Extraction And Activity Determination Of Polyphenols And Flavonoids From Dried Figs

Fig is a kind of medicinal and edible fruit tree species with a long history of cultivation.It is mainly preserved and processed in the form of dried figs.It is a kind of fruit product with wide development and application.Besides being eaten as whole fruit,it is also processed into industrial products such as ointments,concentrated juices,powders and granules.It is rich in minerals?calcium and potassium?,vitamins B₃,cellulose and phenolic compounds,with protective plasma lipoproteins,increase plasma antioxidant capacity,etc..Based on the active ingredients in dried figs,this study optimized the extraction process of polyphenols and flavonoids from dried figs,and evaluated the antioxidant and antibacterial activities of polyphenols and flavonoid extracts.The qualitative analysis of the phenolic compounds in the HPLC was used to develop and provide the theoretical basis and application basis for the extraction of dried fruit active substances.The results were as the followings:1.The determination of the extraction method of phenol and flavonoids in dried figs.Four polar solvent?ethyl acetate,n-hexane,chloroform,ethanol?was used to extract the phenols and flavonoids from dried fig fruits by the two different methods of one-time extraction and dual-solvent extraction,the total content of which were measured.At the same time,the antioxidant activity was compared by the scavenging activities against hydroxyl and reducing capacity evaluated.The results showed that,the content of total phenols and flavonoids by one-time extraction were higher than dual-solvent extraction,also with their antioxidant activity correspondingly.Using the same extraction method,the polarity of solvent extracts was greater,total phenols and flavonoids content of four different extracts was higher,the same as the trend of their antioxidant activity?ethanol extract>ethyl acetate extract>chloroform extract>n-hexane extract?.The extraction effect was the best when using 60%ethanol as extraction solvent through one-time extraction method,with the highest of the total phenols and flavonoids content and their scavenging activities against hydroxyl and reducing capacity.2.The extraction process of polyphenol and flavonoids from figs was optimized and the antioxidant capacity of the extracts was analyzed.The ultrasonic-assisted extraction of active substance from Dried Figs was optimized through the combined use of single factor method and response surface methodology.The optimal extraction parameters were found as follows:ethanol concentration,60%;extraction temperature,51?;extraction time,52 min,material/liquid ratio,1:45?g/mL?.The yield of polyphenols and flavonoids was?2.729±0.371?mg/g and?20.892±0.572?mg/g respectively under these conditions,also their antioxidant activities were evaluated and compared with Vc.The results showed that total reducing power,hydroxyl and DPPH free radical scavenging abilities of polyphenols was higher than Vc,but the super-oxide anion free radical scavenging abilities was lower than Vc,while the antioxidant activitity of flavonoids was lower than Vc.The present study also found that after treatment with artificial gastric and intestinal fluids,the index parameters of antioxidant activity of dried figs extractive were changed differently?p<0.05?,maybe related to the changes in the structure and function of polyphenols.3.The antibacterial activity of ethanol extracts of dried figs.The antibacterial activity of ethanol extract of dried figs on Salmonella,Staphylococcus aureus,Bacillus subtilis,Escherichia coli,Enterobacter aerogenes and Proteusbacillus vulgaris was determined by the oxford cup method.The results showed that,ethanol extracts of dried figs had significant inhibitory effect on Salmonella,Staphylococcus aureus,Bacillus subtilis,Escherichia coli and Enterobacter aerogenes,and the antibacterial activity increased with the increase of polyphenol concentration.The best bacteriostatic effect was Salmonella?38.7±0.42?mm,followed by Staphylococcus aureus,Bacillus subtilis,Escherichia coli,Enterobacter aerogenes.4.The analysis of the main phenolic substances in the ethanol extract of figs.Phenolic compounds and their contents in ethanol extracts of dried figs were studied.The results showed that the dried figs contained six compounds,gallic acid,4-hydroxybenzoic acid,chlorogenic acid,epicatechin,ferulic acid and rutin.They are all have high contents.The highest content of gallic acid was 3.02 mg/100 g among them.Followed by rutin,ferulic acid,epicatechin,chlorogenic acid and 4-hydroxybenzoic acid.