Nutritional Components Analysis And Antioxidant Properties Of Different Varieties Of Jujube (Ziziphus Jujuba Mill.)

Jujube(Ziziphus jujuba Mill.)is an important "medicine and food" plant in my country.It has the effects of nourishing the middle energy and nourishing qi,nourishing the blood and calming the nerves.In this study,37 kinds of jujube fruits were used as raw materials,and their nutritional components and antioxidant activities were studied.Comprehensive evaluations of jujube germplasm resources were made to select high quality jujube with the help of principal component analysis and cluster analysis.Provide a theoretical basis for the future breeding,quality improvement and resource development and utilization of red jujube.Specific research results are as follows:(1)With polyphenols as the detection index,the ultrasonic-assisted extraction method was adopted,and the response surface(RMS)was used to optimize the extraction process of polyphenols.Three independent single factor variables of ethanol volume fraction,material-to-liquid ratio,and ultrasonic power were investigated.The optimal conditions were determined as follows: the material-to-liquid ratio is 1:20(g/m L),the ultrasonic power is 275 W,the ethanol volume fraction is 67%,and the polyphenol extraction amount is 12.253 mg GAE/g DW.(2)Titration,UV spectrophotometer and HPLC were used to determine the total phenols,total flavonoids,Vc,total triterpene acid,c AMP,polysaccharides,six kinds of phenolic acids((+)-catechin,chlorogenic acid,coffee Acid,coumarin,rutin,cinnamic acid),etc.for determination and analysis.16 varieties with high total polyphenols,14 varieties with high total flavonoids,15 varieties with high Vc,and 23 varieties with total triterpene acid were screened out.12 high polysaccharide varieties,12 high c AMP varieties.Among them,the higher content of total polyphenols and total flavonoids are 'Qingxuyuanzao','Meimizao','Suyuanling' and 'Dunhuangdazao';the higher content of polysaccharides and c AMP is' Chaoyangyuanzao','Jianzao','Yutianxiaozao' and 'Jinsixiaozao';the ones with higher Vc and total triterpene acid content are 'Yuanlingyihao','Wudixiaozao','Jinzao' and 'Jinsisanhao'.The higher content of total phenols,total flavonoids,total triterpenes and c AMP are'Yuanling2hao' and 'Tanzao'.(3)In this study,the principal component analysis method was used to comprehensively evaluate the nutritional components of jujubes,and the 12 indicators of the nutritional components of jujube fruits were simplified into four unrelated comprehensive indicators.The cumulative contribution rate reached 75.342%,which reflected most of the information of original quality characters.According to the established comprehensive evaluation model,the top 5 places are 'Qingxuyuanzao','Suyuanling','Xiangzao','Dunhuangdazao' and 'Meimizao'.(4)Cluster analysis was carried out on the main factors in the comprehensive components,and 37 varieties were divided into 5 categories.There was a great difference in the content of nutrients in fruits of different varieties.The first category can be used for the screening of high total polyphenols,total flavonoids,(+)-catechin,chlorogenic acid,caffeic acid and rutin jujube germplasm resources;the second category of jujube fruits can be used for total triterpene acid and c AMP The selection of jujube resources;the third type of jujube fruits can be used for the selection of high-Vc jujube resources;the fourth type can be used for the selection of high-polysaccharide jujube resources.The fifth category can be used to screen high coumarin jujube resources.(5)The fruit extracts of different varieties of red jujube have certain antioxidant capacity,but there are big differences.The DPPH free radical scavenging ability is in the range of9.08?29.79 mg Vc/g DW;the ABTS free radical scavenging ability is in the range of17.50?50.90 mg Trolox /g DW;FRAP reduction ability range is 27.22?62.13 mg Trolox/g DW.'Qingxuyuanzao' has the highest free radical scavenging ability and reducing ability among 37 kinds of red dates.Among them,total phenols,total flavonoids,(+)-catechins,caffeic acid and rutin have a high positive correlation with antioxidant capacity.