Characterization And Variety Difference Of Non-starch Polysaccharides From Chenopodium Quinoa Willd

The genetic polymorphism and nutritional value of Quinoanon-starch polysaccharides（NSP）from quinoa germplasm resources have been widely concerned,but the chemical composition diversity of NSP from quinoa was seldom reported.The modern pharmacological evaluation has confirmed that quinoa NSP has various biological activities,including antioxidant,inhibition of food digestion,bile acid-binding and cholesterol-lowering,anti-cancer,gastrointestinal protection and immune regulation.The systematic analysis and evaluation of NSP in quinoa germplasm resources have not been reported.In this study,25 NSP samples were obtained from different varieties and different preparation methods as the research object.Based on modern instrumental analysis methods,the physicochemical characteristics of NSP were characterized,and the physicochemical polymorphisms of NSP in quinoa germplasm resources were analyzed and compared.The results can be used as a reference for quality identification and breed selection of quinoa.The main research contents and results are as follows:（1）To establish a preparation method of quinoa non-starch polysaccharides（NSP）.Based on the process of the"enzyme-ultrasound-assisted-water-ultrasound-assisted-enzymatic method",the preparation process was optimized by response surface methodology（RSM）on the basis of single-factor experiments and the temperature solid-liquid ratio and time in the heating and extraction stage were selected as the influencing factors.The optimal extraction conditions of quinoa NSP were as follows:temperature 84℃,solid-liquid ratio 1:36,extraction time 50min.Under these conditions,the predicted yield of NSP was 152.48mg/g,and the actual verified value was 151.67±1.39mg/g.The actual verification test condition is that the extraction value is close to the theoretically predicted value,indicating an excellent fitting degree between the regression equation’s predicted value and the experimental value,and the established extraction process is feasible.（2）Structural characterization of non-starch polysaccharides（NSP）from quinoa.Various solvents and treatment methods prepared by quinoa NSP.The physicochemical properties of NSP were characterized by UV,HPLC,HPSEC-RI,FTIR and scanning electron microscopy.Congo red test results show that quinoa NSP has no triple helix structure,by using HPSEC-RI analysis found that the relative molecular mass of the NSP size differences apparent,PMP before column derivatization analysis quinoa NSP for polysaccharide mixed,its monosaccharide composition mainly:mannose,Rhamnose,galacturonic acid,glucose,galactose,arabinose and trace of glucuronic acid.FTIR infrared spectrum analysis showed that quinoa NSP had the typical characteristic absorption peaks of polysaccharides.The absorption peaks at 1640cm^-1 and 1742cm^-1 indicated that the NSP contained pectin compounds.The absorption peaks at 842cm^-1 and 895cm^-1 indicated that the NSP hadα-type andβ-type glycosidic bonds.（3）Chemical difference analysis of NSP of various quinoa germplasm resources.Based on the established HPLC,FTIR and HPSEC-RI analysis methods of NSP,the NSP prepared by different extraction methods of five quinoa germplasm resources were compared and analyzed.By comparing the extraction rate of NSP,it was found that the content of NSP was more in QHXL,H1 and BL,and the similarity result of monosaccharide composition by HPLC analysis.However,the similarity of FTIR and HPSEC-RI was lower,which could be used as the basis for the identification of NSP polysaccharides in quinoa.NSP of different quinoa varieties prepared by different methods showed significant differences in physical and chemical properties,which could be used as the basis for quality identification and breeding.