Study On The Change Of Nutrition And Functional Components In Nanfeng Tangerine During Ripening

Nanfeng tangerine is a unique citrus growing in Jiangxi province and has a good taste.Nanfeng Tangerine is popular with amino acids,selenium vitamins,trace elements and bioactive substances such as flavonoids,limonoids and phenolic acids.there are few study on the nutrient composition and active ingredients of Nanfeng tangerine.The dynamic processes of nutritional and functional ingredients during ripenss are not reported.To provide a theoretical basis for the comprehensive process of Nanfeng tangerine,this paper is focus on the dynamic changes of nutrients(e.g.total acid,total sugar,soluble solids)and functional components(e.g.total phenol,total flavonoids,antioxidant activity),The main findings are as follows:(1)Established high performance liquid chromatography(HPLC)detection methods for major organic acids,flavonoids,phenolic acids and limonoids in Nanfeng tangerine fruits.Each method has low detection limit,high precision and accuracy,as well as high recovery rate;it is suitable for the detection of the above nutrients in Nanfeng tangerine fruit samples of different maturity periods.(2)The basic physical and chemical properties and nutrient composition of Nanfeng tangerine fruit during ripening were discussed.The Pearson correlation between total phenolics,total flavonoids,total limonin and antioxidant activity was analyzed.The results showed that the total acid decreased gradually,the total sugar and soluble solids content increased gradually,and the ratio of solid acid to sugar and acid to acid increased with the prolongation of harvesting period.Nanfeng tangerine is rich in functional nutrients such as total phenols and total flavonoids,and its content in the peel is much higher than that of pulp.Therefore,Nanfeng tangerine peel is suitable for deep processing and utilization;the total phenolic content and total flavonoid content of Nanfeng tangerine peel and pulp are significantly correlated with antioxidant activity(Pearson coefficient is greater than0.8),while the correlation between limonin content and antioxidant activity is not significant(the Pearson coefficient was less than 0.644).(3)Nanfeng tangerine contains citric acid,ascorbic acid,succinic acid,fumaric acid,etc.Citric acid is the main organic acid.The content of organic acids showed a downward trend during the ripening process.The main flavonoids in Nanfeng tangerine are hesperidin,which is rich in flavonoids.Hesperidin is the main flavonoid.In addition to hesperidin,it also contains methoxyflavone(e.g.Tangeretin,Sinensetin,Nobiletin);Ferulic acid is mainly soluble phenolic acid in Nanfeng tangerine peel and pulp,and has high ferulic acid content in the early stage of ripening;Limonin was detected in the peel,flesh and orange nucleus of Nanfeng tangerine.No ketone was detected.The orange nucleus was rich in limonin and nomilin.The content of limonin in the peel was 403.34±1.46 μg./g DW ~1127.42±0.59 μg/g DW,the limonin in the peel and pulp showed a downward trend during the ripening process.(4)The dynamic changes of the aroma components and content of Nanfeng tangerine during the ripening process were detected by GC-MS.The results showed that the aroma components of Nanfeng tangerine fruit showed a decrease in the content of olefins and an increase in ester components during the ripening process.