| Abstract Objectives To establish and perfect national standard methods to detect 4 kinds of mycotoxins(ochratoxin A,zearalenone,deoxynivalenol and T-2 toxin)and dehydroacetic acid,to establish acrylamide in food products, to analyze the content of acrylamide in commercial food products and the impact of processing conditions on the amount of acrlamide, and to observe the effects of acrylamide on growth and anti-oxidant fuction of rats. Methods 1. Establishment of methods to analyze toxic materials in food products. (1) Analysis of acrylamide in food products. Acrylamide was detected by liquid chromatography after extracted by solid-phase extaction column purification, or detceted by gas chromatographyμ-ECD determination after derivatived intoα,β-dibromo-propanamide. (2) Methods to detect ochratoxin A, zearalenone, deoxynivalenol and T-2 toxin. After extracting the 4 kinds of mycotoxins from the samples, filtrating and diluting, the dilution passed an immunoaffinity column bonding with mycotoxin-specific antibody. Then the mycotoxins were bonded by the antibodies. The mycotoxins were washed off after washing the impurities, and were finally detected by UV detector or fluorescence detector of a high-performance liquid chromatography quantitatively. (3) Methods to detect dehydroacetic acid in food products. Dehydroacetic acid was extracted from samples by using sodium hydroxide, and then detected by UV detector of a high-performance liquid chromatography quantitatively.2. Analysis of acrylamide in food products, its toxicity and formation mechanism. (1) 212 kinds of commercial food products from 12 categories were detected for the acryamide content. Affection of 7 kinds of processing conditions on the cocentration of acrylamide. (2)The method to detcet acrylamide and its metabolites in tissues was established, as well as the method to detect 8-hydroxy-deoxyguanosine (8-OHdG) in rat urine. (3) Affection of acrylamide on the anti-oxidant activity of rats. Rats were fed with different dosage of acrymalide for 2 weeks, and then the activity of superoxide dismutase (SOD) and glutathione peroxydase (GSH-Px), and the content of malondialdephyde (MDA) in blood and liver tusse were detceted by using kits. And the 8-hydroxy-deoxyguanosine (8-OHdG) content in urine were analyzed by LC-MS/MS. Results 1.4 kinds of mycotoxins detection methods were established and all were easy-operating and accurate with high recovery rate, and the reproducibility was very good with good precision. The limited quantity (LOQ) of ochratoxin A was 0.5μg/kg, the recovery was 90.3%-106.0%, The relative standard deviation(RSD) was 1.75%; The LOQ of zearalenone was 20μg/kg, the recovery was 98.2%-100.5%, RSD was 1.0%; The LOQ of deoxynivalenol was 0.1mg/kg, recovery was 72.0%-85.9%, the maximum RSD was 4.9%; The LOQ of T-2 toxin was 2.0μg/kg, recovery was 93.9%-103.1%, RSD was 3.4%; The LOQ of dehydroacetic acid was 0.5mg/kg, recovery was 96.5%-99.5%, the RSD was 1.09%; The two kinds of analytical methods of acrylamide had a good consistency,The LOQ by GC-μ-ECD was 0.02mg/kg, recovery was 84.6%-98.5%, The LOQ by HPLC was 0.05mg/kg, recovery was 86.3%-96.9%.2. The acrylamide contents of 212 kinds of commercial food products from 12 categories of Qingdao were 0-1240μg/kg.3. All the 7 kinds of processing conditions and raw materials affected the formation of acrylamide with different degrees. Temperature, heating time, pH, amino acid and reducing sugar species, as well as the types of additives have a significant effect on acrylamide formation.4. Compared with the control group, SOD activity of the liver homogenate and serum in groups of acrylamide exposure decreased (P<0.05,or P<0.01). GSH-Px activity of serum also increased, but increased in liver homogenate. MDA content increased(P<0.05),8-OhdG content increased (P＜0.05).Conclusion 1 The five methods of detecting ochratoxin A, zearalenone, deoxynivalenol, T-2 toxin and dehydroacetic acid have been accepted as national standards.2 The acrylamide contents of 212 kinds of commercial food products were different, Temperature, heating time, pH, amino acid and reducing sugar species, as well as the types of additives have a significant effect on acrylamide formation.3.Acrylamide reduces the activity of antioxidant enzymes in rats, increasing lipid peroxidation, and can lead to oxidative damage of DNA. |
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