Influence Of Fumigation On The Antioxidant Activity And The Antibacterial Activity Of Shanxi Aged Vinegar

The fumigation is a unique process in the production of Shanxi aged vinegar,it givesthe vinegar color,aroma and functional activity.The study selected aged vinegarfumigated as the research object,focus on the change rules of antioxidant activity andbrowning degrees and acrylamide content in vinegar during three kinds of fumigatingprocess,separated and purified the melanoidin of vinegar by ultrafiltration and sizeexclusive chromatography?SEC?,established a SEC separation method that can separateand identify melanoidin simultaneously,explored DNA oxidation resistance andantibacterial activity of melanoidin separated by SEC.The main research contents and conclusions were as follows:?1?Exploring the change rules of antioxidant activity and browning degrees andacrylamide content in vinegar,the vinegar were from three kinds of different productionscale fumigated technology in the fumigation workshop of the company.The resultsshowed that on the basis of traditional charcoal fire fumigation?80-90?,5days?,usingsteam fumigation and improving the temperature to 100? or 120? the time wereshortened by 2 or 4 days,DPPH· scavenging rates were increased by 13.1%or 19.8%,reducing powers were increased by 77.8%or 64.8%,the browning degrees were increasedby 78.0%or 64.8%.The acrylamide were not detected in non-fumigation or lowtemperature?90??fumigation.The acrylamide was detected in 100? steam fumigationfor one days,the content is lower and increased slowly?4.70-5.20?g/L?with the passageof time?1-3 days?.The content of acrylamide was increased sharply?0-15.41 ?g/L?in 120?steam fumigation for one days.DPPH· scavenging rates,reducing powers and browningdegrees in each stage of three kinds of fumigating process were significantly positivecorrelation on 0.01 level.Accordingly,melanoidin generated by fumigation may be thefunctional factors of vinegar antioxidant activity.100?-3d steam fumigation technologyis worth to recommending.?2?Separating melanoidin by ultrafiltration-SEC method and mensuratingsimultaneously the contents of total sugar?Abs 490nm?,protein?Abs 280nm?andbrowning degree?Abs 420nm?in the collected fractions,establishing a SEC separation method that can separate and identify melanoidin simultaneously.Qualitative analysis ofmelanoidin?M>3?separated is by ultraviolet-visible spectral scanning,the characteristicsof M>3 ultraviolet-visible spectra fits that of melanoidin,which confirms M>3 ismelanoidin.M>3 has a good protective effect on DNA oxidative damage caused byCu?II?-Vc system and there is a certain dose effect relationship.Accordingly,melanoidinof aged vinegar has significant biological antioxidant activity.?3?Comparing the determination results of the filter method and turbidimetricmethods,the results showed that sensitivity and precision of the turbidimetry method werebetter than that of the filter method.Determinating the bacteriostatic activity of differentmolecular weight melanoidin?M>3,M3-5,M5-10 and M>10?by turbidimetric method,theresults showed that the antibacterial rates of M3-5 on Escherichia coli,staphylococcusaureus,bacillus subtilis?69%,78%and 75%?were significantly higher than that ofvinegar powder?48%,66%and 62%?with the same concentration?4mg/mL?.Accordingly,melanoidin in vinegar powder plays a major role in the bacteriostatic activity.Theantibacterial rates of M3-5 on escherichia coli,staphylococcus aureus and bacillus subtilis?80%,88%and 85%?were significantly higher than that of M>10?60%,70%and 66%?and M5-10?40%,55%and 48%?,the results showed that the antimicrobial activity of M3-5was the strongest in different molecular weight melanoidin.The growth curve of threebacteria under different M3₅ concentration showed that melanoidin inhibits the growth ofbacteria and prolongs lag phase and drops the growth rate obviously.Under theexperimental condition?the bacteria concentration of system was 105cfu/mL?,the minimalinhibitory concentration?MIC?of M3-5 on Escherichia coli was 4.5mg/mL?the MIC ofM3-5 on Staphylococcus aureus and Bacillus subtilis was 3.5mg/mL.Estimateingmelanoidin content of vinegar products sold,the results showed that bacteriostatic effectof melanoidin can't be ignored in vinegar.