Effect Of Different Processing Methods On Quality Of Gentiana Straminea Maxim.

Gentiana straminea Maxim.is a perennial herb of Gentiana（Tourn.）L.in Gentianaceae.It is one of the basic source plants of Gentiana straminea according to The Chinese Pharmacopoeia（2020 Edition）.It is also a traditional Chinese and Tibetan medicine with roots as medicine.Tibetan medicine is called “Jiejigabao”.The effective components are mainly iridoid glycosides,which have unstable structure and are easily affected by the processing of origin.At present,the processing of Gentiana straminea Maxim.is mainly based on empirical operation and lacks scientific guidance,which seriously affects the quality of medicinal materials.In this study,the gradient experiments of different drying methods,different drying temperatures,different reed lengths and “sweating”drying were carried out.The contents of five iridoid glycosides in Gentiana straminea Maxim.were determined by high performance liquid chromatography（HPLC）.Combined with the appearance color,drying rate and drying time of Gentiana straminea Maxim.the best processing method of Gentiana straminea Maxim.was explored.The main results were obtained as follows:1.Six different drying methods including natural sun drying,natural shade drying,shade drying after killing green,drying at 100 ℃,microwave drying and freeze drying were used to dry Gentiana straminea Maxim..The results showed that different drying methods had important effects on the quality of it.The effective components content of Gentiana straminea Maxim.was significantly higher than that of 100 ℃ drying,natural sun drying and natural shade drying after killing green drying,microwave drying and freeze drying.Combined with the factors of time-consuming,energy consumption and equipment requirements in the actual production process of medicinal materials,it is suggested that the drying method after killing green should be preferred.2.Drying unsliced and sliced Gentiana straminea Maxim.（2 cm in thickness）at 25,50,75,100,125,150,175,200 °C.The results showed that 100 °C was the most favorable temperature for the retention of active ingredients,and its content was significantly higher than other drying temperatures.And at the same drying temperature,sliced Gentiana straminea Maxim.effective components content is higher.Considering the drying rate,appearance color,drying time and other factors,it is recommended to dry the slices at 100 °C.3.Determination of “sweating”,different “sweating” stack height and different“sweating” time treatment of Gentiana straminea Maxim.five effective components content.The results showed that the content of effective components in medicinal materials with 75 cm height of “sweating” stack was significantly higher than those in medicinal materials without “sweating” direct drying and other medicinal materials with “sweating” stack.It was suggested that the height of “sweating” stack should not be less than 75 cm in the processing of “sweating” of Gentiana straminea Maxim.The effective component content of “sweating” 72 h was significantly higher than that of other “sweating” time samples.It is suggested that the best“sweating” time of Gentiana straminea Maxim.is 72 h.4.The length of Gentiana straminea Maxim.was cut to 0 cm,0.5 cm,1 cm and1.5 cm,and the content was determined by slow drying（natural drying）and rapid drying（100 °C drying）.The results showed that the effective component content of Gentiana straminea Maxim.with the length of 1 cm was significantly higher than that of Gentiana straminea Maxim.with the length of 0 cm,0.5 cm and 1.5 cm.Therefore,it is suggested that the length of Gentiana straminea Maxim.should be kept at 1 cm during the processing of Gentiana straminea Maxim.