摘要
中药材在采收后需经过产地初加工处理,其中干燥是产地初加工的必要环节,并直接影响到中药材的品质。传统的自然干燥方式效率低,且药材干燥品质良莠不齐,严重制约中药产业的发展。因此,加强对中药材干燥技术与装备的研究尤为迫切。基于此,该研究综述了中药材干燥技术与装备的研究现状。首先,总结中药材的干燥脱水过程与理化性质变化规律,分析了药材自身特性与干燥条件对水分脱除速率与干燥品质的影响机制。其次,针对热风、热泵、红外、微波、真空与高压电场干燥技术,以干燥机理为基础,总结各类干燥技术的装备结构与工作原理,分析了干燥装备存在的干燥不均匀、能耗大、效率低等问题并探讨了相应改善方法。同时,研究了各类干燥技术在不同工艺条件下的干燥效果,分析了干燥温度、切片厚度、真空度等工艺参数对干燥效果的影响规律,探讨了预处理、阶段式变温变湿、间歇式干燥等赋能干燥效果的工艺手段,并综合干燥品质、干燥效率与干燥成本,得到了各类干燥技术的优缺点与适用范围。进一步地,分析了微波-真空、微波-热风与远红外-热泵三类联合干燥技术不同组合方式下的干燥机理,阐述了各类联合干燥装备的研发进展,探讨了联合干燥技术相较于单一干燥技术的优势以及装备和工艺存在的不足。最后,从提高中药材品质评价标准、完善干燥相关模型、加强干燥装备研发三方面对研究方向进行了展望,以期为中药材干燥技术研究与装备创新研发提供理论依据与技术支持。
The drying process is one of the most essential steps in the initial processing of Chinese medicinal materials.Current natural drying(such as sun and shade drying)approaches have been widely used to improve the quality of medicinal materials,due to their simplicity and low cost.However,the natural environmental conditions can dominate the quality of dried medicinal materials,resulting in low drying efficiency.It is still lacking in the strengthened research of controllable drying.In this study,a critical review was given on the research status of drying technology and equipment for Chinese medicine materials.Firstly,a systematic investigation was performed on the moisture migration,diffusion and removal of Chinese medicinal materials during drying,as well as the changes in color,appearance,microstructure,and physical and chemical properties.The moisture removal rate and drying quality depended mainly on the water content,volume,and tissue structure of Chinese medicinal materials in the conditions of drying,such as temperature,relative humidity and wind speed.Secondly,the drying mechanisms,equipment structure and working principle were performed on various drying,including hot air,heat pump,infrared,microwave,vacuum and high voltage electric field drying.The performances of drying equipment were analyzed,such as uneven drying,high-energy consumption and low efficiency.The structure of the drying chamber was optimized to improve the airflow distribution using heating with multiple heat sources.Chinese medicine materials remained in a dynamic state during drying,in order to improve drying uniformity.At the same time,the drying performances were also evaluated on various drying technologies under different conditions.Some parameters were then considered,including drying temperature,slice thickness,and vacuum degree.The drying temperature generally improved the drying rate while shortening the drying time.Much higher temperature led to reduce the sensory quality and efficacy of medicinal materials.Pretreatment,staged variable temperature and humidity,and intermittent drying were also discussed to obtain comprehensive drying quality,efficiency and cost,and application scopes.Among them,the hot-air drying equipment was suitable for the large-scale drying of cheap Chinese medicinal materials,due to its simple,low cost and large scale,but with the low drying efficiency and quality,as well as the high energy consumption.Vacuum drying was suitable for small batch drying of Chinese medicinal materials,which were easy to oxidize and brown with high added value.The low temperature and oxygen environments were used to improve the drying quality of Chinese medicinal materials,but with the low drying efficiency,the high investment and the operation cost of equipment.Moreover,the drying mechanisms were analyzed for the microwave-vacuum,microwave-hot air,and far infraredheat pump drying in the coupling or series combination modes.The research progress on the development of combined drying equipment was summarized to compare the combined and single drying,in order to explore the limitations of combined drying equipment and processes.Finally,the research directions were predicted from the evaluation standards,the drying-related models,and the drying equipment of Chinese medicinal materials.This finding can provide the theoretical basis and technical support for the research and innovation of drying technology and equipment for Chinese medicinal materials.
作者
王乐意
李长河
刘明政
李康
叶祥瑞
王子文
范林政
王仁坤
赵华洋
坎杂
张国华
邬健康
WANG Leyi;LI Changhe;LIU Mingzheng;LI Kang;YE Xiangrui;WANG Ziwen;FAN Linzheng;WANG Renkun;ZHAO Huayang;KAN Za;ZHANG Guohua;WU Jiankang(School of Mechanical and Automotive Engineering,Qingdao University of Technology,Qingdao 266520,China;School of Engineering,Inner Mongolia Minzu University,Tongliao 028042,China;College of Mechanical and Electrical Engineering,Shihezi University,Shihezi 832003,China;Shandong Wukangxuan Modern Agriculture and Forestry Development Co.,Ltd.,Zoucheng 273500,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2024年第2期1-28,共28页
Transactions of the Chinese Society of Agricultural Engineering
基金
国家自然科学基金项目(52105264)。
关键词
中药材
干燥
机理
装备
效果
工艺
Chinese medicinal materials
drying
mechanism
equipment
effect
process
