| In recent years, with the development of Chinese traditional medicine,traditional extraction is not only complicated, wasting energy and time but alsohigh content of impurity. So it can't meet with the demand of the development. Tosolve this problem, the way is only to carry out modernization of Chinesetraditional medicine. The extraction, separation and purification are the key basictechnologies of Chinese traditional medicine modernization and play a veryimportant role in the production of herbs. However extracting technology directlyimpacts on medicinal materials'use and the rear machining, is regarded as aimportant part of modernization of Chinese traditional medicine. The essentialcomponents of herbs can be extracted furthest by advanced extracting technology.The product'science and technology is enhanced, so its competitive power isboosted up in the market. Finally, the good economic and social efficiencies will beachieved.In this thesis, the high pressure extracting technology (HPET) is used toextract the essential components of herbs. Extracting polysaccharides from RadixAstragali act as an example. Study on the whole extracting process indicates thatHPET has many unique characteristics and it shows a vast development prospectand huge potential. Major works and conclusions are as follows:1.Use phenol-vitriol method to measure Astragalus Polysaccharides (APS). Theeffect factors of HPET are analyzed with Radix Astragali in detail. By largenumbers of trial and error, the effect factors of HPET to extract APS are asfollowing: soaking time, pressure, ratio of raw material to solvent and holdingpressure time. Results were discovered as when the soaking time changes between0h and 4h, the extraction rate of APS increases with the prolonging of soakingtime. whereas the soaking time exceeds 4h, with the prolonging of soaking timethe extraction rate changes slightly. With the increase of pressure between 0MPaand 300MPa, the relationship of the extraction rate and pressure is shown in linearequation. While on the contrary the extraction rate decreases slightly between300MPa and 600MPa. The extraction rate increases with the increase of the ratioraw material to solvent that the range is from 1:10 to 1:50.While it is beyond 1:50the extraction rate of APS have no obvious change. Because under the highpressure the diffusion speed is very great, and in a very short time, the solubilityand diffusion in the inner and outer cells got balanced. So for economizing onenergy and time, the appropriate holding pressure time is 2min. At last the rangesof the selected factors is as follows: soaking time is 4h~6h, pressure is200MPa ～400MPa, ratio of raw material to solvent is1:40～1:60. 2. We use uniform design method to optimize the test, and use uniformdesign's software V4.0, that is introduced by the inventor of uniform design, Prof.Fang Kaitai of Hong Kong Baptist University, to analyze the test results. Theoptimum regression equation is shown as follow, that is provided by the uniformdesign software V4.0: Y=11.3066667 + 0.0582833X1 -0.4066667X2 -0.0001151X1 2 -0.0015917X1X2 + 0.0004833X1X3 + 0.0317500X2X3 -0.0022750X3 . The optimum process parameters to extract APS by HPET, 2according "the function of model analysis"provided by softwareV4.0, are asfollow: pressure 350MPa, ratio of raw material to solvent 1:60, soaking time 5h;the forecast range of extraction rate of APS of HPET is 24.21% to 24.35%. Threeparallel tests are made to verify the above optimum conditions and the obtainedresults are good repetition and approaching to the expectation. By matlab designsoftware the relationship between the extraction rate of APS and the effect factorsare plotted and analyzed directly, thus we know that the optimum condition isreliable. 3.The extraction rate and characteristics among HPET, heat-reflux, soakageand ultrasonic technologies are compared and analyzed systematically, whichcomes to the following conclusion. The extraction rate of APS by heat-refluxextraction technology is 23.89%, and this method is not only complicated, wastingenergy and time but also high content of impurity. The extraction rate of APS bysoakage extraction technology is 20.14%. The lower extraction rate, the longerextraction time and lower efficiency are shortcomings of this method. Theextraction rate by ultrasonic extraction technology is 22.56%. The prolonging ofultrasonic time can increase the extraction rate but excessive impurity and greatnoise, which make against the development of industrialization. So it can beapplied only in laboratory. The highest extraction rate is 24.28% by HPET,increasing 2.0% than traditional heat-reflux, 20.6% than soakage, 7.6% than...
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