Study On Extraction And Inhibition Of Nitrosation By Flavonoids From Onion

In this study, purple onion as the main research object, extraction of onion flavonoids wereextracted by ethanol, through single factor experiment and response surface experiments theoptimal extraction conditions were determined, and then resin for separation and purification oftotal flavone of onion extract obtained by large hole, and the onion Huang Tongqing in additionto nitrite and blocking the ability of the formation of nitrosamines are determination of.The results show that:1.The optimum extraction conditions of flavonoidsThis experiment with ethanol as the extraction of onion flavonoids, measure absorbanceextract rutin standard curve, according to the onion flavonoids yield, this measure, by singlefactor experiment and response surface optimization of extraction conditions of onionflavonoids test. The analysis and optimization of response surface experiments to obtain theoptimum extraction conditions of total flavonoids from onion: extraction temperature50℃,extraction time4h, ratio of solid to liquid1:4, alcohol concentration65%. Three parallel testswere carried out under this condition, the average to flavonoids was4.14%.2.Separation and purification of onion flavonoidsUsing macroporous resin chromatography of extracts of onion flavonoids separation andpurification. Through the static adsorption and desorption experiments, choose the ADS-8typemacroporous resin, with70%ethanol as the desorption of onion flavonoids were isolated bynight. According to the research results, first with double distilled water, water solubleimpurities, the direct use of70%ethanol solution for elution, the onion flavonoids extractflavonoids purity of96.22%.3.Remove nitrite and disconnecting nitrosamine generating capacity determination(1)With the increase of concentration of total flavone of onion, and its ability to scavengenitrite has gradually increased, when the concentration of flavonoids reached0.08mg/mL,clearance rate reach the maximum, approximately83.70%, and then increases the onionflavonoids concentration, clearance rate unchanged, the total flavanone of onion, maximumclearance of nitrous acid salt rate is about83.70%.(2)With the increase of the concentration of flavonoids, blocking the ability of itsgeneration of nitrosamines is increasing gradually, when the concentration of flavonoidsincreased to0.08mg/mL, blocking rate is about94.39%, the largest, blocking the ability of flavonoids concentration increases again after basically unchanged, visible, onion flavonoidsformation of nitrosamine most big block rate was94.39%。(3)The same concentration of onion flavonoids and Vc, flavonoids are significantly largerthan Vc.(4)The same concentration of onion flavonoids crude extract and extract, although the totalflavanone of onion flavonoids crude extract purity liquid is lower than that of the extract, but thescavenging nitrite and disconnecting nitrosamine generating capacity is higher than the extract.