Residual And Dietary Exposure Assessment Of Alternaria Toxins In Commercially Available Wheat Products

Alternaria can cause wheat black point disease and produce a new type of emerging fungal toxin — —Alternaria toxins.Alternaria toxins can seriously affect the quality of agricultural products,thus posing a threat to human and animal health.Alternaria toxin contamination is widespread and severe,but the contamination status of wheat flour and its products in Anhui Province is unclear,and the risk of dietary exposure is unknown,which is not conducive to the regulation of Alternaria toxins.Therefore,this study systematically detects and evaluates the levels of five Alternaria toxins(Te A,TEN,AME,ALT,AOH)in commercially available flour,noodles,bread,and steamed buns in the central and northern regions of Anhui Province.The study analyzes the differences in toxin levels among different years,different types of flour products,and different regions.Finally,the study assesses the risk of dietary exposure.The specific research contents include:1.A method for analyzing Alternaria toxins in flour and its products was established.A highly efficient and precise analytical method was successfully established using Qu ECh ERS-UPLC-MS/MS for detecting Alternaria toxins contamination in flour and its products.In four different matrices including flour,steamed buns,noodles,and bread,the recoveries of five toxins at the added concentrations of 2,10,and 100 μg/kg ranged from73% to 110%,with relative standard deviations(RSD)less than 15%.The quantification limits(LOQ)of the five toxins ranged from 0.1 to 1 μg/kg.The results showed that this method has good accuracy and precision,meets the requirements for fungal toxin analysis in agricultural products,and can be used for quantitative analysis of Alternaria toxins in flour and its products.2.The contamination status of Alternaria toxins in flour and its products in the central and northern regions of Anhui Province was identified.A total of 245 samples of flour and its products collected in 2021 and 2022 were analyzed for Alternaria toxins contamination.The results showed that TEN was detected in197 samples,with a detection rate of 80.8%,an average concentration of 0.66 μg/kg,and a concentration range of 0.34 μg/kg to 1.74 μg/kg.Te A was detected in 240 samples,with a detection rate of 99.2%,an average concentration of 4.47 μg/kg,and a concentration range of 1.17 μg/kg to 85.68 μg/kg.AME,AOH,and ALT were below the LOD.The probability of the co-detection of TEN and Te A in all detected samples was 80.4%.Using spearman’s analysis way showed that the correlation coefficients of the two toxins in flour,noodles,and bread were 0.559,0.386,and 0.326,respectively,and their P values were all less than0.05.Therefore,there is a significant correlation between TEN and Te A in flour products.3.An analysis was conducted on the differences in the contamination of Alternaria toxins among different years,flour products,and regions.By comparing the levels of Alternaria toxins in flour products collected from different years,samples,and regions,it was found that there were significant differences in the levels of TEN(ANOVA,F=15.038,P<0.05)and Te A(ANOVA,F=3.936,P<0.05)in flour products in 2021 and 2022.Furthermore,the levels of TEN and Te A in flour were significantly higher than those in noodles,steamed buns,and bread(P<0.05),while the levels of TEN and Te A in steamed buns were significantly lower than those in flour,noodles,and bread(P<0.05).In addition,there were significant differences in the levels of Alternaria toxins in some flour products produced in different regions,such as the significant difference in TEN levels in samples from the northwest and central regions of Anhui Province(P<0.05).4.An assessment of dietary exposure risk to Alternaria toxins in flour and its products was identified.Through the analysis of 245 market samples,the daily exposure doses of Te A in flour products for adult males,adult females,boys,and girls were 31.1,36.2,42.28 and 44.11ng/kg bw/day,respectively,while the daily exposure doses of TEN were 4.6,5.35,6.25,and 6.51 ng/kg bw/day,respectively.These levels were all lower than the daily intake limit of 1500 ng/kg bw/day recommended by the European Food Safety Authority(EFSA),indicating that the dietary exposure levels did not exceed the safety threshold.However,overall,the daily exposure doses of children were higher than those of adults.This thesis focuses on the analysis of five types of Alternaria mycotoxins.Finally,a dietary exposure assessment was conducted for Alternaria mycotoxins,providing theoretical and technical guidance for risk management and ensuring the safety of food and human and animal health in wheat-based products.