[Objectives]To determine the drying process of different functional rhubarbs.[Methods]The contents of tannins,bianthrone,free anthraquinones and combined anthraquinones in medicinal rhubarb were determined by HPLC.The results were analyzed by two-way analysis of variance.[Results]Under different drying conditions,the contents of tannins,bianthrone,free anthraquinones and combined anthraquinones in medicinal rhubarb were significantly different.Taking the tannins content as the index,the optimum drying condition of the rhizome is 1 cm thick,dried at 60℃,the root is cut 1 cm thick,and dried at 30℃;the bianthrone content is used as an indicator,the rhizome is optimally dried.The condition is to cut 1 cm thick,dry at 60℃,the root is cut to 5 cm thick,and dried at 40℃;the free anthraquinones content is used as an index,and the optimum drying condition of the rhizome is 3 cm thick and dried at 50℃.The root is cut to a thickness of 3 cm and dried at 30℃.The combine anthraquinones content is used as an indicator.The optimum drying conditions for the rhizome are 5 cm thick,dried at 40℃,and the root is cut to 5 cm thick and dried at 70℃.[Conclusions]Different functional components of rhubarb have different directional processing methods.The drying process can reduce the drying temperature or increase the thickness of the slice,and the directional processing of the diarrhea-type rhubarb can be processed.The drying process can be carried out by increasing the drying temperature or reducing the thickness of the slice directed processing of heat-clearing and purging-fire rhubarb.
