Effects Of Different Processing Methods On The Chemical Constituents Of American Ginseng

Objective:This study compared the effects of Natural drying,Steam drying,and vacuum freeze drying methods on the saponins,sugars,and volatile components of American ginseng,and explored the effects of different processing methods on the chemical components of American ginseng,providing a theoretical basis for the processing of American ginseng.Methods:In this study,American gi nseng harvested in the same batch was selected as the research object,and processed in three different ways:Natural drying,Steam drying,and Vacuum freeze drying,and its chemical components were analyzed.1.LC-MS combined with multivariate statistical technique（OPLS-DA）was used to analyze the changes in the saponin components of Panax quinquefolium by different processing methods.2.The content of crude polysaccharide,uronic acid,and reducing sugar in American ginseng under different processing methods was determined using phenol concentrated sulfuric acid method,DNS chromogenic method,and concentrated sulfuric acid m-hydroxybiphenyl method.The monosaccharide composition of different American ginseng products was analyzed using high-performance liquid chromatography.3.The volatile components in different processing methods of American ginseng we re identified by GC-MS.The relative percentage content of each component was calculated b y peak area normalization method,and data were analyzed using multivariate statistical techniques（OPLS-DA,HCA,PCA）.Results:The analysis results of the chemical components in the three different processing methods of American ginseng are as follows.1.Research results of saponins:A total of 51 saponins were identified by LC-MS,including 14 triol type saponins,25 diol type saponins,3 C-17 side chain isomeric saponins,6 oleanolic acid type saponins,and 3 octolone type saponins.Through thermographic analysis of 22 different compound data,the content differences between different processed products were visualized.Compared with Natural drying American ginseng,the contents of ginsenosides Rb₁,Rh₁,Rg₃,Rg₂,Rg₄,Rh₄,F₂,and Rg₅ in Steam drying American ginseng were higher,while the contents of malonyl ginsenosides Rg₁,Re,Rc,Rb₁,Rb₂,Rd,and ginsenoside Rc in Steam drying American ginseng were higher;Co mpared with Vacuum freeze drying American ginseng,the contents of ginsenosides Rb₁,Rh₁,Rg₃,Rg₂,Rg₄,Rh₄,F₂,and Rg₅ in Steam drying American ginseng were higher.The contents of ginsenosides Re,Rc,Rg₁,Rb₃,Ro,Rd,20-（S）-PF₁₁,and 20-（R）-PF₁₁,as well as malonyl ginsenosides Rg₁,Re,Rc,Rb₁,Rb₂,and Rd in Vacuum freeze drying American ginseng were higher than those in Steam drying American ginseng;Compared with Vacuum freeze drying American ginseng,the contents of malonyl ginsenosides Rg₁,Re,Rc,Rb₁,Rb₂,and Rd in Vacuum freeze drying American ginseng were higher than those in Natural drying American ginseng.At the same time,the content of ginsenosides Re,Rc,Rg₁,Rb₃,Ro,Rd,20-（S）-PF₁₁,and 20-（R）-PF₁₁in Natural drying American ginseng is higher.2.Research results of carbohydrate components:there is a negative correlation between the content of polysaccharide and reducing sugar in Vacuum freeze drying and Steam drying American ginseng and the content of uronic acid is the highest in Steam drying American ginseng.The monosaccharides of the three American ginseng products were all composed of arabinose,rhamnose,galacturonic acid,glucose,and galactose,and mannose and fucose were not detected.The content of glucose in each dried product of American ginseng is the highest.There was no significant difference in glucose content among the three groups,and the rhamnose content was basically the same.The arabinose and galactose content in Vacuum freeze drying American ginseng was significantly higher than that in Natural drying and Steam drying American ginseng.The content of galacturonic acid in Steam drying American ginseng was the majority.3.Research results of volatile oil components:a total of 53 volatile components were identified by GC-MS.Except for a few compounds that were not detected,the volatile oil components of the three samples were basically consistent.The volatile oil components are mainly composed of alcohols,fatty acids,esters,and hydrocarbons;The relative percentage content of volatile oil components was 87.12%for Natural drying American ginseng;Stea m drying American ginseng 91.7%;Vacuum freeze drying of 90.5%of American ginseng showed that the detection rate of all samples was greater than 85%,and there were 14compounds with a relative percentage content greater than 1%.A total of 12 differential compounds were screened by multivariate statistical analysis,including panaxynol,palmitic acid,and trans-β-Leucaene is mainly used.The main volatile oil components of Natural drying and Vacuum freeze drying American ginseng are fatty acids and their esters,with a percentage content of about 2.2 times that of Steam drying American ginseng.The main compounds are palmitic acid,linoleic acid,and 10,12-octadecanedienoic acid;Compared with the other two processed products,the content of aldehydes in Vacuum freeze drying American ginseng increased significantly,about 10 times as much as that in Steam drying American ginseng and 3.8 times as much as that in Natural drying American ginseng.The volatile oil components of Steam drying American ginseng are mainly hydrocarbons and alcohols,with a percentage content of about 2 and 1.4 times that of the other two processed products.The higher content compounds are panaxynol,trans-β-Leucaeneβ-Red myrrhene and cypress lignene.