Studies On The Quality Evaluation And Optimization Of Suitable Drying Processing Methods Of Angelica Dahuricae Radix

Angelica dahurica is used as foods and herbs in China. The root is recognized as an effective herb medicine to white skin and treat toothache, headache, sinusitis, psoriasis. The coumarins in it have the activities of anti-inflammatory, anti-microbial, anti-tumor, anti-oxidant and so on. The volatile oils have the anti-inflammatory, analgesic activities. The polysaccharides have antiviral, antioxidant activities. They are considered to be the active compounds in Angelica dahurica. The quality of herb medicine would be effected by different areas, breeds, harvest time and processing method. In the present study, the effect of the above-mentioned factors and the suitable drying processing methods for Angelica dahurica were analyzed and discussed.In chapter one, the origin, chemical composition, pharmacological effects, chemical evaluation resources, resource exploit and utilization of Angelica dahurica in recent years were summarized.In chapter two, the main compounds of Angelica dahurica were evaluated.The chapter is divided into four parts.In part one, UPLC-PDA method was adopted to determine the contents of coumarin compounds (bergapten, oxypeucedanin, imperatotin, isoimperatorin). The contents of neutral and acidic polysaccharides were determined by UV-visible spectrophotometry. Hierarchical clustering analysis (HCA) and principal components analysis (PCA) were performed to analyse and evaluate the samples based on the contents of the coumarins and polysaccharides. The results showed that the total coumarins were highest in wild Angelica dahuricae Radix from Tonghua in Jilin province, the contents of neutral polysaccharides, acidic polysaccharides and the total polysaccharides were highest in Angelica dahuricae Radix from Anguo in Hebei province. HCA and PCA showed that the diversity of wild Angelica dahuricae Radix was most obvious to the other cultivars of Angelica dahuricae Radix. There is no significant difference between the root of Angelica dahurica and Angelica dahurica. var. formosana in coumarins and polysaccharides compounds.In part two, the content of byakangelicin, bergapten, oxypeucedanin, imperatorin and isoimperatorin were determined by UPLC-PAD. The contents of neutral and acidic polysaccharides were determined by UV-visible spectrophotometry. The results showed that the content of total coumarins in March and July were higher than other months and the contents of total polysaccharide presented three peak periods in February, April and July, respectively. Correlation analysis results showed that the correlation among coumarins was well, but there is no correlation between coumarin and polysaccharide component or between neutral polysaccharide and acidic polysaccharide. The best time to harvest was in July and it was consistent with the traditional harvest time.In part three, the polysaccharide component in stems and leaves were determined by the methods of phenol-sulfuric acid and carbazole-sulfuric acid. The total contents of polysaccharides in stems were higher in June, and the total contents of polysaccharides in leaves were higher in July. Two unknown compounds were identificated, one was byakangelicol, the other was phellopterin. Lots of stems and leaves were wasted in the traditional harvest time of July. Therefore, the results of the experiment would provide reference for utilization of the aerial parts.In chapter two, the suitable drying processing methods for Angelica dahurica were studied. The chapter is divided into two parts.In part one, the drying kinetics of hot air drying, shortwave infrared radiation drying, natural drying in the shade and natural drying in the sun were studied. With the drying temperature rising, the drying time became shorter and the drying efficiency became higher. The drying time of shortwave infrared radiation drying was shorter than the hot air drying, which may be related to its special heating mechanism. The results showed that the Weibull distribution function was good in simulating the drying process of Angelica dahurica.In part two, HPLC-PDA method was adopted to determine the contents of coumarin compounds. GC-MS with internal standard method was used to determine the content of volatile oil. The appearance of samples was evaluated by the method of composite scores. The results of coumarins contents showed that the natural drying in the sun is higher than natural drying in the shade, variable-temperature drying is the best, and the temperature of constant temperature drying is inversely proportional to the contents of coumarins. The results of volatile oils contents showed that variable-temperature drying was the best, and the temperature of constant temperature drying was inversely proportional to the contents of volatile oils. The results of composite scores showed that hot air drying in 50℃ was the best, followed by natural drying in the sun, natural drying in the shade and shortwave infrared radiation drying in 50℃. Therefore, considering the drying time, the appearance, and the content of active compounds, the hot air machine with temperature and humidity controlled was recommend. The suitable parameters for the machine were that the drying temperature was 50℃, the humidity was 35%.