Effects Of Ozone And Electron Beam Irradiation On Degradation And Quality Of ZEN And OTA-contaminated Corn

Zearalenone(ZEN)and ochratoxin A(OTA)are common fungal toxins in agricultural products,which are closely related to human and animal health and agricultural economy.Corn is one of the most important crops in China and even the world.Due to environmental,ecological and storage factors,corn can be contaminated with mycotoxins such as ZEN and OTA.The research on the detoxification technology of mycotoxins in agricultural products has been paid much attention.There are physical,chemical and biodegradation methods of ZEN and OTA.However,there are problems such as the low degradation rate,solvent residue and high cost.Therefore,it is necessary to find a safe and efficient method for degrading ZEN and OTA.In recent years,ozone and electron beam irradiation(EBI)technology has been gradually applied to food sterilization and food preservation.Besides,there are some studies to utilize ozone and EBI technology to reduce mycotoxins,especially for AFB1.In this paper,ZEN and OTA were degraded by ozone and EBI.The effects of ozone and EBI on the degradation of ZEN and OTA in corn were studied under different conditions.The kinetics of degradation was studied.The physical and chemical properties and the toxicity of corn after ozone and EBI treatment were evaluated.This study provides the theoretical and practical basis for the application of ozone and EBI on the degradation of ZEN and OTA.The main results of the study were as follows:Degradation of ZEN and OTA by ozone and EBI.The effects of ozone concentration,treatment time and irradiation dose on the degradation of ZEN and OTA were investigated.When the concentration of ozone was 10 mg/L,ZEN was undetectable by HPLC in 5 s,and OTA was reduced by 65.4% in 120 s.The degradation rate of 0.5 ?g/mL ZEN and OTA were 65.6% and 68.2%,respectively,when the irradiation dose was 10 kGy.Effects of ozone and EBI on the degradation of ZEN and OTA in corn and the kinetic model.The results showed that when the ozone concentration was 100 mg/L,and the treatment time was 180 min,the degradation rate of ZEN and OTA in corn of 14.1% moisture content was 86.0% and 64.2%,respectively.When the moisture content was 19.6%,the degradation rates were 90.7% and 70.7% respectively at the same condition.The degradation rate increased with the irradiation dose,and the degradation efficiency of corn kernel was better than that of corn flour.When the irradiation dose was 50 k Gy,the degradation rates of ZEN and OTA in corn of 13.9% moisture content were 71.1% and 67.9%,respectively.When the moisture content increased to 19.1%,the degradation rate increased at the same dose.The results of ZEN and OTA degradation by ozone and EBI showed that the degradation of ZEN and OTA in corn was in accordance with the first order kinetic model.For the degradation by ozone,the reaction rate constants of ZEN and OTA in kernels were k100 mg/L>k80 mg/L>k60 mg/L>k40 mg/L.For the degradation by EBI,the reaction rate constants of ZEN and OTA were kcorn grain>kcorn flour.In addition,the degradation rate of ZEN and OTA was found to be most suitable for polynomial fitting at different time and doses.Effects of ozone and EBI on physical and chemical properties of corn.The physical and chemical properties of corn polluted by ZEN and OTA showed that the moisture content of corn kernels decreased from 14.1% to 13.2% after 100 mg/L ozone treatment;The L* value of corn increased and the a* and b* values decreased;The free fatty acid value increased,but was still in line with national standards;Starch gelatinization characteristics changed significantly;Amino acid showed no significant change.After 50 kGy EBI,the moisture content of corn decreased;The a* and b* value decreased;Free fatty acid value increased,but was still in line with national standards;Starch gelatinization characteristics showed significant changes.The total amount of corn amino acids decreased significantly.Compared with ozone,EBI had a more severe effect on the physical and chemical properties of corn kernels.Safety evaluation of degradation of ZEN and OTA by ozone and EBI.The vivo toxicity experiment of ICR mice showed that there were no significant differences in body weight,organ weight and organ coefficient among the groups.Blood biochemical indexes indicated that the levels of ALT,AST,and AST in the mice fed with mycotoxins contaminated corn feed were significantly higher than those in the normal corn feed group(p<0.05),BUN and SCr were significantly increased(p<0.05),while TP and ALB were significantly decreased(p<0.05).Histological lesions were observed in the liver,and no histological lesions were observed in the kidneys.The blood biochemical indexes were significantly improved as well as the histopathological change of the liver in the ozone and EBI treated corn feed group.