Study On The Extraction, Separation And Purification Of The Antioxidant Functional Components Of Eucommia Ulmoides

Eucommia ulmoides Oliv.is a unique and precious traditional Chinese Medicine in China,which is mainly composed of bark,leaf and fruit.There are abundant natural active components in Eucommia ulmoides,so far,about 205 compounds have been isolated.They have many pharmacological effects,such as lowering blood pressure,blood glucose and lipid,preventing osteoporosis,antibacterial,anti-inflammatory,anti-tumor,antioxidant and so on.It’s fruit consists of kernel and pericarp,which is mainly used to extract Eucommia seed oil,After the extraction of Eucommia seed oil,the peel was Extracted the Eucommia gum,which is discarded or simply used.but in fact,the pericarp is still rich in natural active ingredients with biological activity and medicinal value,such as aucubin,geniposide acid,chlorogenic acid,flavonoids and so on.Therefore,the natural active ingredients were extracted and purified from the peels,turning waste into treasure,it can not only reduce the waste of agricultural resources,greatly increase the income of forest farmers,but also dilute the production costs of Eucommia gum and eucommia products,so as to promote the sustainable development of China’s Eucommia ulmoides industry.1.In order to increase the yield of aucubin,geniposide and chlorogenic acid,complete extraction should be realized as far as possible.The peels of Eucommia wings were used as raw materials,the effects of five enzymes(acid xylanase,laccase,neutral xylanase,hemicellulase and alkaline xylanase)on the extraction were investigated.The results showed that the acid xylanase was the best enzyme for the extraction of aucubin,geniposide acid and chlorogenic acid from the peel.To investigate the effects of different enzyme dosage,p H,temperature and time on the enzymatic hydrolysis effect,and the enzymatic hydrolysis conditions were optimized by orthogonal design,the results showed that the optimum conditions were as follows:enzyme dosage 6%,p H 4.8,temperature45℃,time 8 h.Under these conditions,the yield of aucubin,geniposide acid and chlorogenic acid was 53.57μg/g,567.42μg/g and 41.69μg/g,respectively.The total yield was 662.69μg/g,which was 7.7 times higher than that of the sample without any enzymatic hydrolysis.The above optimum conditions were applied to the practical step-by-step continuous enzymatic hydrolysis test,the results showed that the contents of aucubin,geniposide acid and chlorogenic acid increased by 7.45μg/g,63.97μg/g and 6.93μg/g respectively after adding acid xylanase.2.In order to comprehensively investigate the"refining"effect of microfiltration(MF),ultrafiltration(UF),nanofiltration(NF)and reverse osmosis(RO)membranes,the separation membrane was used to remove most impurities before concentration,so as to reduce membrane pollution and improve the yield of effective components.After the enzymolysis extract of Eucommia ulmoides wing peel was treated by microfiltration membrane and ultrafiltration membrane separately or in combination.To investigate the refining effect of 9 treatment methods on Eucommia ulmoides enzymatic hydrolysate,including microfiltration,ultrafiltration,microfiltration+ultrafiltration,microfiltration+nanofiltration,microfiltration+ultrafiltration+nanofiltration,microfiltration+reverse osmosis,ultrafiltration+reverse osmosis,microfiltration+ultrafiltration+reverse osmosis.The weight of main evaluation indexes(W_j)was calculated by the entropy weight method and the comprehensive score(Y)was calculated.The results showed that the comprehensive score of ultrafiltration method was the highest among the three separation methods,after the three separation methods were combined with nanofiltration and reverse osmosis membrane,the comprehensive score of ultrafiltration+reverse osmosis was the highest.It is concluded that ultrafiltration+reverse osmosis can be used as the best process for enzymatic hydrolysis of Eucommia Samara extract.The results obtained by this method are as follows:the protein removal rate was 99.02%,starch removal rate 57.42%,pectin removal rate 50.16%,tannin removal rate 51.15%,solid removal rate 26.29%,the yields of aucubin,geniposide acid and chlorogenic acid were 80.63%,79.18%and 45.49%,respectively.After the membrane separation,the color of the sample was improved obviously,and the clarity was higher.3.On the basis of the optimal separation and purification process,to investigat the effects of feed temperature,operating pressure,operating frequency,membrane passing time,feed concentration and feed p H on the ultrafiltration purification process,and to optimize the ultrafiltration process by Box-Behnken response surface method.The results showed that the optimum conditions were as follows:the feed temperature was 35℃,the operating pressure was 0.5 MPa,the operating frequency was 35 Hz,and the film passing time was 42 min,under these conditions,the transfer rates of aucubin,geniposide acid,chlorogenic acid and solid removal rates were 93.54%,82.36%,58.15%and 70.89%,respectively,compared with that before optimization,it increased by 1.55,1.32,1.66 and1.58 times respectively.4.In order to investigate the effect of membrane separation method on the antioxidant activity of the samples in vitro,the samples were prepared under the established purification process and the optimal conditions,and their antioxidant activity in vitro was determined,objective to investigate the effect of membrane separation on antioxidant activity of Eucommia ulmoides extract in vitro.Compared with the original solution of enzymolysis extract,after ultrafiltration treatment,the ABTS free radical scavenging rate,DPPH free radical scavenging rate,hydroxyl free radical scavenging ability and superoxide anion inhibiting ability of Eucommia ulmoides extracts with different concentrations decreased,but the ultrafiltration sample was further concentrated by reverse osmosis,the ABTS free radical scavenging rate,DPPH free radical scavenging rate,hydroxyl free radical scavenging ability and superoxide anion inhibiting ability of the extract were higher than those of the ultrafiltration extract.The results show that the concentration of reverse osmosis membrane can effectively improve the antioxidant capacity of ultrafiltration extract,and maintain high antioxidant activity.It further shows that ultrafiltration+reverse osmosis treatment is feasible in the"refining"of Eucommia ulmoides enzymatic hydrolysate system.