| Our country has many resource,especially in rose.In this article,rose from Lijiang Yunnan is used as materials,and the polyphenols in roses were extracted by ultrasonic-assisted extraction.The extraction conditions were optimized by response surface methodology.The bacterial properties and in vitro antioxidant properties are good,and the main results are as follows:(1)The investigation of polyphenols from rose has been experienced.Ultrasonic power,solid-liquid ratio,ethanol concentration,temperature and time were selected.The selected conditions were obtained: the solid-liquid ratio was 1:27 g/m L,the ultrasonic power was 550 W,and the volume fraction of ethanol was 50 %,under this condition,the polyphenol content of rose flower was 0.956 %.(2)From the screening of 7 kinds of macroporous resins with different polarity and different particle size ratios,it was found that D101 macroporous resin is the most suitable purified resin for rose polyphenols through adsorption tests,with an adsorption rate of 96.46 % and a desorption rate of 53.06 %.Through static adsorption,desorption and dynamic experiments,t-he optimal process was determined to be: the loading mass concentration was 2.5 mg/m L,s-ample loading p H 3,the ethanol volume fraction 80 %,the loading flow rate was 2 m L/min,and elution liquid volume was 160 m L.The purity was increased from 17.16 % to 58.12 %and the purity became 3 times than before.(3)There was a dose-effect relationship between the concentration and total reducing power,DPPH radical,ABTS+ radical,hydroxy radical scavenging ability of polyphenols from rose.The scavenging ability of DPPH free radical was as follows: unpurified crude polyphenols(59.75 %)< TBHQ(65.41 %)< purified polyphenols(73.67 %)< VC(95.71 %),IC50 value were 65.59 ?g/m L,51.12 ?g/m L,38.66 ?g/m L,20.47 ?g/m L.The scavenging ability of hydroxy radical was as follows: VC(10.59 %)< unpurified crude polyphenols(13.06 %)unpurified crude polyphenols>VC.The purified polyphenol solution is purplered,and the solution is clear and free of impurities.It can be seen from the above results that in the comparison of the antioxidant capacity of rose polyphenols and Vc before and after purification,it can be seen that the antioxidant capacity of rose polyphenols after purification is significantly enhanced,and the greater the mass concentration of polyphenols,the stronger the antioxidant capacity.(4)Before the purification of rose flower,polyphenols showed different bacteriostatic activities on 7 experimental bacteria.It had a good inhibitory effect on bacteria,and did not show inhibitory effect on fungi.The purified polyphenols also have an inhibitory effect on the above bacteria at the same concentration,and the inhibition effect is stronger than that of the prepurification polyphenols.Rosette polyphenols have good bacteriostatic properties,and the mi-nimum inhibitory concentrations of rose polyphenols on Staphylococcus aureus,Budella subtilis,Escherichia coli,Salmonella enteriditis and Listeria monocytogenes are3.75,4.28,5.00,2.00 and 1.00 mg/m L,respectively.Compared with potassium sorbate,rose polyphenols are more bacteriostatic than potassium sorbate.Through temperature and p H experiments,rose polyphenols are sensitive to temperature and p H,and rose polyphenols also have a strong bacteriostatic effect at hi-gh temperatures;the bacteriostatic effect of rose polyphenols under acidic conditions is relatively stable,and the bacteriostatic effect under alkaline conditions is unstable and weaker than that under acidic conditions. |
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