The Study On Scavenging Nitrite And Blocking Nitrosamine Synthesis By Anthocyanins In Vitro

Anthocyanins,also known as flavonoids,is one of the natural antioxidants.Cyanindin-3-glucoside and Vitisin A are monomer anthocyanins and anthocyanin derivatives(pyrano-type anthocyanins)commonly found in nature.Anthocyanins have a variety of biological functional activities and excellent antioxidant properties.This research uses high purity C3G and Vitisin A made by laboratory to analyse the physical and chemical properties of anthocyanins.In particular,this research examines the stability and antioxidant activity of anthocyanins in order to explore the blocking synthesisof endogenous and exogenous nitrosamine;the mechanism of the anthocyanins blocking synthesis,providing theoretical basis for using the anthocyanins as food additives.The main researches are as follows:1.The stability of anthocyanins is related to its chemical structure,and Vitisin A is more stable than C3G.As the p H value increased,the maximum characteristic absorption wavelength of C3G changed from 511 nm to 380 nm while the color changed from red to light pink to yellow.When Vitisin A changed from 500 nm to 480 nm,the solution showed a light red color.The color loss of C3G in sulfur dioxide solution was 71%while that of Vitisin A was 10%.The half-life of Vitisin A was 2.82 h at 98?,which was 1.45 times more than C3G.There was not significant effect between at 40?.The UV light loss of Vitisin A was 136%lower than C3G.2.The antioxidant capacity of anthocyanins was determined by ABTS,DPPH free radical assay and?-carrot bleaching assay.The ABTS and DPPH radical scavenging abilities of C3G was 1.56 and 1.71 times higher than Vc,Vitisin A was 1.77 and 1.70 times higher than Vc,respectively.The antioxidant activity of Vitisin A was worse than that of C3G by?-carrot bleaching method.3.C3G in the high nitrite and high protein simulated diet showed the higher the concentration of C3G,the lower the nitrite content,can reduce 50%nitrite.Five kinds of nitrosamines were detected by GC-MS and SPE extraction in the simulated diet vitro digestion:NDMA,NMEA,NDEA,NMVA,NPYR.C3G can reduce the production of nitrosamines by5-6.5%,and can reduce the production of endogenous nitrosamines.4.The commercial value of adding anthocyanins into cantonese sausage as anthocyanins was evaluated by multiple indexes(nitrite residue,p H value,malondialdehyde value,chromaticity value,microbial content).As for the Cantonese sausage with anthocyanin and sodium nitrite,it had a advantage of color,antioxidantion.It could reduce the content of nitrite by more than 33%and the content of malondialdehyde.Adding 50 mg/kg Na NO₂ 100 mg/kg C3G was a better addition ratio.Therefore,anthocyanins can be used as food additives to reduce the content of exogenous nitrosamines in food.5.The blocking synthesis of nitrosamines was investigated by HPLC-MS.Using anthocyanins,sodium nitrite and dimethylamine simulation system,it was proved that the nitrosamine blocking rate of C3G was 1.15 times more than Vitisin A,and the sodium nitrite clear rate of C3G was 1.20 times more than Vitisin A.HPLC-MS showed that C3G could block the formation of nitrosamine by binding nitrite and C5-OH and C7-OH on the parent ring of C3G reacted with nitrite to form the binder.The mechanism of anthocyanins blocking nitrosamine synthesis was reducing nitrite in the solution and blocking the binding of nitrite and dimethylamine,thus blocking the generation of N-dimethylnitrosamine.