分析  

Studies on Characteristics and Mechanism of Hot Air-Microwave Fluidized Drying of Lentinusedodes

作　　者：李冰[1] 尹青[2] 殷丽君[1] 张凯华[1] 陈浩[1] 韩清华[2] 

机构地区：[1]中国农业大学食品科学与营养工程学院,北京100083 [2]中国农业机械化科学研究院,北京100083

出　　处：《中国食品学报》2015年第5期134-139,共6页Journal of Chinese Institute Of Food Science and Technology

基　　金：国家'863'高技术研究发展计划项目(2011AA100802);科研院所技术开发研究专项(2012EG119149);国家自然科学基金项目(31171692)

摘　　要：通过香菇热风微波流态化的干燥特性试验,探讨微波功率、热风功率和振动频率对香菇干燥速率的影响规律;应用低场核磁共振技术(NMR)分析香菇热风微波流态化的水分迁移变化。试验结果表明,热风微波流态化干燥香菇过程按降水速率大小分为预热、恒速和降速3个阶段。干燥速率随微波功率及热风功率的增大而明显加快,振动频率对干燥速率的影响较小。核磁共振结果显示:干燥预热阶段主要脱去自由水,恒速阶段主要是不易流动水与结合水之间的转化并脱去大量自由水,降速阶段是脱去结合水。在香菇热风微波流态化干燥过程中,提高水的流动性并延长恒速阶段干燥时间有利于提高干燥速率。Hot air-microwave fluidized drying is a new technology to produce high quality dried Lentinusedodes. The influence rules of microware power, hot air power and vibration frequency of the expansion ratio were determined. The water migration and variation in Lentinusedodes drying were analyzed by NMR. The results indicated that the drying pro- cess was divided into three stages as follows： pre-heating phase, constant-speed phase and decelerated phase. During the drying process, the dehydrating rate increased with the increase of microwave power and hot air power. The vibration frequency had less effect on dehydrating rate and drying time. NMR results showed that the free water decreased signifi- cantly in the pre-heating phase. During the constant-speed phase, moisture content was stable and the extra-cellular wa- ter had transformed to bound water. The bound water was took off significantly in the decelerated phase. Conclusions showed that improved the liquidity of water and extended the constant-speed phase drying time were conducive to im- prove the drying rate.

关 键 词：微波流态化 热风干燥 水分 香菇 核磁共振 

分 类 号：TS219[轻工技术与工程—粮食、油脂及植物蛋白工程]