Study On The Extraction, Purification And Biological Activity Of Sand Mustard Nutrient Components And Sand Mustard Polyphenols

As a wind-proof and sand-fixing plant,P.cornutum(L.)Gaertn.not only has good ecological benefits,but also is a kind of wild food resource and has certain edible value.The study was conducted to investigate the nutrient composition of P.cornutum(L.)Gaertn.and confirm its nutritional value.In addition,ultrasound-assisted extraction of P.cornutum(L.)Gaertn.Polyphenols,and its separation and purification was carried out by macroporous resin.Preliminary antioxidative activity and antibacterial activity were then studied.The results can be used to provide reference for the development and utilization of P.cornutum(L.)Gaertn.The results of the study were as follows:(1)Analysis of nutrients in the P.cornutum(L.)Gaertn.The national standard method was used to determine the composition and content of basic components,mineral elements,vitamins and amino acids of P.cornutum(L.)Gaertn.,and compare it with common five kinds of vegetables.The results showed that the P.cornutum(L.)Gaertn.is nutritious and can be eaten as wild vegetables.Among them,the moisture content of P.cornutum(L.)Gaertn.was 88.97%.Analyzed by dry matter of P.cornutum(L.)Gaertn.,the main substance in P.cornutum(L.)Gaertn.was dietary fiber(40.89%),followed by protein(26.87%).The content of fat and total sugar were relatively lower.In addition,the content of Vc(134.61 mg/100 g)and mineral elements in P.cornutum(L.)Gaertn.were higher,especially Ca(58.98×103 mg/kg)and K(50.32x103 mg/kg),all of which were higher than five common vegetables.A total of 232.99 mg/g of 17 amino acids were detected in P.cornutum(L.)Gaertn.,of which the essential amino acids accounted for 42.24%of the total.The first limiting amino acid of P.cornutum(L.)Gaertn.was isoleucine,and P.cornutum(L.)Gaertn.was an ideal wild vegetable resources.(2)Extraction of polyphenols from P.corntum(L.)Gaertn.The single-factor test basis combined with response surface optimization was used to optimize the ultrasonic-assisted extraction of P.cornutum(L.)Gaertn.polyphenols.The material-liquid ratio,ultrasonic time,ultrasonic power,and ultrasonic temperature were the influencing factors.With the extracted quantity as the response value,four-factor and three-level design experiments were performed.According to the regression equation verification model,the optimum conditions for the extraction of polyphenols from P.cornutum(L.)Gaertn.were obtained,the ratio of material to solution was 1:19 mg/L,ultrasonic time was 30 minutes,ultrasonic power was 291 W,ultrasonic temperature was 55?,and the extraction amount of P.cornutum(L.)Gaertn.was 3.46 mg/g.(3)Separation and purification of P.cornutum(L.)Gaertn.polyphenols by macroporous resin.By comparing the adsorption and desorption effects of 10 macroporous resins of different types on P.cornutum(L.)Gaertn.,D101 macroporous resin was selected to isolate and purity the polyphenols.Through a static and dynamic adsorption and desorption test,a sample of 1.45 mg/mL P.cornutum(L.)Gaertn.polyphenols was selected and uniformly distributed into the macroporous resin layer at a flow rate of 1.5 BV/h.After saturation adsorption,elution was carried out with a 70%ethanol solution at a flow rate of 1.5 BV/h.The content of polyphenols after purification was 2.34 times that before purification,and the resin utilization performance was high.A preliminary composition analysis was conducted on the purified P.cornutum(L.)Gaertn.polyphenols before and after purification by HPLC.The purified monophenols of the P.cornutum(L.)Gaertn.polyphenols were all preserved,mainly including gallic acid,protocatechuic acid,chlorogenic acid,p-hydroxybenzoic acid,caffeic acid,p-coumaric acid,ferulic acid and protocatechuic acid accounted for the main component,followed by chlorogenic acid and p-hydroxybenzoic acid.(4)Antioxidant activity of P.cornutum(L.)Gaertn.polyphenols.Determination of the total reducing capacity of P.cornutum(L.)Gaertn.before and after purification of D101 macroporous resin,and the scavenging abilities of hydroxyl radicals,DPPH radicals and superoxide anion radicals were studied,and Vc was used as a control.The results showed that the antioxidation activity of P.conutum(L.)Gaertn.polyphenols were increased with the increase of the concentration in the determination of the above four indicators,and the antioxidation activity of the purified polyphenols was higher than that before purification.At a certain concentration,part of the activity is close to the antioxidant activity of Vc.(5)Antibacterial activity of P.cornutum(L.)Gaertn.polyphenols.The oxford cup method was used to study the antibacterial effect of P.cornutum(L.)Gaertn.against Escherichia coli,Bacillus subtilis,and Staphylococcus aureus.The results showed that P.cornutum(L.)Gaertn.had antibacterial activity against the above three bacteria,and its minimum inhibitory concentration(MIC)was 2.5 mg/mL,1.25 mg/mL,and 2.5 mg/mL,respectively.