Objective The aim of this study was to investigate the microbial contamination situation in infant formula powder during the processes of production.Methods A total of 880 samples were collected from Gansu Province,which included raw materials,manufacturing facilities,personnel swabs and final infant formula powder.The detection method conducted in this study were complied with the standard of the SN/T 0738-1997 and GB 4789,and the microbial species detected in this study included Enterobacteriaceae,Enterobacter sakazakii,and Bacillus cereus.Results The detection rate of Enterobacteriaceae was 28.41％ (250/880),the detection rates of Enterobacter sakazakii and Bacillus cereus were 0.46％ (4/872) and 16.94％ (31/183) respectively.The prevalence of Enterobacteriaceae (40.00％,40/100) was the highest in raw materials.Four Enterobacter sakazakii strains were isolated from the pretreatment workshop,equipment and environment surface.The prevalence of Bacillus cereus was 22.73％ (10/44) in final product.Conclusion The microbial contamination was existent widely in infant formula powder and the production procession.Rigid laws and managements should be conducted to reduce the microbial contamination in raw materials,production processes and the environment,which might improve the quality of infant formula powder.

Classification,toxicity and determination method progress especially the pretreatment and limit of quantitation of beauvericin (BEA) and 4 main kinds of enniatins (ENNs) including enniatins A (ENA),enniatins A1 (ENA1),enniatins B (ENB) and enniatins B1 (ENB1) in food were introduced.The contamination levels of BEA,4 kinds of ENNs and their co-occurrence mycotoxins in food from Spain,Morocco,Italy,Japan and some other countries were analyzed.Establishment of high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) determination method for the complex food matrix was suggested.

Objective To investigate the content of cadmium in shellfish in Guangdong Province and make dietary exposure assessment of cadmium in shellfish.Methods The shellfish samples were collected from Pearl River Delta,Eastern and Western Guangdong Province using random sampling method.Point assessment method was used to evaluate the exposure of dietary cadmium intake from shellfish.The risk of dietary cadmium exposure from shellfish were evaluated.Results Three hundred and seven samples were included in the analysis.The median concentration of cadmium in shellfish was 0.630 mg/kg and the exceeding standard rate was 23.8％ (73/307).The exceeding standard rates in Eastern Guangdong,Western Guangdong and Pearl River Delta were 19.4％ (13/67),23.5％ (16/68),and 25.6％ (44/172),respectively.The corresponding median concentration of cadmium were 0.530,0.806 and 0.853 mg/kg,and the difference was not statistically significant (x2 =0.94,P ＞ 0.05).The average (P50) and high level (P97.5) daily intake of cadmium from shellfish by the total survey population was 0.957 μg/d,and 4.511 μg/d,respectively.The monthly intake of cadmium associated with shellfish calculated from average and P97.5 exposure doses accounted for 1.91％ and 9.02％ of PTMI,respectively.Conclusion The cadmium content of some shellfish in Guangdong Province exceeded the standard.However,the cadmium intake from shellfish by the survey population was not high.

Objective The aim of this study was to analyze of the prevalence of Norovirus in the foodborne disease surveillance population in Baiyin City in 2015,and provide scientific basis for the prediction,early warning,prevention and control of foodborne diseases caused by Norovirus.Methods A questionnaire survey was conducted on the cases of foodborne disease surveillance.Fecal specimen were collected,and Norovirus GⅠ and GⅡ were detected by real time fluorescence quantitative polymerase chain reaction.Results Three hundred and forty-four foodborne disease cases were reported,78 cases were positive,and the detection rate was 22.7％.Five cases were positive for Norovirus GⅠ,and 71 cases for GⅡ.Two cases were positive for both GⅠ and GⅡ.Forty-six cases were male and 32 cases were female.The oldest patient was 83 years old,and the youngest was only 3 months with an average age of 20.3.Conclusion Norovirus was one of the main foodborne pathogens in the city,and the main epidemic was GⅡ in autumn and winter.Public education and health monitoring should be strengthened.

The definition and function of epidemiological investigation report on food safety accident is described and its impact on the business behavior,civil liability,administrative responsibility,and criminal responsibility of food producers,marketers,supervisory and management department is presented.It suggests that center for disease prevention and control should give attention to timeliness,authenticity,accuracy,normalization of epidemiological investigation report on food safety accidents and cases.The purpose is to avoid accountability on investigation of food safety accidents and ensure the epidemiological investigation report not been challenged in legal proceedings as evidence.

This article analyzes the concept,the formation process,the main content of the United States food defense plan,the duties of stakeholders and the key points of the implementation.This article also summarizes the characteristics,similarities and differences between China and the United States in terms of food defense system,discusses the difficulties and put forward some suggestions for the food defense plan in China.

Objective To determine chloramphenicol and metronidazolel in honey by isotope-labelled internal standards ultra performance liquid chromatography-mass spectrometry.Methods Samples were extracted with ethyl acetate solution,and cleaned up on a MCS cartridge.The target analytes were separated on a ZORBAX SB-C18column with gradient elution using a mobile phase made up of methanol and 5 mmol/L ammonium acetate solution (containing 0.05％ formic acid).Detection was carried out using positive and negative electrospray ionization and multiple reaction monitoring (MRM),and quantified with isotope internal standardmethod.Results The chloramphenicol and metronidazolel showed good linearity in the range of 0.05-5.00 ng/ml.The recovery at three spiked levels of 0.5,2.0 and 5.0 μg/kg were in the range of 79.3％-96.7％.The relative standard deviation (RSD) was 5.5％-14.8％.The limits of quantitation were 0.15 μg/kg,the limits of detection were 0.05 μg/kg.Conclusion The method is sensitive and accurate.It could be applied to the high-throughput analysis of chloramphenicol and metronidazolel.

Objective To compare four PCR genotyping method for Clostridium botulinum,and provide the reliable method for detection and identification of Clostridium botulinum from surveillance and foodborn poisoning in Sichuan Province.Methods Six strains of C.botulinum types A,B and E were used to compare four PCR genotyping method-one muhiplex PCR method was from US FDA,two multiplex PCR method and one real-time PCR method were from ISO,and the differences were preliminarily analyzed.Results Three multiplex PCR method could detect C.botulinum types A,B and E in a single reaction.The expected bands for type A were vague using ISO multiplex PCR method 1,whereas bright expected bands could be obtained in the identification of C.botulinum by the other two multiplex PCR method.Real-time multiplex PCR method could detect different types of C.botulinum simultaneously;however,classification should be carried out separately because fluorescent labels were the same.Conclusion Multiplex PCR method from FDA and multiplex PCR method 2 from ISO were relatively simple and could be recommended for C.botulinum surveillance in Sichuan Province.

Objective To establish a method for the determination of perchlorate in food by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).Methods The perchlorate residue in spices and condiments was extracted with water,that in vegetables and fruits was extracted with acetonitrile-water (1∶ 1,V/V),and that in meat,poultry,eggs,milk and aquatic products was extracted with acetonitrile-water (2∶ 1,V/V).The supernatant was cleaned up with C18 SPE (3 ml,200 mg),and the detection was carried out by UPLC-MS/MS with internal standardmethod for quantification.Results The calibration curve was linear in the concentration range of 0.3-20.0 pg/L (R2 ≥0.999),the recovery was in the range of 82.6％-108.6％,the relative standard deviation (RSD) was in the range of 1.0％-9.9％,and the limit of detection was 2.0 μg/kg for milk,and 10.0 μg/kg for other food.Conclusion The method was simple,accurate and highly sensitive,and suitable for the determination of perchlorate in food.

Objective In order to analyze of poisoning causes,a new method was established utilizing hydrophilic liquid chromatography-tandem triple quadrupole mass spectrometer (HILIC-MS/MS) coupled with dispersive solid phase extraction for rapid qualitative and quantitative analysis of tetrodotoxin in nassarius and shellfish.Methods Sample (1.0 g) was extracted with 0.1％ acetic acid in boiling water bath,purified by dispersive solid phase extraction with 50 mg hydrophilic-lipophilic balance (HLB),5 mg graphitized carbon black (GCB) and protein precipitation with acetonitrile,and then filtered through a polytetrafluoroethylene (PTFE) membrane.The analytes were separated on a HILIC column,and detected in selected reaction monitoring (SRM) mode via positive electrospray ionization.The matrix matching and external standard method was used for quantification.Results Tetrodotoxin showed good linearity in the concentration range between 2.0 and 40.0 ng/ml,the correlation coefficient was higher than 0.999.The detection limit of tetrodotoxin in seafood was 10.0 pg/kg.The rates of recovery varied between 74.2％ and 87.9％ with relative standard deviations from 2.3％ to 9.1％ at spiked concentrations of 25,100 and 200 pg/kg.The proposed method was applied in the detection of tetrodotoxin in shellfish and nassarius from coastal cities of Zhejiang Province.Conclusion The method was accurate,fast,easy to operate,which could meet the requirements of public health emergency testing or routine testing.