Studies On Isolation Identification And Bioactivity Of Polyphenols From Three Green Vegetables

In recent years,the problem of unmarketable vegetable is becoming more and more serious.This study aims to explore the bioactivity of green vegetable polyphenols.The ultrasonic-assisted extraction of total polyphenols from three green vegetables?spinach,celery,cabbage?were studied.On the basis of a single factor,using BBD experimental design principle,the liquid ratio,ethanol concentration,extraction time and temperature were optimized with the total polyphenols content as the evaluation index.Macroporous resin was used to purify vegetable polyphenols,and the polyphenol components were analyzed qualitatively and quantitatively by HPLC.At the same time,the antioxidant activities and its stability,antibacterial activities and its stability were also studied.The main results are as follows:?1?The optimization conditions of spinach,celery and cabbagewas the ratio of liquid to material:53:1?43:1?78:1?mL:g?.The volume of ethanol was 60%?50%?50%.The extraction time 40?30?40 min.Extraction temperature was 55??60??60?.The extraction recovery yield in spinach,celery and cabbage were 40.440 mg·g^-1,41.430 mg·g^-1,48.066 mg·g^-1.Cabbage polyphenols yield was the highest.?2?The spinach was selected D101 macroporous resin.The optimum conditions for the purification of spinach were as follows:loading concentration 0.550 mg·mL^-1,sample loading volume of 130 mL,with 50 mL of 60%ethanol?pH=5?to elute.In this condition,the purity of spinach polyphenols increased 19.581%to 70.006%.The celery was selected D101 macroporous resin.The optimum conditions for the purification of celery were as follows:loading concentration 0.992 mg·mL^-1,sample loading volume of 150 mL,with45 mL of 60%ethanol?pH=5?to elute.In the condition,the purity of celery polyphenols was increased from 20.378%to 55.570%.The cabbage was selected A-B8 macroporous resin.The optimum conditions for the purification of cabbage were as follows:loading concentration 0.463 mg·mL^-1,sample loading volume of 100 mL,with 40 mL of 60%ethanol?pH=7?to elute.Under the condition,the purity of cabbage polyphenols increased21.550%from 85.360%.?3?Five kinds of phenolic of gallic acid,chlorogenic acid,caffeic acid,ferulic acid and rutin were selected as standard products by high performance liquid chromatography.The spinach contained 0.2993 mg·g^-11 gallic acid,0.2445 mg·g^-11 ferulic acid and 0.3179mg·g^-1rutin.The celery contained 0.2137 mg·g^-1gallic acid,1.8524 mg·g^-1chlorogenic acid,10.1984 mg·g^-1caffeic acid and 1.1423 mg·g^-1ferulic acid.The cabbage contained0.7875 mg·g^-11 gallic acid,5.5667 mg·g^-11 chlorogenic acid,1.0112 mg·g^-11 caffeic acid,1.7555 mg·g^-1ferulic acid and 14.2172 mg·g^-1rutin.Celery polyphenol has the highest content of caffeic acid.In cabbage polyphenol,chlorogenic acid and rutin are the main ingredients.?4?The antioxidant capacity of three green vegetables polyphenols in vitro were evaluated by DPPH radical scavenging method and ferric reducing antioxidant powder?FRAP?method.The results showed that the antioxidant activity of celery and cabbage polyphenols were strong,and spinach was weak.The study suggests that three green vegetables?spinach,celery,cabbage?polyphenols have good antioxidant properties,but need to pay attention to control the impact of the external environment,and enhance the use of results.?5?The antibacterial activity of vegetables polyphenols against common pathogens were observed by Oxford cup method and spread plate method.The results showed that the spinach polyphenols on Escherichia coli,celery polyphenols on Bacillus subtilis,cabbage polyphenols on Staphylococcus aureus had strong antimicrobial activity and had better antimicrobial stability.Vegetables are rich in polyphenols,which have good antioxidant activities and bacteriostasis.They can be used as natural antioxidants and preservatives.