Study Of Extraction And Purification Of Ginseng Effective Components Extracted By Supercritical Fluid Extraction

With five-year cultivated ginseng used as raw material, the effective components in ginsengincluding lipid-soluble components，ginsenosides, polysaccharides and starch were extractedusing supercritical CO2extraction technique. The optimized conditions of supercritical CO2extraction process for ginseng effective components were studied and the corresponding abstractwas purified and identified. The purpose was to realize the modernization of quality control ofginseng effective components extracted by supercritical CO2. The main results of investigationwere as follows:(1) The lipid-soluble components in ginseng were extracted using supercritical CO2extraction technique. The conditions of extraction process were optimized through orthogonaldesign test. The best extract conditions was found to be25MPa of extraction pressure,40℃of extraction temperature,3.5h of extraction time and1:0.6of material to entrainer ratio(g/mL).Under such conditions, the highest extract yield of ginseng lipid-soluble components was（85.38%±3.16%）, which was higher than the one reported in the earlier relative researchliterature. The analysis result of ginseng lipid-soluble components by gas chromatography-massspectrometry (GC-MS) showed that a total of28compounds were identified, which consisted ofsterols, fatty acids, sesquiterpenes, esters and alkene mainly.(2) With the extract residues defatted by supercritical fluid extraction as the raw material,the supercritical fluid CO2extraction assisted by supersonic process was applied to extractginsenosides and the purification was performed by macroporous resin. Determination ofginsenoside Rg1, Re, Rb1, Rc, Rb2and Rd in extracts was performed by high performanceliquid chromatography (HPLC). On the basis of single-factor experiments, the orthogonal testswas performed to study the effect of extraction pressure, extraction temperature, extraction time,the amout of entrainer and the concentration of entrainer on the extract yield of ginsenosides,with ultrasonic time and density of ultrasonic power set at20min and900W/L respectively. Theresults showed that all of the five factors were highly notable factors affecting ginsenosideextract yield. When extraction pressure was35MPa, extraction temperature was45℃,extraction time was2.5h, the ratio of material to entrainer （g/mL）was1：3.0and theconcentration of entrainer was70%, the highest extract yield of ginsenosides, which was（2.2518±0.0553）%, was obtained, and the yields of ginsenoside Rg1, Re, Rb1, Rc, Rb2andRd were(0.3793±0.0156)%,(0.3484±0.0071)%,(0.7448±0.0260)%,(0.2868±0.0137)%,(0.2791 ±0.0056)%,(0.2134±0.0167)%, respectively. Although the yield of ginsenosides bysupercritical fluid CO2extraction assisted by supersonic was a little lower compared with theconventional solvent extraction method, the advantages including simple separation procedure,no solvent contamination and protecting heat-sensitive components were incomparable to otherextraction methods.(3) The extract residue, in which the fat and ginsenosides were removed by supercriticalfluid extraction, was used as the raw material and the supercritical fluid assisted hot waterextraction was applied to extract polysaccharides. On the basis of single-factor experiments, theorthogonal test was used for the optimization process. The optimized extraction conditions wasidentified to be30MPa of extraction pressure,80℃of extraction temperature,1.5h ofextraction time and0.20mm of the material particle size. The extract yield and purity of ginsengpolysaccharides were（41.28±1.63）%and（51.92±2.22）%respectively, which were higherthan those of traditional hot water extraction by15.50%and10.61%respectively, while the timewas only1/4of the traditional hot water extraction. Although the extract yield of ginsengpolysaccharide extracted by supersonic-assisted extraction was slightly higher than thesupercritical fluid assisted hot water extraction, the purity of the obtained ginsengpolysaccharide was notably lower than the supercritical fluid assisted hot water extraction.Result of high performance liquid chromatography (HPLC) determination showed that contentsof glucose, galactose and arabinose in the ginseng polysaccharide extract of the supercriticalfluid assisted hot water extraction was notably higher than both traditional hot water extractionand supersonic-assisted extraction, which indicated that the supercritical fluid assisted hot waterextraction is a fast and efficient new extraction method and it is somewhat of significance in theindustrial manufacture and application of ginseng polysaccharide.(4) The extract residue, in which the fat and ginsenosides had been removed bysupercritical fluid extraction, was used as the raw material and the supersonic-assisted extractionwas applied to extract ginseng starch. The composition，transparency，freeze-thaw stability andretrograded property of ginseng starch were analyzed compared with those of potato starch. Theresults showed that with aspect of starch composition, the amylase content of ginseng starch waslower than potato starch, while the content of amylopectin was higher than potato starch. Withrespect of solubility and swelling capacity, they showed an increasing tendency both in ginsengand potato starch as temperature went up. However, the solubility and swelling capacity ofginseng starch was higher than potato starch on the whole. With respect of transparency andfreeze-thaw stability, the transparency of potato starch was lower than potato starch, whilefreeze-thaw stability of the two kinds of starch were similar. With respect of retrograded property, it gradually increased as time went by both in ginseng and potato starch. But theretrograded property of ginseng starch paste was lower than that of potato starch paste in onepoint. Through the research of physicochemical property in ginseng starch, a theoretical basiswas provided for the further utilization of ginseng starch.