食品科学 ›› 2020, Vol. 41 ›› Issue (10): 230-237.doi: 10.7506/spkx1002-6630-20190515-156

• 工艺技术 • 上一篇    下一篇

基于“热失控”规律的香菇微波干燥工艺优化

张志勇,李元强,刘成海,燕子豪,朱勇,张友朋,赵月明,郑先哲   

  1. (东北农业大学工程学院,黑龙江 哈尔滨 150030)
  • 出版日期:2020-05-25 发布日期:2020-05-15
  • 基金资助:
    国家自然科学基金面上项目(31571848);哈尔滨市科技项目(2017RAXXJ028)

Optimization of Microwave Drying of Shiitake Mushrooms Considering Thermal Runaway

ZHANG Zhiyong, LI Yuanqiang, LIU Chenghai, YAN Zihao, ZHU Yong, ZHANG Youpeng, ZHAO Yueming, ZHENG Xianzhe   

  1. (College of Engineering, Northeast Agricultural University, Harbin 150030, China)
  • Online:2020-05-25 Published:2020-05-15

摘要: 为解决微波干燥香菇出现的干燥效率和品质的问题,采用数值模拟和台架实验相结合的方法,以微波强度为实验因素,研究不同微波强度下香菇内部微波能吸收规律,探究香菇微波干燥过程中温度和水分变化特性。结果表明:香菇微波干燥升温特征可分为升温、恒温、再升温3 个阶段,分别与微波干燥速率的升速、恒速、降速3 个阶段对应;干燥后期温度升高到80~100 ℃之间出现“热失控”现象,香菇温度急剧上升;香菇干燥过程中心位置出现“热点”,内部微波体积热明显高于外表面。以不超过香菇微波干燥“热失控”温度为参考,提出分段变功率香菇微波干燥方案,前期微波强度为2.4 W/g,后期微波强度为0.8 W/g,缓苏5 min,干燥均匀性最高且干燥效率最佳。研究结果可指导解决香菇微波干燥存在的问题,为香菇微波干燥生产工艺优化提供理论依据。

关键词: 香菇, 微波干燥, 热失控, 仿真, 工艺优化

Abstract: In order to improve the drying efficiency and the quality of shiitake mushrooms under microwave drying, numerical simulation and bench test were used to study the absorption pattern of microwave energy in shiitake mushrooms at different microwave intensities and to investigate the variation characteristics of temperature and moisture during the drying process. The results showed that the characteristics of microwave drying temperature involved three stages: rising, remaining constant, and rising once again. The same trend was observed for the drying rate. As the temperature rose to 80–100 ℃ at the late stage of drying, the thermal runaway phenomenon appeared, and the internal temperature of shiitake mushrooms rose sharply. Hot spots appeared at the center of shiitake mushrooms during the drying process, and the internal microwave volume heat was significantly higher than that on the surface. In order not to exceed the temperature for thermal runaway, microwave drying should be carried out at microwave intensity of 2.4 W/g first and then 0.8 W/g with a 5 min interval, giving the highest drying uniformity and drying efficiency. The research results provide valuable guidance for the microwave drying of shiitake mushrooms.

Key words: shiitake mushrooms, microwave drying, thermal runaway, simulation, process optimization

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