Extraction And Purification Technology Of Flavonoids From Hops

The vast majority of plants in the world contain flavonoids,it is common with tea flavonoids,ginkgo flavonoids and so on.Such compounds play an important role in the process in the plant growth.Pharmaceutical study shows that flavonoids have a high antioxidant capacity and the effect of reducing the incidence of cardiovascular disease.Hops contain a large number of flavonoids too,and the extraction of flavonoids from hops and purification process has a great significance to its deep processing.Extraction and purification technology of flavonoids from hops were studied in this thesis.Three different polar organic solvents using in the static test,soxhlet extraction,sltrasonic extraction,microwave extraction and supercritical extraction were studied,and the optimum extraction conditions were obtained.Finally,with the help of D101 macroporous resin,we obtained purified flavonoids.Using rutin as the standard test reference substance,crude flavonoids content of the samples were detected by the UV spectrophotometor.The results showed that the highest flavonoids content was from ethanol extraction of hops,and the best extraction conditions were as follows: The concentration of ethanol was 60 %,the extraction time was 2 min,the ratio of hops to extractant 1: 30,power 80 W,and the content of flavonoids was 3.013 %.The macroporous resin was used to separate and purify the flavonoids from hops.The loading speed of sample solution(flavonoids crude extract)is 3 mL/min,flavonoids can be eluted from the resin using 75% ethanol solution.The elution rate was1.5mL/min and the eluent concentration was obtained as 0.018 mg/mL.The purification ratio of flavonoids was 81.82%.According to the structure verification,it is found that the method has a good results on the extraction of flavonoids from hops.The research results of this paper will provide a theoretical basis for the extraction and purification of various natural active ingredients from hops,and contribute to the deep processing of hops products and added value of the agricultural products.