Effect And Applications Of Enzymes And Citric Acid Commonly Used In Pasta Processing On The Degradation Of Aflatoxin B₁ And Deoxynivalenol

In recent years,China has made great progress in rapid detection of mycotoxins,early monitoring and early warning of fungi and toxins in stored grain,inhibition and removal of stored grain fungi and toxins.However,the research on the transformation of mycotoxins in the food processing is still in its infancy,which may due to the complexity of food processing and food components.In this study,the common enzymes and citric acid in pasta products were selected as the research objects of food single component,and the effects of the above components on aflatoxin B₁（AFB₁）and deoxynivalenol（DON）in cereals were studied in order to provide theoretical guidance for the rational use of food processing and the degradation of mycotoxins,the main progress of this study is as follows:1)It was found that four kinds of enzymes commonly used in pasta processing had degradation effect on AFB₁.The degradation rates of AFB₁ byα-amylase（5000U）,xylanase（2500 U）,hemicellulase（1000 U）and glucose oxidase（0.24 U）were20.93±14.94%,70.12±4.39%,2.47±5.8%and 48.09±2.48%,respectively.Similarly,the above four enzymes can degrade DON in medium gluten flour,high gluten flour and low gluten flour.Among them,hemicellulase（2500 U）has the highest degradation rate of DON in low gluten flour,reaching 64.78±1.26%,and hemicellulase（2500 U）has the same degradation rate of DON in medium gluten flour.It is suggested that hemicellulase and xylanase may be good degradation enzymes of DON and AFB₁,respectively.UPLC-TOF/MS method was used to analyze the DON degradation products.Due to the complexity of flour and enzyme matrix,the ion diagram of DON degradation products could not be effectively identified in the total ion flow diagram.Further research is needed in the future.2)It is confirmed that the mixture of citric acid and iodine can degrade AFB₁ and produce three new products,which are P1（m/z=329.06）.),P2（m/z=456.97）and derived AFB₁（m/z=347.07）.The treatment of iodine plays a vital role in the degradation of AFB₁ by citric acid.Based on the analysis results of Peak View,the mass spectrometry software of AB Sciex,we infered that the possible molecular formula of P1（m/z=329.06）is C₁₇H₁₃O₇,and the possible molecular formula of P2（m/z=456.97）is C₁₇H₁₄O₇ and the possible molecular formula of derived AFB₁（m/z=347.07）is C₁₇H₁₅O₈.It is speculated that iodine derivatizes AFB₁ to m/z=347.07,and then the derived AFB₁（m/z=347.07）with the participation of citric acid is dehydrogenated to P1（m/z=329.06）,at the same time,one of the hydroxyl groups of derived AFB₁（m/z=347.07）is replaced by iodine to formed P2（m/z=456.97）.