摘要
The heating area of the material is large and the thermal efficiency is high,but it is n ecessary to control the suitable drying temperature ofdiffere nt medici nal materials to preserve the effective in gredients.D iff ere nt kinds of Chinese medicine need different drying conditions to fulfill good drying requirements.Natural drying in the shade is one of the traditional drying methods,which takes a long time and is easily affected by the weather.The water volatilizes slowly.It is prone to mildew and discoloration during the drying process.However,it can better preserve the volatile oil components of Chinese medicine.The hot-air drying machine has lower requirements.The medicinal materials have a large heating area and high thermal efficiency,but it is necessary to control the appropriate drying temperature of different medicinal materials in order to preserve the active ingredients of the medicinal materials;it is not suitable for medicinal materials that stick and bind easily.The microwave drying method possesses superiority in drying some valuable medicinal materials such as Ren she n(Radix et Rhizoma Ginseng)and Lurong(Co「nu Cervi Pantotrichum),and the effective ingredients are preserved at a high degree;it can also achieve the purpose of killing enzymes and protecting glycosides and have a good bactericidal effect,but it is not suitable for Chinese medicines containing heat-sensitive ingredients,because it will destroy most of the proteins,amino acids,and peptides of Chinese medicine and result in the loss of efficacy.The far-infrared drying method is suitable for drying thin-layer medicinal materials and is friendly to the environment.Freeze-drying can preserve the active ingredients very well and greatly retain the efficacy,but it has obvious limitations in preserving some Chinese medicinal materials that need to kill enzymes and protect glycosides;besides,the cost is relatively high and the drying time is long.
鲜药材的加热面积大,需要的热效率高,要控制不同药材的适宜干燥温度保存有效成分。不同种类中药干燥需要不同干燥条件才能达到良好的干燥要求。自然阴干作为传统干燥方法之一,时间较长,易受天气影响,水分挥发较慢,干燥过程中易出现霉变、变色等,但可较好保存中药挥发油成分;热风干燥机器要求较低,物料受热面积较大,热效率较高,但需要掌控不同药材的适宜干燥温度,以便保存有效成分,不适于易粘连结块的药材;微波干燥法对一些贵重药材如人参、鹿茸等有良好的干燥优越性,有效成分保存程度很高,还可以达到杀酶保苷的目的,并且有较好杀菌效果,但对于含有热敏性成分的中药并不适用,会破坏中药大部分蛋白质、氨基酸和多肽等成分,造成中药失效;远红外干燥法适用于薄层药材干燥,药材质量较稳定,对环境较友好;冷冻干燥较好保存活性成分,极大保留药效,但应用于一些需要杀酶保苷延长保存时间的中药材明显存在局限性,且运行成本较高,干燥时间较长。
