Investigation On The Inhibitory Effect And Preliminary Mechanism Of Anthocyanins On Formation Of Endogenous N-nitrosamines

N-nitrosamine is one of the four major food contaminants，which is a strongcarcinogenic contaminant，Under the detrction method and the formation mechanismhaving become mature，inhibiting the form of N-nitrosamines and reducing its harm tohumans and the environment is the direction of the research now．Using exogenous foodadditives，food ingredients and phytochemicas is the main measure to control nitrosamineformation in the food，as natural antioxidant，bioflavonoids which extract from plant oninhibitory effect on the formation of nitrosamines is a hotspot．The research regard thethree representative N-nitrosamines-NDMA，NDEA（aliphatic symmetry nitrosamines），NPYR （five yuan heterocyclic asymmetric nitrosamines）as the research object，on thebasis of high performance liquid chromatography tandem mass spectrometry（LC-MS）method， optimize NDMA，NDEA，NPYR synthetic conditions under the condition ofsimulated gastric juice in vitro （pH3，37℃），further study the influence of flavonoidpolyphenol compounds-grape anthocyanins on the formation of N-nitrosamines，and usethe LC-MS technique to discus the mechanism of grape anthocyanins inhibitingN-nitrosamines synthesis．The main results were as follows：1．The experiment used HPLC method to quantitative analysis for three kinds ofN-nitrosamines：Under the simulated condition of gastric juice in vitro，respectivelydifferent substrates was studied on the influence of the concentration of N-nitrosaminesgeneration，the results show that the optimal concentration of0.02mol/L dimethylaminehydrochloride，0.04mol/L diethylamine，0.04mol/L pyrrolidine react with sodium nitriteto1:1equivalent respectively，the content of NDMA，NDEA and NPYR is in theconcentration of the standard curve of the linear range，the results are accurate．2．Select the grape anthocyanins as inhibitor to study the formation dynamics of threekinds of N-nitrosamines．According to concentration-response relationship，under thecondition of simulated gastric juice in vitro（pH3.0，37℃），when the concentration ofgrape anthocyanins solution added for7mg/mL，the inhibitory rate of NDMA is70.0%； Add grape anthocyanins concentration to14mg/mL，57.1%NDEA can be blocked；To join14mg/mL grape anthocyanins solution in the reaction system，the inhibitory rate of NPYRis56.1%．Based on the best grape anthocyanins adding dose levels，kinetic model of grapeanthocyanins inhibiting N-nitrosamines is established，drawing the kinetic profiles of threekinds of N-nitrosamines，first order kinetics equation is established and calculate kineticparameters．The results show that the formation process of three kinds of N-nitrosaminesare in line with the first order kinetics model，at the same time the grape anthocyanins hassignificant inhibitory effect on them．3．According to compare different addition amount of grape anthocyanins for higherremoval clearance on sodium nitrite，and finally8.0mg/mL grape anthocyanins was pickedout for removal sodium nitrite，clearance rate can reach96.2%．By LC-MS the mechanismof grape anthocyanins eliminating sodium nitrite were studied simultaneously．The resultsshow that the mechanism of sodium nitrite and grape anthocyanins reaction may be five orseven phenolic hydroxyl group was replaced by the nitroso．Thus the reaction mechanismof grape anthocyanins and N-nitrosamines can be deduced: under the condition of weakacid，nitrous acid appeared by combing hydrogen ions with nitrite，grape anthocyanins hasa strong ability to replace the nitroso，consuming the amount of nitrite，indirectly reducethe sodium nitrite，reduce the concentration of premise material，thus inhibiting thesynthesis of N-nitrosamines．...