Analysis Of Active Constituents' Content And Its Distribution In Different Mandarin

China is the main source of resources and germplasm center of citrus.The mandarin is the most important cultivar of China and accounting for half of the world's mandarin production.Mandarin is rich in flavonoids,phenolic acids,carotenoids,limonoids,synephrine,etc,which has important physiological functions.It is one of the hot researches at home and abroad.In this study,the composition and distribution of 34 different mandarin varieties including flavonoids,phenolic acids,limonoids,and synephrine were studied systematically,and citrus subgroups were compared and analyzed.The results obtained were compared and analyzed to provide more useful information for the utilization of varieties resources,the quantitative determination of bioactive constituents of mandarin,the development of functional component database,also for the identification,origin traceability and quality control.The main study results were presented as follows:(1)The testing method of synephrine by ultrasonic rapid extraction and high performance liquid chromatography(HPLC)was established.Mandarin were pre-treated by methanol,ultrasonic rapid extracted twice and tested by HPLC-UV.Results showed that the synephrine were separated within 15 min.The average recoveries of pulps and peels,the relative standard deviations,precisions,detection limits(LOD),limit of quantitation(LOQ)of synephrine arranged from 84.7 to 87.2%,80.7 to 89.0%,3.2 to 4.1%,1.7 to 3.1%,1 mg/L(S/N=3),2.5 mg/L(S/N=10),respectively.And the method showed a linear rang of 0.2 to 500 mg/L(r>0.9997).The study of synephrine in 34 mandarin samples showed that peels' synephrine levels were 1.6 to 6.4 times higher than in mandarin pulp.With the highest content in Bendizao peel,the secondary varieties Guangxihongpisuanju and ponkan peel.The content of Citrus hybrid,such as,Buzhihuo,Qingjian and Xugan were the lowest.Synephrine also rich in Guangxihpngpisuanju pulpand poor in Buzhihuo puip.Guangxihongpisuanju,Yindusuanju,Ponkan,Bendizao,Sihuigan are rich in synephrine.In addition,the content sequences of synephrine were shown: oranges> tangerines> miscellaneous tangerines.(2)According to the analyzed results of flavonoids from 34 mandarin samples,flavonoid composition ratios in peel and pulp varied with different citrus varieties.The highest content of flavonoids in the peel is 1.4 to 23.4 times that of the pulp.Flavanones is the major flavonoids in mandarin peel,accounting for 84.96% of the total flavonoid content.Hesperidin is the most major composition,and the secondary compositions were narirutin and didymin.Polymethoxylated flavones is a characteristic flavonoid in citrus,which is rich.The contents and distribution of polymethoxylated flavones is different of varieties and parts.The polymethoxylated flavones content of peel was higer than pulp,and nobiletin was studied the highest,and other less compositions were hesperetin and sinensetin.The nobiletin and hesperetin level in ponkan peel were the highest,and sinensetin is rich in Sihuigan peel.The content of flavonoids in Aiyuan 38 is rich,the content of flavonoids and Narirutin are the highest,and Ponkan is rich in polymethoxylated flavonoids,which can be used as a good resource for flavonoids(3)From the study of 7 phenolic acids in 34 mandarin samples,the phenolic acid distribution of different species was different.Peel portion of the whole fruit was abundant in phenolic acids,and levels of phenolic acids outclass mandarin pulp.Phenolic acids' average content in peel and pulp were 2598.82 mg/kg DW and 770.56 mg/kg DW,respectively.The content of phenolic reached the top in studied Ponkan peel and Guangxihongpisuanju pulp.Hydrocinnamic were the main phenolic acids in the peel and pulp,almost accounting for about 95% of the total phenolic acids,and ferulic acid as the main phenolic acid.Zaoju,Aiyuan and Guangxihongpisuanju that rich in total phenolic acid,ferulic acid,caffeic acid,are mandarin resources with high phenolic acid.Xugan is rich in vanillic acid and is a good source of vanillic acid.(4)According to the analyzed results of 2 limonoids from 34 mandarin samples,limonoids composition ratios in peel and pulp varied with different citrus varieties.The prior compositions were limonoids in mandarin peel,whose levels were 55 to 370.1 times higher than mandarin pulp,the content sequences of diverse limonoids were shown: nomiline > limonin.In Tankan and Bendizao peels,nomiline and limonin reached the top in studied mandarin,respectively.In pulp,the content sequences of diverse limonoids were shown: limonin > nomiline,which is rich in Xugan and Guangxihongpisuanju,respectively.Limonin and nomiline were not detected in Wogan pulp.The content of limonin and nomiline in Zaoju peel was significantly higher than other varieties.(5)The comprehensive analysis found that: the wild species in the rich content of the active substances of Guangxihongpisuanju,Yindusuanju and Mangshanyeju have good development prospects.Xugan is rich in naringin and new hesperidin,which can be used as a good resource for naringin and hesperidin.The bioactive components in the Xugan are different from other varieties,and the relationship between them is far away,which can be used as a reference for the classification of citrus.