Abstract:Objective To study mutiresidual level of persistent organochlorine pesticides in animal origin foods，to provide information on the evaluation of the effectiveness of Stockholm Convention in the reduction or elimination of the release of POPs into the environment in China. Methods Pork, beef, mutton, chicken, fishes, egg and milk were collected at random from markets in13 different cities. The methodology used for the analysis of OCPs was based on acetone -petroleum ether extraction, gel permeation chromatography (GPC) cleanup, and gas chromatography with electron capture detector according to GB/T 5009.19—2008. Nines organochlorine pesticides (20 compounds) including hexachlorocyclohexanes (HCH), dichlorodiphenyl trichloroethane (DDT), aldrin, chlordane, dieldrin, endrin, heptachlor, hexachlorobenzene (HCB) and mirex were determined. Results The residual level of nines persistent organochlorine pesticides in animal origin foods were low level. Only β-HCH、pp′-DDE、HCB and heptachlor were detected over 3 times of the limit of detection (LOD) and other compounds were all near LOD. Conclusion The residual level of persistent organochlorine pesticides in animal origin foods dramatically decreased with the various bans and restrictions on HCHs, DDTs and other organochlorine persistent pesticides usage in China.

Abstract:Objective To establish a GC-MS method for the detection of 1,3-dichloro-2-propanol（1, 3-DCP）and 2, 3-dichloro-1-propanol（2, 3-DCP）in soy sauce by using a head-space solid phase micro-extraction device. Method Extracting 1, 3-DCP and 2, 3-DCP from soy sauce in 50 ?C water bath for 30 min with a Carboxen^TM/Polydimethylsiloxane（CAR/PDMS，75μm）fiber. The fiber was then transferred to the injection port of GC – MS to allow the analyte absorbed and separated by DB – WAX capillary column (30 m×0.25 mm×0.25 μm) and detected by mass spectrometry. Using d₅-1,3-DCP as internal standard for quantification. Results The linear range for 1, 3-DCP and 2, 3-DCP was 5-160 μg/kg, and the detection limits were 2.0 μg/kg and 0.5 μg/kg respectively. The recoveries of standard addition at 5μg/kg, 20μg/kg and 50μg/kg were in the range of 82.9 % - 103.0 %, and the relative standard deviations (RSD, n=7) were in the range of 2.5 % - 10.6 %. Satisfactory results were obtained in the detection of 1, 3-DCP and 2, 3-DCP in soy sauce samples. Conclusion The method is simple, fast, accurate, sensitive, and suitable for the determination of 1, 3-DCP and 2, 3-DCP in soy sauce.

Abstract:Objective To develop a rapid and simple method of loop-mediated isothermal amplification (LAMP) for detecting Escherichia coli O157∶H7 in foods. Methods Based on the characteristic conserved sequence of lipopolysaccharide gene (rfbE, GenBank S83460) of O157 antigen and flagellin gene (fliC, GenBank L07388) of H7 antigen, the 1oop-mediated isothermal amplification method was developed to detect the specificity of twenty-one E Coli O157∶H7 strains and non E Coli O157∶H7 strains. The results of LAMP were compared with PCR. The feasibility of LAMP was evaluated by detecting Escherichia coli O157:H7 in food samples. Results The detection could be finished by LAMP within 1 hour; the sensitivity was 96.72%, the specificity was 85.71% and the accuracy was 93.26%. The sensitivity of LAMP was higher than that of PCR. Conclusion LAMP is a simple, rapid method suitable for screening Escherichia coli O157:H7 in suspicious samples.

Abstract:Objective To revise CB/T 5009. 62-2003 and provide technical support for the revision of GB13121- 1991 Hygienic .standardfor ceramicfood containers. Method It is suggested to keep flame atomic absorption spectrometry ( FAAS) in, remove dithizone colorimetry (DSMP) from, add inductively coupled plasma mass spectroruetry (ICP-MS) and graphite furnace atomic absorption spectrometry ( GFAAS) to the latest edition of GB/T 5009. 62. The de.tecting conditions and technical parameters for ICP-MS and CJFAAS were optimized through researches on methodology and inter- laboratory comparison. Results The migration of lead and cadmium from ceramic food containers were detected by ICP-MS and GFAAS. The limit of quantitation ( LOQ) of lead was l. 0 μg/L ( as ICP-MS) and 2. 5μgL ( as GFAAS) , and the LOQ of cadmium was 0. IμgL ( both ICP-MS and GFAAS). The recovery rate of adding standards of lead rates were 89. 0% -1140-/o ( as ICP-MS) and 88. 2c/o -110% ( as GFAAS) , and the recovery rates of adding standards of cadmium were 86. 2% -94. 0% ( as ICP-MS) and 90. 0% -108% ( as CFAAS) in the inter-laboratory. The migration of lead and cadruium from 60 ceramic food container samples produced from different origins were tested by ICP-MS and (;FAAS, no statistically significant differences between these two methods were observed by paired t-test. Conclusion ICP-MS and CFAAS are the most advanced analytical technology with high sensitivity and acc:uracy in detecting trace amount of lead and cadmium. The migration of many trace metals released from ceramic surface could be detected at the same time by ICP-MS. As the GB/T 13121 is going to be revised, more stringent limits for the migration of lead and cadmium from products made by different technologies might be stipulated. Introducing ICP-MS and GFAAS to GB/T 5009. 62 is necessary.

Abstract:Objective To solve the problem on the lower content of triglyceride ester type unsaturated fatty acids in fish oil products detected by the rapid transesterification method in the current national standard. Methods The method was improved: after dissolving samples into n-hexane, the fatty acid was then methylated with potassium hydroxide–methanol transesterification; the transesterified solution was washing to neutral with water and then detected by gas chromatography. Results The results of four main unsaturated fatty acids (?-linolenic acid, EPA, DPA and DHA) were in the satisfactory range. Conclusion The improved method was simple, accurate and reliable for the determination of triglyceride ester type unsaturated fatty acids in fish oil products.

Abstract:Objective To understand the trends and epidemiological characteristics of bacterial foodborne disease outbreaks. Method Based on the data from the national monitoring network on foodborne disease reported in 2003-2007, analysing the incidence, hospitalization rate and mortality caused by bacterial foodborne disease events, and their epidemiological characteristics on time trends, regional differences, demographic characteristics, also the food attribution, main pathogens and main causes. Results The outbreaks of bacterial foodborne diseases reported to the national monitoring network in 2003-2007 were 1060 events, involving 32 261 cases, 16 426 hospitalizations and 16 deaths. Summer and autumn were the high incidence seasons for foodborne diseases. The 6-15 year groups were the focus population. Vibrio parahaemolyticus was the most important pathogen, livestock and poultry meat were the main causing food, and self-made grains were the leading cause of death for foodborne diseases in China. Incorrect procession of food was the most important cause of outbreaks. Conclusion The outbreak caused by bacterial foodborne diseases is still a important issue on public health in China. Foodborne disease monitoring network remains to be further improved.

Abstract:Objective To study the chronic toxicity and carcinogenicity of 95% isocarbophos and to provide its no observed adverse effect level (NOAEL). Methods Four hundred and eighty male and female SD rats were divided into 4 groups and fed with foods containing 0, 0.6, 6 and 30mg/kg isocarbophos respectively for 2-years. The daily behavior, body weight, food consumption, blood biochemistry, clotting time, cholinesterase activity, gross anatomy and histopathology, and the incidence of tumors were examined and analyzed. Results Activities of cholinesterase were significant decreased in some females (at the 6, 18, 24 month of the 30mg/kg group) and males (at the 6, 12, 18, 24 month of the 6 mg/kg and 30mg/kg groups). There were no any significant changes at any level of Isocarbophos on any other parameters including the incidence of tumor in any organ or tissue. Conclusion The NOAEL of isocarbophos were 0.486 and 0.037 mg/(kg BW?d) for female and male respectively, and isocarbophos is non-carcinogenic under the conditions of the study.

Abstract:Objective To establish an in vitro screening method for hepatotoxicity and nephrotoxicity and to apply the test in screening the toxicity of raw materials for health food. Methods Primary hepatocytes, primary nephrocytes, CHL and HepG2 cells were cultured. IC₅₀ values were tested by MTT, and the enzymes leakaging from cells were measured by biochemical methods and used as markers for toxicity. The method was validated by known toxic substances and was applied in screening the toxicity of raw materials for health food, such as water-extracted Rhubarb, Rhizoma Atractylodis and Safflower. Results The method was effective for screening the hepatotoxicity and nephrotoxicity. Target toxicity was not found from Rhubarb and Rhizoma Atractylodis on hepatocytes and nephrocytes. It might have potential nephrotoxicity from Safflower water-extracts. Conclusion The in vitro screening test for hepatotoxicity and nephrotoxicity was able to be used in screening raw materials for health food. Further study on evaluating the safety of Safflower water-extracts might be needed.

Abstract:Objective To establish a method for molecular typing Pseudomonas cocovenenans subsp. farinofermentans with pulsed-field gel electrophoreses (PFGE), and to analyze the type of 29 isolates with PFGE method. Method The isolates were digested with 5 kinds of restriction endonucleases XbaⅠ, SpeⅠ, NotⅠ, SmaⅠ and AscⅠ, and the PFGE patterns were analyzed by BioNumerics software. Results The bands on PFGE for the fragments digested by restriction endonucleases NotⅠ, SmaⅠ or AscⅠwere too small, and that digested by XbaⅠ were too many to identify clearly. The restriction endonucleases NotⅠ, SmaⅠ, Asc and XbaⅠwere not suitable for typing the pathogen on PFGE. The number of bands on PFGE for the fragments digested by SpeⅠ was moderate and the pattern of molecular weight was clear and well discriminated. Conclusion This method can be used for molecular typing and tracing Pseudomonas cocovenenans subsp. farinofermentans.

Abstract:Objective To study the distribution characteristics of virulence genes in Vibrio parahaemolyticus isolated from seafood in China. Methods Using polymerase chain reaction to detect the virulence genes tdh and trh, and to detect the species-specific genes tlh and toxR in 192 experiment strains. Results There was no strain carrying tdh gene, and 4 stains carrying trh gene, accounted for 2.08% of strains in 192 food isolates. The strains carrying tlh and toxR genes were 100%. Conclusion The rate of carrying virulence gene in Vibrio parahaemolyticus from seafood isolates was very low in China.

Abstract:Objective To evaluate the risks associated with pork contaminated by Staphylococcus aureus, so as to provide references for improving the microbial risk assessment and adopting effective risk management measures. Method Multiple growth model was used to predict the growth of Staphylococcus aureus in pork stored under room temperature for not more than 24 hours during the time period from June to October. Results The probabilities of occurring Staphylococcus food poisoning related to pork consumption from June to October were 3.3%, 33.6%, 21.4%, 7.6% and 0.3%. In June, September and October, the most related factor for Staphylococcal food poisoning was the contamination of Staphylococcus aureus at the time of purchasing. While in July and August, Staphylococcal food poisoning was most likely induced by long term storage of foods. Conclusion The risk of occurring Staphylococcal food poisoning caused by the consumption of pork was the highest in July, and then in August, September, June and October. The probability of Staphylococcal food poisoning in the five months was in consistent with the distribution of temperature, the higher the temperature the more susceptible to Staphylococcus food poisoning. It is suggested that the prediction model used in our study is valid.

Abstract:Objective To analyze the change of content and ratio of isoflavone aglycones in soybeans treated by drying in oven at 50 ℃, 100 ℃ and 150 ℃，microwave heating for 5 minutes and frying to be ripen. Methods Extracting samples in 80 % ethanol with ultrasonic wave. Soybean isoflavones were separated on an Agilent SB-C18 column and gradient eluted with a mobile phase of methanol plus 0.2 % ice acetic acid. Aglycones and β-glycosides were determined by high performance liquid chromatography with ultraviolet-visible detector at 260 nm. Results Two kinds of aglycone (daidzein and genistein) and two kinds of β-glycoside were detected. The content of daidzein increased 1- to 5-folds, and genistein increased 3- to 15-folds when the temperature in oven was increased from 50 ℃ to 150 ℃. The increase of β-glycosides and aglycones in fried soybeans was the most. The result of heating in microwave was the same as drying in oven at 50 ℃. The results for green bean and black bean were similar to soybean. Conclusion Parts of isoflavone glycoside in soybean were transformed into aglycone by heating, and the active components were then increased and more valuable for human nutrition and health.

Abstract:Objective To evaluate the lead-eliminating effectiveness of a lead-excreting food on lead poisoning in mice. Methods Ninety Kunming male mice with body weight of 18?22g were randomly divided into six groups: negative control group, lead poisoning model group, positive control (lead-eliminating medicine) group, and low, medium and high dose lead-excreting food treated groups. Except the negative control group freely drinking deionized water, other groups were drinking water contained 1.00g / L of lead acetate freely for 30 days for lead exposure. The mice in treated groups were given the lead-excreting food by gavage, based on 5-, 10- and 20-fold of the recommended dosage for human consumption (0.60 g / (kgBW?d)). The mice in the positive control group were given dimercaptosuccinic acid (DMSA) solution, and the mice in model control group and negative control group were given deionized water by gavage. The lead content of whole blood, liver, femur, kidney and brain was determined a month later. Results The lead content in blood, liver, kidney and brain of the three lead-excreting food treated groups was significantly lower than that of the lead poisoning model group (P ＜0.05 or P ＜0.01); the lead content in the femur of high and medium dose lead-excreting food groups was significantly lower than the lead poisoning model group (P ＜0.01); Conclusion The lead-excreting food is effective in eliminating lead from mice.

Abstract:Objective To establish an ethanol-induced oxidative stress mice model and evaluate the antioxidant capacity of curcumin; and to explore an evaluation method for bioactive antioxidants. Methods Sixty Kunming mice on the age of 8 weeks were accommodated for 1 week and then divided into 5 groups. The test substance curcumin was given at the dosage of 10mg and 30mg per 10 grams of body weight by gavages for 5 weeks. The activity of GPx and SOD in plasma and GPx, SOD, MDA and PCO (protein carboxyl content) in liver were tested by the end of the experiment. Results The activity of GPx both in plasma and in liver was lower than the control group (P <0.05) and the protein carboxyl content (PCO) in liver was higher than the control group (P <0.05). Conclusion Oxidative stress model could be established in mice induced by lower concentration of ethanol for a long time; and the antioxidant capacity of curcumin was identified in the model. PCO could be used as an effective biomarker for the evaluation of oxidative stress.

Abstract:Objective To investigate the proficiency of testing lead in food safety lahs in China and to enhance the technical level and quality control capability of lahs participating in the test. Method Lahs were invited to participate in the Proficiency Testing ( PT) voluntarily. Using routine methods in their lahs to detect lead in food additive calcium powder was recommended. Testing results were analyzecl by Robust Stat. Results There were 83 labs participating in the PT, 76 labs reported their results, 78.9% of results were satisfied, 14. 5% were uncertain and 6. 6% were unsatisfied. Conclusion Most of food safety labs participating in the test could accurately detect lead in food additive calcium powder samples.

Abstract:Objective To find out the proficiency of provincial-level food inspection agencies on food testing; and to improve the accuracy, reliability and comparability of testing results. Method Criteria for evaluating the testing results were based on the Z scores: Z ≤2 for satisfactory results; 2＜ Z ＜3 for uncertain results and Z ≥3 for unsatisfactory results. Results The samples for quality control were delivered to 31 provincial-level food inspection agencies, 29 of them submitted results back on time (93.55%). The satisfactory, uncertain and unsatisfactory results for sulfur dioxide test were 87.10%, 3.23% and 9.68%; and that for tartrazine were 80.65%, 9.68% and 9.68% respectively. The satisfactory results for ponceau 4R, sunset yellow and amaranth were all 93.55%. Conclusion Through inter-laboratory comparison, provincial-level food inspection agencies recognized the problems in the process of testing, found out the cause of uncertain and unsatisfactory results, and conducted effective corrections to ensure the accuracy of the data issued in their reports.

Abstract:Objective To improve the regulations of using processing aids in food industries; and to strengthen the management of using processing aids. Method Carrying out investigations on processing aids (excluding enzymes) used in food industries, including the name, function, scope of application, level in use and residues etc. Results The problems on processing aids used in China were not clarifying in definitions, imperfection on principles of incorporation, lack of clear scope of application and the maximum level for use (or the allowed level for residues) etc. Conclusion Regulations for processing aids in China need to be further improved in combining the surveyed results of using processing aids in food industry with referring the regulations used in other countries.

Abstract:Objective To understand the contamination of ochratoxin (OTA) from beer in Beijing and estimate the exposure of OTA in local residents. Methods OTA in beer samples were detected by IAC-HPLC-FD and were evaluated by referencing to the EU dietary exposure assessment methods. Results OTA was found in 39 of 87 beer samples, with a positive rate of 44.83%. The average concentration of OTA was 0.015ng/ml in the range of 0.010 -0.093ng/ml; the average concentration of positive samples was 0.026ng/ml. The intake of OTA per week from beer in Beijing residents was 0.01-0.50ng/kg. Conclusion The contamination of OTA from beer in Beijing was low in comparing with other countries. The exposure to OTA from beer in local residents was lower than 100ng/kg bw of PTWI proposed by JECFA and lower than 5ng/kg BW of TDI proposed by EU.

Abstract:Objective To investigate the contamination of Listeria in some foods from farm markets and to detect the virulence genes of Listeria monocytogenes in Minhang district of Shanghai. Methods Based on the national standard methods, Listeria in food was separated and biochemically identified by using CHROM agar color medium and API reagent strips. The virulence gene of hly, prfA, plcB, iap, inlA and actA were detect by PCR methods． Results There were 36 strains of Listeria isolated and identified from 320 samples, including 10 strains of Listeria monocytogenes, 23 strains of Listeria innocua and 3 strains of other Listeria． Excepting the absence of actA, virulence genes hly，prfA，plcB，iap，inlA were identified in all 10 strains of Listeria monocytogenes. Conclusion The contamination of Listeria is existed in foods from farm market in Minhang district of Shanghai. Supervision and management should be strengthened on raw meat and poultry, which were serious contaminated. The absence of virulence gene actA in all Listeria monocytogenes isolated from local food needs further study.

Abstract:Objective To survey the status quo of food-borne diarrhea in Jing’an district and to provide basic information for food-borne disease surveillance network, so as to put forward the corresponding countermeasures. Method Conducting a household survey on 201 residents selected by cluster sampling method. The subjects were investigated by questionnaires on the general conditions, their knowledge and behavior on food safety, the incidence of foodborne diarrhea, and the evaluation and needs on food hygiene and safety. The database was built with Epidata and analyzed with statistic software SAS. Results The prevalence rate of diarrhea in the year was 25.87% and the rate of diarrhea in two weeks was 4.98% and the prevalence rate of foodborne diarrhea in the year was 5.97% and the rate of foodborne diarrhea in two weeks was 1.49%. The prevalence rate of diarrhea was not affected by gender, age, occupation, education, marital status and health status significantly, but the prevalence rate of food-borne disease varied significantly with the income (P<0.01) and the ways of preparing foods (P <0.05). The risks were 6.41 times higher in residents not using knife separately for preparing raw and cooked foods and the risks were 5.23 times higher in residents not using chopping block separately than those using knife and chopping block separately for preparing raw and cooked foods. The prevalence of diarrhea was affected by the manner of disposing bad smelled or deteriorated foods. The risks for eating deteriorated food after cooking again were 10.05 times higher than not eating. The risks for residents without refrigerator at home were 5.03 times higher than those with refrigerator at home. Conclusion A proportionate of foodborne diseases still occurred in Jing’an district. The hygienic awareness in the process of food in kitchen should be strengthened; and personal hygiene and good dietary habit should be developed. The knowledge on food safety should be promoted widely.

Abstract:Objective To understand the contamination of cadmium in some food in Siming district. Methods Food samples were randomly collected from supermarkets and open fairs and tested by graphite furnace atomic absorption spectrometry according to GB/T 5009.15—2003 Determination of Cadmium in Foods. Results The rates exceeding the limit for cadmium in aquatic products and edible fungus were 31.8% and 82.4% in tested samples respectively. Conclusion The contamination of cadmium in some foods was serious in Siming district. It is suggested that enhancing a comprehensive treatment of the environment on breeding industry, paying more attention to the quality management of input materials in the breeding industries and the culture medium for fungi; establishing unified standards on food quality and safety and strengthening construction of a food security monitoring system.

Abstract:Organophosphorus pesticides (OPPs) are widely used in agriculture, causing risks for environment as well as for human health. The development trends of extracting and purifying samples and the detection methods for residues of organophosphorus pesticides in biological materials and the food of animal origin were reviewed.