Studies On Quality Standard And Drying Method Of Rheum Palmatum L.

Rheum palmatum L.is a perennial herb of the genus Rhubarb,with various effects such as diarrhea,heat and diarrhea,cooling blood and detoxification,phlegm and blood stasis,and dampness and yellowing.Through the determination and analysis of the main factors affecting the grades of Rheum palmatum L.seeds,seedlings and medicinal products,the corresponding quality grading standards are formulated.By comparing the effects of traditional drying,sun-drying,shade-drying,drying,freeze-drying and other different drying methods on the quality of Rheum palmatum L.,to explore the best drying method of rhubarb,aiming at the standardized production and market circulation of Rheum palmatum L.seedlings And Rheum palmatum L.quality monitoring provides a scientific basis.1.Based on the quality index determination and K means cluster analysis of 90 leaves of Rheum palmatum L.from different sources in Gansu Province,based on the grading standards of quality indicators such as 1000-grain weight,germination rate,water content,clarity,viability and purity.The Rheum palmatum L.seeds are divided into three grades.Namely: first-class seed germination rate ?82.0%,1000-grain weight ?9.50 g,clarity ?97.0%;secondary seed germination rate ?76.0%,1000-grain weight ?9.10 g,clarity ?90.0%;thirdclass seed germination rate ?64.0%,1000-grain weight ?8.70 g,clarity ?86.0%;water content ?10%;seed viability ?80.0%;purity ?99.0%,Among them,primary and secondary seeds accounted for 45.6 percent of the total number of seeds,and unqualified seeds accounted for 21.1 percent of the total number of seeds.2.The quality index and K means cluster analysis of 80 Rheum palmatum L.seedlings collected in various producing areas of Gansu Province were based on four main indicators: root thickness,root length,weight per plant and OD485 nm.Combine the situation of the lateral roots and the results of the health check and the actual production situation.The Rheum palmatum L.seedlings of Gansu Province are divided into three grades,namely: the first plant has a plant weight of ?31.0 g,the root thickness is ?2.1 cm,the root length is ?28.0 cm,and there is no lateral root with a base diameter greater than 3 mm;The seedling weight is ?25.0 g,the root thickness is ?1.8 cm,the root length is ?24.0 cm,and there is no lateral root with a diameter greater than 4 mm;the third plant has a plant weight of ?19.0 g,root thickness ?1.5 cm,root length ?20.0 cm There are a few side roots;seedling vigor OD485 nm ?0.700.Among them,the first and second seedlings accounted for 28.7% of the total number of seedlings;the unqualified seedlings accounted for 28.8% of the total number of seedlings.3.Evaluation of Rheum palmatum L.Specifications by Weight,Shape,Color,Texture and Content Index,The Rheum palmatum L.medicinal materials were divided into four commodity specifications,and the four grades were common: dry goods.Cylindrical,conical,oval or irregular.The appearance of the outer skin is yellowish brown to reddish brown.Solid,some center is slightly soft,the section is reddish brown or yellowish brown,showing graininess;the rhizome of the rhizome is broad,with a star point ring or scattered;the root is developed,with radial texture,forming a layer ring,no star point.The fragrance of the air.No insects and mildew.The heart does not exceed 15%.The moisture shall not exceed 15.0%,the total ash shall not exceed 10.0%,the leachate shall not be less than 25.0%,the total anthraquinone content shall not be less than 1.50%,and the free anthraquinone content shall not be less than 0.20%;the difference point: first-class product,per kilogram 6 or less;second-class products,less than 7 to 10 per kilogram;third-class products,less than 10 to 20 per kilogram;unified goods,Regardless of size.Different specifications of Rheum palmatum L.quality inspection indicators determination results of leachate content general goods> second-class products> first-class products> third-class products,total anthraquinone content second-class products>first-class products>third-class products,unified goods,free anthraquinone content first-class products >general goods>second-class products> third-class products,all quality inspection indicators are in line with the Pharmacopoeia standards,the comprehensive analysis of each index,the quality of Rheum palmatum L.is the best for the first-class products,followed by second-class products,followed by general goods,third-class products are the worst.4.Drying Rheum palmatum L.by comparing traditional methods such as fumigated with sulfur-drying,sun-drying,shade-drying,drying(different temperature,different methods),freeze-drying(-50°C~-60°C),drying time and drying rate of Rheum palmatum L.The comprehensive influence of the inspection items(moisture,total ash),leachate and anthraquinone content showed that the Rheum palmatum L.was dried with the highest content of traditional fumigated with sulfur-drying method,and the dried Rheum palmatum L.had the best scent,texture and color.However,although the traditional method of drying and drying is time-consuming and destructive to tree vegetation and environment,Rheum palmatum L.has not yet found a drying method with little environmental damage,short drying time and minimal damage to active ingredients.Therefore,the most suitable drying method for Rheum palmatum L.is still the traditional method of drying.