Abstract:Food for special dietary uses had obtained extensive attention now, so the development of standard system and identification of category is of great importance. In this paper, the definition and main types of food for special dietary uses in China, as well as international and other countries were introduced, and suggestions for the future work were proposed.

Abstract:To investigate the subspecies, phenotypic and genetic characterization of Cronobacter isdates from infant food in 2010.Methods All isolates were reactivated, then suspectable stains were identified preliminarily by two methods, PCR amplifying ompA gene and API 20E. To confirm these stains, full 16S rRNA gene sequences were obtained, and made BLASTN on GeneBank database. The identified strains were streaked onto DFI chromogenic agar and TSA to observe phenotype and yellow pigment production. Biochemical tests were conducted and assigned to biogroups to determine their species.Results Nine strains were identified as Cronobacter spp. These strains were assigned to 5 biogroups, and belonged to 4 species. The majority of strains were Cronobacter sakazakii, and three strains was identified as C.malonaticus, C.muytjensii and C.dublinensis respectively. 7 strains were identified as Cronobacter by API 20E, yet ompA gene amplification of all strains was positive.Conclusion Cronobacter isolated from infant food were diversed in biochemical phenotype and species. There was a risk of Cronobacter in infant food from supermarkets. There was limitation to identify the bacteria only by biochemical phenotype, and supplementary molecular biology methods was necessary.

Abstract:To evaluate the protein nutritional value fed milk powder containing recombinant human lactoferrin derived from transgenic cloned cattle.Methods Based on gender and weight, 100 weanling SD rats were randomly divided into five groups, casein normal control group, recombinant human lactoferrin milk powder group, normal milk powder control group, recombinant human lactoferrin reference group, cattle lactoferrin reference group. They were fed for 28 d. Bodyweight and food consumption were observed,hematology and clinical biochemistry were measured during the experiment period.The rats were sacrificed at the end point for organ weight measurement and pathological examination. The protein efficiency ration and amino acid score were calculated. Results The protein efficiency ratio of rhLF milk power had no significant statistical discrepancy than other control groups in male rats. The result of the female rats was the same. The data of amino acid score of rhLF milk power and normal control group are slightly different.Conclusion The protein efficiency ratio of rhLF milk power equalaled the other milk powder groups. The protein amino acid score of rhLF milk powder showed PHE and TYR were the first limited amino acid.

Abstract:To explore the antibacterial activity of lemon peel and pulp fresh juice against seven common foodborne pathogens and its effects on bacteria biofilm formation.Methods The fresh lemon peel and pulp juice were prepared by juice extractor. The total acids of fresh lemon peel and pulp juice were determined. Volatile compounds of lemon peel and pulp fresh juice were extracted by headspace sampling and the extracts were detected by gas chromatography-mass spectroscopy (GC-MS). The antibacterial tests of lemon peel and pulp fresh juice were examined on tryptic soy agar (TSA). The bacteria biofilm formations were tested by tube method and 96-well method. Results The total acids were 98.86 g/kg for pulp fresh juice, and 6.05 g/kg for peel fresh juice, respectively. GC-MS analysis showed limonene, γ-terpinene, α-terpineol and citral were the main volatile compounds in lemon peel and pulp fresh juice. The growths of seven target pathogens on TSA were inhibited distinctly by lemon pulp juice and did not affect by lemon peel juice. The tube and 96-well methods for the bacterial biofilm formation tests showed that the lemon pulp juice had obvious inhibition to several bacteria biofilm formation, and lemon peel juice had obvious promoting effects to most bacteria biofilm formation.Conclusion The effects of lemon juice on common foodborne pathogens and their biofilm formation provide meaningful scientific data for the prevention and control of foodborne pathogens.

Abstract:This study aims to investigate the effects of limonin on learning and memory abilities and antioxidant capacity of natural apolexis rats.Methods 18 months male SD rats was used as natural apolexis model, and randomly divided into control group and limonin group (50,0 mg/kg), and then continuous lavage for 6 weeks. At seventh week of the experiment, the learning and memory ability were determined by Morris water maze, and the oxidation and anti-oxidation ability was detected in rat serum and brain tissue. Results Different doses of limonin could reduce the time of reaching the end and the total distance of swimming, the times through original security platform, the original security platform in quadrant activity time and distance in space exploration test were significantly increased, and limonin could reduce MDA and Lipo levels in natural apolexis rats serum and brain tissue, increase the SOD, GSH-Px activities in serum and brain tissue and the ability of T-AOC in brain tissue.Conclusion Limonin could improve the learning and memory ability of natural apolexis rats, improve the antioxidant ability of brain tissue, delay the aging of the brain function.

Abstract:To conduct the molecular subtyping and antibiotic resistance analysis of Salmonella Stanley isolated from a foodborne disease outbreak in Beijing and to identify the cause and implement effective prevention and control measures.Methods 15 strains were tested for antibiotic susceptibility and their DAN were digested by Xba I, compared with other strains in the database.Results All of the 15 strains isolated from foods and patients showed the same serological subtype, similar antibiotic resistance results and 100% homologous PFGE patterns which couldn't match to the PFGE database.Conclusion The multi-county foodborne disease outbreak was caused by Salmonella Stanley which were resistanted to ERY and sensitive to 16 antibiotics.

Abstract:To investigate the molecular epidemiological relationship of Salmonella enteritidis strains isolated from 2 food poisoning events occurred successively in the same location.Methods Pathogen isolation and culture was conducted according to GB 4789.4-2010. The phenotype of isolates were identified. VITEK-Ⅱ compact automatic bacteria identification system was used for the antibiotic resistance analysis. Pulsed field gel electrophoresis (PFGE) was used for the molecular subtyping and epidemiological characteristics analysis. Results 23 strains of Salmonella were isolated, among which 17 strains were isolated from anal swab specimens of 25 patients, 2 strains from 8 employees, 3 strains from reserved sample of food and 1 strain from kitchenware. Serum antigen type were (9∶m∶-). The result of the biological characteristic and antibiotic resistance analysis were basically the same. PFGE pattern were the same.Conclusion Epidemiological investigation, pathogen detection and molecular typing indicated that these two cases of foodborne outbreaks were caused by the same source of Salmonella enteritidis contamination.

Abstract:To investigate the pathogen of a food poisoning accident and provide scientific evidence to identify the cause.Methods Isolation, identification and toxicological assessment of toxic agents were carried out according to the national standard GB/T 4789.29-2003, bongkrekic acid was detected by liquid-plasma chromatography techniques according to GB/T 11675-2003. Results By VITEK 2 COMPACTR and Ribo-Printer microbial characterization system, Burkholderia gladioli was identified in 3 of 4 food samples, but all of the 4 food samples were confirmed to be contaminated by Pseudomonas cocovenenans subsp.Farino. A positive toxicological result was found in mice acute oral toxicity test.Conclusion The food poisoning accident was associated with ingestion of foods contaminated by Pseudomonas cocovenenans subsp.Farino.

Abstract:To compare the toxic effect and pulsed field gel electrophoresis (PFGE) of 11 Clostridium sporogenes isolates recovered from whey protein concentrate (WPC) suspected to be contaminated with Clostridium botulinum, powdered infant formula (PIF) made from WPC and PIF not related to WPC collected in New Zealand and China.Methods Broth cultures of all C.sporogenes isolates were centrifuged and filtered. The supernatants were orally administered and intraperitoneally injected to ICR mice, respectively. The clinical manifestations of mice were recorded. All isolates were subjected to PFGE analysis and the PFGE patterns were interpreted.Results Mice receiving intraperitoneal injection of the culture supernatant of all 11 C.sporogenesisolates were dead. The most important poisoning symptoms included irritable, hair arched, shortness of breath followed by sudden death within 10 min. No poisoning and deaths occurred in mice with oral administration of the cultures. PFGE analysis revealed that 7 isolates from China and 3 isolates from New Zealand isolated from WPC and its products share the same PFGE profiles. Different PFGE profile was found in 1 isolate from PIF not related to WPC.Conclusion No difference in toxic effect of the culture supernatant produced by 10 C.sporogenes isolated from WPC and its products which collected in China and New Zealand was observed. The results suggested that WPC contaminated with C.sporogenes detected in both China and New Zealand may be from the same sources, owing to the same PFGE profiles in C.sporogenes from both countries were found.

Abstract:To investigate the difference of biochemical indicators between decapitated blood, abdominal aortic blood and abdominal venous blood on in Wistar rat, and to provide the basis and reference of blood sampling method for toxicology tests.Methods 40 male and 40 female Wistar rat were divided into decapitated blood group and abdominal aortic/venous blood group. Serum parameters of TP, ALB, A/G, ALT, AST, BUN, CRE, CHO, TG, GLU were detected by automatic biochemical analyzer.Results All parameters were differences between these two blood sampling methods in two kinds of gender. The broken blood group in TP, ALB, A/G(female P<0.05), ALT, AST, CRE(female P<0.05), CHO, TG exceed the abdominal aortic blood group obviously on two sex(P<0.05), lower glucose in the broken blood group(P<0.05), BUN in the broken blood group exceed abdominal aortic blood group on female (P<0.05). Influences of aortic blood and venous blood embedded in serum parameters of TG, GLU, TG in the abdominal aortic blood group was lower on two sex(P<0.05), GLU in the abdominal aortic blood group exceed the abdominal venous blood group obviously on male(P<0.05), no difference in female.Conclusion There are significant influences on biochemistry parameters between different blood sampling methods and arterial blood and venous blood in Wistar rat.

Abstract:To explore the identification of the meat and meat products based on Cytb gene.Methods A total of 21 samples were collected randomly. DNAs were extracted by CTAB method. Conventional PCR technique was applied to amplify Cytb genes and the amplified PCR products were sequenced. DNAMAN software was used to align the Cytb sequences. Results CTAB method was suitable for DNA extraction in meat products. The DNA sequencing and alignment results indicated that 9 beef samples were consistent with the label, and one was pork; one mutton sample was consistent with label, another was detected as pork; one pork sample was consistent with label, and the other was detected as chicken; one chicken sample was consistent with label; 2 yak samples were consistent with label, and four were detected as water buffalo meats.Conclusion Sequences alignment method based on Cytb gene was suitable for the market meat products identification. Moreover, meat adulteration was very serious.

Abstract:To develop a rapid, accurate and sensitive method for the simultaneous determination of five industrial dyes (acid red 2G, acid red 14, acid yellow 73, orange 2 and acid blue 62) by solid phase extraction (SPE) and high performance liquid chromatography.Methods Samples were extracted by ammonia-methanol-water (2∶18,V/V), and cleaned up by the HLB solid phase extraction column. The analytes were washed with 0.1% formic acid, eluted with 5% ammonia-methanol and dried by nitrogen. The residue was dissolved with the initial mobile phase, and the solution was separated on a ZORBAX SB-C₁₈(4.6 mm×250 mm, 5μm)column by using acetonitrile-ammonium acetate solution as the mobile phase in gradient program. Detection was performed with UV detector of variable wave-length. Quantitative analysis was carried out by measuring peak area and comparing it with external standard. Results There was good linearity in the range of 0.50-50 mg/L for the five dyes. Recoveries were in the range of 86.0%-110.2%, and the relative standard deviation (RSDs) were lower than 6%. The limits of quantification (LOQs) were in the range of 0.5 mg/kg. Conclusion This method is simple, sensitive and reproducible, which could be applied to the routine analysis.

Abstract:A method was developed for the simultaneous determination of four eugenol derivatives residues(eugenol, isoeugenol, methyl eugenol, methyl isoeugenol) in aquatic products by solid-phase extraction-high performance liquid chromatography with fluorescence detection.Methods The samples were extracted by acetonitrile. The extracted solutions were cleaned up by neutral alumina coupled with C₁₈ solid-phase extraction column. The target compounds were separated on a reversed phase C₁₈ column using methanol-acetonitrile and 1% acetic acid as mobile phase, detected by the fluorescence detector at an excitation wavelength of 280 nm and an emission wavelength of 320 nm. External standard method was applied for quantitative analysis. Results The calibration curves of four eugenol derivatives showed good linearity within their respective linear ranges and high correlation coefficients (r>0.999). The limits of detection and the limits of qualification were 3.0-6.0 and 10.0-20.0 μg/kg, respectively.The average recoveries were in the range of 74.7%-103.0% with the relative standard deviations (RSDs) of 2.6%-8.1%. Conclusion The method was simple, highly sensitive and practical. It was suitable for the determination of eugenol, isoeugenol, methyl eugenol and methyl isoeugenol residues in aquatic products.

Abstract:To improve the efficiency of digestion of the sample and explore the possibility to replace the traditional acid-driven with efficient vacuum acid-driven method for heavy metal detection.Methods 3 samples of 7 typical categories were detected by graphite furnace atomic absorption method for lead, cadmium, copper, chromium and nickel, traditional acid-driven and vacuum acid-driven method were applied. Results There was no significant difference between two acid-driven methods, and the RSD of vacuum acid-driven method was 0.04%-0.95%. Conclusion Compared with traditional method, the vacuum acid-driven method could effectively reduce the digestion time as well as achieve better precision and accuracy, and it could be used for heavy metals detection.

Abstract:To develop a new method for the determination of sucralose in foods by capillary zone electrophoresis with indirect ultraviolet detection.Methods Samples were extracted with ultrapure water and then centrifuged. The separation was carried out using an uncoated fused-silica capillary. The separation buffer consisted of 3 mmol/L 3,5-dinitrobenzoic acid, 10 mmol/L sodium phosphate, 12 mmol/L sodium hydroxide (pH=12.58) and 0.5 mmol/L hexadecyltrimethylammonium bromide. The separation voltage was -20 kV and the detection wavelength was 200 nm. Quantification was made by external calibration between the corrected peak areas and the concentrations of sucralose.Results The limit of detection and limit of quantitation were 10 and 30 mg/L, respectively. The linear range between the corrected peak area and the concentration was from 30 to 300 mg/L with a correlation coefficient of 0.999 1. The average spiked recoveries of five replicates at three levels (40,0 and 80 mg/L) were 108.1%, 102.6% and 103.5% with relative standard deviations of 1.3%, 1.3% and 1.0%, respectively. The precision of the method was 2.0%.Conclusion The method is simple with minimal sample and reagent consumption. The analysis could be completed within 20 min (6 min for rinsing and 14 min for separation). Sucralose could be baseline separated from sucrose with similar structure. Five kinds of food samples (a total of eight) were analyzed by the current method. No sample was found to exceed the permitted level.

Abstract:To establish an on-line GPC-GC-MS analytic method to determine 17 pesticide residues simultaneously and rapidly in animal derived foods including pork, egg, milk and fat.Methods The pesticide residues were extracted from samples with acetonitrile assisted by n-hexane, salting-out with NaCl and separated through acentric. The supernatant liquid was cleaned up by SPE (NH₂), and detected with on-line GPC-GC-MS system. Results The calibration curves of 17 pesticide residues were linear in the range of 0.85-30 μg/L with correlation coefficients above 0.95. The recoveries of the method ranged from 61.2% to 126%. The limits of detection and the limits of quantification were 0.25-3.00 μg/L (S/N≥3) and 0.85-10.0 μg/L (S/N≥10). Conclusion The method was effective, rapid, sensitive, and suitable for the monitoring of the maximum residue limits (MRLs) of 17 pesticide residues in animal derived foods.

Abstract:Loop-mediated isothermal amplification (LAMP) method was developed to detect fox-derived ingredients in mutton.Methods Four pairs of specific primers (F3, B3, FIP, BIP) were designed, respectively. The sensitivity and specificity test were performed after the LAMP assay was optimized. Then the detection of fox-derived ingredients in mutton was carried out.Results The optimized condition was 0.2 μmol/L each of F3 and B3, 1.6 μmol/L each of FIP and BIP, 0.5 mol/L betaine, 0.4 mmol/L dNTP and 4 mmol/L MgSO₄. 1.0% adulterated fox-derived ingredients could be detected specifically. The limit of detection was 2×10-4 ng/μl.Conclusion This method is highly specific and sensitive, and could be a very useful tool for mutton adulteration detection

Abstract:To study the contamination and distribution of Vibrio parahemolyticus, Vibrio alginolyticu and Vibrio vulnificus in fish, water and underwater deposit from farming, saling and catering of freshwater fish in inland cities in China.Methods All monitoring sites were in Guangxi, Henan, Hubei, Shandong, Sichuan and Zhejiang Provinces. Three kinds of halophilic Vibrio from different samples were analyzed by conventional method such as culturing, isolating and biochemical identification. Results The occurrence was 1.89% and 5.81% for Vibrio parahemolyticus isolated from farming water and freshwater fish, 1.89% and 4.98% for Vibrio alginolyticu, and 1.14% and 0.83% for Vibrio vulnificus. The occurrence increased rapidly in markets from temporary keeping water and freshwater fish with 18.47% and 14.93% for Vibrio parahemolyticus, 10.83% and 9.70% for Vibrio alginolyticu, and 3.18% and 3.36% for Vibrio vulnificus. The occurrence of three kinds of halophilic Vibrio isolated from freshwater fish was basically identical between markets and the restaurants.Conclusion The marine Vibrio, Vibrio parahemolyticus, Vibrio alginolyticu andVibrio vulnificus, have been isolated from farming, saling and catering of freshwater fish in inland cities, and it should call attention to the safety of the food chain.

Abstract:The safety status of children's snacks in the rural area of China is serious and directly threatening children's health and even life. Food risk prediction and risk analysis, as effective food control tools, have been accepted and practiced by many countries and could be a potential measure for the safety management of snacks in the rural area.Methods The rural area in Hebei Province was chosen as the study target. Snacks/hazards combinations were recognized through analyzing the official food detection reports released by Hebei Food and Drug Administration from 2014-2015 and questionnaire results from 350 children aged 5-13. Those combinations were divided into nine categories according to the risk levels and consumption frequencies.Results The risk prediction results showed that the nine categories could be divided into four risk matrix. Snacks, including candies, sausage, cakes and instant noodles belonged to the highest risk matrix and should be monitored most frequently. In addition, those snacks like cookies and seasoned pasta, which had been found some safety issues in the past, should also be the main control targets.Conclusion Risk prediction could help to establish risk priority and provide effective suggestion for risk management and risk communication. This study could provide suggestions for local supervision officials to conduct risk prediction and risk analysis and perform better risk management on foods.

Abstract:To investigate and analyze the dietary cadmium exposure of women from heavy metals polluted rural areas of a central province in the central China, PR.Methods 8 local farmed food groups (rice and its products, leafy vegetables, root vegetables, gourd vegetables, legume vegetables, solanaceous vegetables, pork and fishes) were collected from 16 heavy metals polluted rural areas. Cadmium concentration in the food were determined by graphite furnace atomic absorption, and the consumption of the 8 local farmed food groups was evaluated by a semi-quantitative food frequency questionnaire. The health risk was preliminary assessed by comparing the dietary cadmium exposure with provisional tolerable monthly intake (PTMI).Results Among the 8 food groups, the average cadmium concentration of rice and its products was the highest (86.784 μg/kg), followed by solanaceous vegetables (64.060 μg/kg). The average cadmium concentration of pork was 4.862 μg/kg, which was the lowest. The average dietary cadmium exposure of local women per month was estimated to be 22.394 μg/kg BW, accounted for 89.57% of PTMI; the upper 90th percentile of dietary cadmium exposure per month was estimated to be 53.929 μg/kg BW, accounted for 222.27% of PTMI. Rice and its products, as the main contributor, contributed 67.52% of dietary cadmium exposure. Conclusion The dietary cadmium exposure of women from heavy metals polluted rural areas of one province of central China was at a relatively high level, and a part of the women's dietary cadmium exposure exceeded the PTMI. In addition, the dietary cadmium exposure contribution of rice and its products was the highest.

Abstract:To explore the working pathway of the revision for “national food safety standard grains”.Methods Comparative analysis between China standards and CAC standards and expert panel discussion was used to discuss the key indicators related to the safety of grain product. Results According to the function of national food safety standard, the working pathway of the revision was discussed. The revision of the safety standard of grain products should give full consideration to the special features of grain products and focus to the food safety indicators by compiling the existing national standards and considering the policies for grain products in order to better protect the health of consumers.Conclusion The mandatory food safety standard of grain in the system of grain product standards should focus on the safety requirements of grains and keep continuous improvement.

Abstract:To understand the contamination of Proteus in cooked foods and quick-frozen food made of rice and flou from Shijiazhuang markets, and to study the characteristics of extended-spectrum β-lactamase production and drug-resistance.Methods Food samples were collected, and the isolated strains were identified and testing for susceptibility with BD Phoenix expert system. Results Total prevalence of Proteus was 22.0% (83/377), and the contamination rates were 20.8% (32/154), 28.7% (43/150) and 11.0% (8/73) in cooked foods, raw and cooked quick-frozen food made of rice and flour. Proteus counting range was 10³-10⁹ cfu/g. Susceptibility results showed that 80 Proteus mirabilis were naturally resistant to tetracycline and polymyxin. In addition, the highest rate of resistance was to ampicillin (36.3%), followed by cefazolin (27.5%). 3 Proteus vulgaris were naturally resistant to tetracycline, polymyxin, ampicillin and cefazolin, and the highest rate of resistance was to chloramphenicol (100%). All strains were sensitive to amikacin, meropenem and piperacillin. In all Proteus mirabilis isolated strains, ESBL-producing strains accounted for 25.0%-33.3%. The multi-drug resistant (MDR) strains accounted for 12.5%-33.3%.Conclusion The contamination of Proteus in cooked foods and quick-frozen food made of rice and flour was quite serious. Higher levels of producing ESBLs and MDR existed in food isolates which had a potential foodborne risk.

Abstract:To understand the contamination characteristics of foodborne pathogens in sea foods from Yellow Sea and Bohai Sea area of Yantai, and also find the background values of foodborne pathogenic bacteria contamination to provide basis for market supervision, consumption guidelines and risk warning.Methods The national food safety standard (GB 4789), food microbiological examination, was used to detect the different foodborne pathogens. The risk assessment of Vibrio parahaemolyticus from sea food was calculated by a swift quantitative microbiological risk assessment tool (sQMRA). Results The total contamination level of Vibrio parahaemolyticus from sea food samples was 19.62%. Shellfish and crustaceans had higher contamination level than fish and seaweeds, which were 26.42%, 20.00%, 10.00% and 10.00% respectively. Oyster had the highest contamination level in shellfish which was 31.03%. The risk values of Vibrio parahaemolyticus when ingested heated sea food for general population of Yantai was 2.97×10-7, and the prevalence rate of Vibrio parahaemolyticus was 6.03×10-6 times per person per year. The prevalence rate was the highest during July and September.Conclusion The fresh sea food of Yantai sea area from Yellow Sea and Bohai Sea was mainly contaminated by Vibrio parahaemolyticus. There was a potential risk of infection for general population when ingested contaminated sea food, particularly during the third quarter.

Abstract:To evaluate Chinese adult dietary lead intake level and its potential health risks.Methods Concentration data of lead of 21 food categories in 2014, food consumption data from Chinese Nutrition and Health Survey 2002, and beverage consumption data from Chinese Beverage and Alcholic Beverage Consumption Survey 2013 were used to calculate dietary exposure of lead among Chinese adult population by simple distribution model. The margin of exposure (MOE) method was adopted to assess the potential health risks of dietary lead exposure. Results The MOE values of mean, median and high consumption (P97.5) dietary lead exposure among all adults were over 1, so did the values among different areas and age-gender specified population. However, there were 0.61% of adults whose MOE values were less than or equal to 1. It was indicated that the main sources of dietary lead were rice and its products, flour and its product, vegetables and meat, which contributed more than 70% of total dietary lead exposure.Conclusion It suggested that the potential health risks caused by dietary lead exposure in Chinese adult population was of low concern, but there still were 0.61% of the population need further consideration.

Abstract:In order to assess the potential risk of dietary exposure to sodium cyclamate in Chinese population.Methods The limits of sodium cyclamate in foods and consumption of these foods were used for exposure assessment. The exposure of sodium cyclamate obtained in the present research was compared with the acceptable daily intake (ADI) which was established by JECFA.Results The average exposure of sodium cyclamate exposure of whole Chinese population was 0.97 mg/kg BW, accounted for 13.86% of ADI, while high exposure (P97.5) was 6.69 mg/kg BW and accounted for 95.52% of ADI. According to SCF, the intake of sodium cyclamate exposure of high exposures in people under 2-3 years, 4-9 years, 10-17 years (P97.5) exceeded ADI, was 146.32%,86.78%,9.19%, respectively. Pastry, shell cooked nuts and seeds, were the main sources of sodium cyclamate exposure compared with others.Conclusion The sodium cyclamate dietary exposure of whole Chinese population was below the ADI. The sodium cyclamate exposure in high exposures (P97.5) should be paid more attention to.

Abstract:This study investigated rural residents' risk perception on food additives and the influence factors.Methods Rural residents from seven provinces of China was randomly enrolled into the survey and filled the self-reported questionnaire. Results Participants perceived food additives as high risk. About 65.5% of the participants misunderstood the concept of food additives, perceiving illegal adulteration as food additives. Despite of knowledge, social trust on government and food industry significantly affected the risk perception.Conclusion The key strategy should be building trust on the governments to help rural residents construct a scientific and rational perception of food additives.

Abstract:To find out the cause of a food poisoning event, identify the source of infection and risk factors and to control the spread of outbreak.Methods Case research and investigation were carried out adopting the method of field epidemiological investigation. Samples were collected for laboratory test and enterotoxin gene identification. Incubation period was calculated by epidemiological curves to identify the poisoning meal time and food. Results Nausea, vomiting and diarrhea occurred predominantly in 27 confirmed poisoning cases, accompanied by abdominal pain, headache and dizziness in some cases. The poisoning meal time was lunch and supper in December 10^th, and the poisoning food was barbecue rice. The cause of the disease was Staphylococcus aureus enterotoxin A. The similarity of PFGE pattern between strains of Staphylococcus aureus was 100%, sharing high homology. Toxin genes were confirmed as enterotoxin A by RT-PCR.Conclusion The food poisoning occurring in the same place at different meal times was caused by Staphylococcus aureus enterotoxin A. Cross contamination was the most important factor of transmission of Staphylococcus aureus. Supervision should be strengthened in critical control point for restaurants to avoid recurrence of similar incidents.

Abstract:Aflatoxin M₁ is the hydroxylated metabolite of aflatoxin B₁ and it can be found in milk and dairy products. Aflatoxin M₁ have teratogenic and carcinogenic effects on human. With increasing concerns about food safety issues, aflatoxin M₁ contamination in the dietary calls for more and more attention. This study analyzes the contamination of aflatoxin M₁ in milk and dairy products based on categories, seasonal and regional differences, summarizes the present research progress on rapid detection technique in liquid chromatography and immunoassay.