Abstract:To develop a method for identification of B-type fumonisin-producing Aspergillus nigerat genetic level. Methods The DNA and mRNA extraction method, conditions fo ramplification of eight key genes of B-type fumonisin-producing gene cluster of Aspergillus niger by polymerase chain reaction (PCR) and reverse transcription-PCR (RT-PCR) were optimized. The expression products were analyzed. Results The DNA of eight key genes related to B-type fumonisin biosynthesis were detected in all 19strains of Aspergillus niger. fum6,fum14,fum19 were the most predominant genes in Aspergillus niger in association with fumonisin production, but the mRNA expression level of the 8key genes were different which leaded to different B-type fumonisin produce ability.Conclusion B-type and non-B-type fumonisin-producing Aspergillus nigercould not be distinguished at DNA level. DNA in combination with mRNA expression level was needed to identify B-type fumonisin-producing Aspergillus niger.

Abstract:Using DNA barcode to identify species of puffer fish in roasted fish fillet and dried fish sold in Beijing and Xiamen markets.Methods Genome DNA from roasted fish fillet and dried fish was extracted, amplified by specific primer of cytochrome oxidase subunit Ⅰ of puffer fish and sequenced. BLAST comparison was made between the sequencing results and Genebank, and phylogenetic tree was built. Results Specific straps were amplified by PCR in 15out of 27samples. According to the BLAST comparison and phylogenetic tree analysis, the 15samples were classified in different puffer fish species.Conclusion Some commercial roasted fish fillet and dried fish was made by puffer fish in Beijing and Xiamen. The supervision should be strengthened and the processing procedures should be standardized to avoid tetrodotoxin poisoning.

Abstract:To develop a colloidal gold strip for detection of Listeria monocytogenenes (LM) based on the monoclonal antibody against LM internalin A (InlA) protein.MethodsAfter analyzing the antigenic epitopes of LM inlA full-length gene encoded protein using DNAStar software, the target inlA gene fragment was selected to construct the prokaryotic expression plasmid, and the recombinant InlA protein was prepared by inducible expression and used to immunize the BALB/c mice. The specific monoclonal antibody against LM InlA protein was prepared. Based on the principle of double-antibody sandwich method, the colloidal gold strip was developed, and its specificity, sensitivity, and stability were evaluated. ResultsTwo hybridoma cell lines were identified to specifically secret anti-InlA monoclonal antibodies, and the antibody subclasses were IgG1subtype. The antibody titers of acites were 1∶64000. The colloidal gold strip showed positive reaction with the LM strains, but showed negative reactions with Listeria other than LM, as well as other food-borne bacteria such as Streptococcus, Salmonella typhimurium and EHEC O157∶H7. The detection limits for LM pure cultures and analog samples were 2.4×10⁵and 4.0×10⁶cfu/ml, respectively. The strip could be stored at 4℃ for more than 16weeks.ConclusionThe colloidal gold strip could be used to detect LM in food sample rapidly, sensitively and accurately.

Abstract:To establish a multiplex PCR (mPCR) method to identity Campylobacter jejuni and Campylobacter coli.MethodsSpecific primer pairs were designed based on the sequence of 16S rRNA gene, hippuricase gene and 16S-23S rRNA gene. 37strains were detected by the mPCR and ⁱⁿgene CAM nested PCR assay kit. ResultsThe results showed that the species-specific product could be detected after amplification of the DNA template of C.jejuni and C.coli, while other strains could not be detected. The sensibility for detection of C.jejuni and C.coli was 0.81and 0.93pg/μl, respectively. The coincidence rate mPCR method and nested PCR assay kit was 100%. Coincidence of the two methods with the national standard method were also over 97%.ConclusionThis new method was rapid, convenient, highly specific, sensitive and repeatable. It could be used for rapid identification of Campylobacter spp..

Abstract:A Taqman real-time PCR was developed to detect cereal-derived ingredients adulterated in dairy products.MethodsThe universal primers and probe for cereals were designed according to the homogeneous region of rbcL gene by blasting the rbcL gene of rice, maize, wheat, sorghum and barley. And the assay was evaluated by universality and sensitivity test. Meanwhile, its practicability was verified using simulated samples and market samples. Resultsimplicated that the primers-probe system could detect DNA fragments of rice, maize, wheat, sorghum and barley with no cross-reaction to banana, jujube, pineapple, strawberry, tomato, peanut, soybean, bovine, ovine which may occur in dairy products(Ct＞35). The detection limit was 0.01ng for pure wheat DNA and 0.5% for each of five cereals in dairy mixtures. 14market dairy samples were analyzed for cereal ingredients, and were all consistent with their food labels.ConclusionThe study suggested that the developed Taqman real-time PCR method was a rapid, sensitive and efficacious detection assay for cereal-derived ingredients in dairy products.

Abstract:In order to investigate the effects of bisphenol A (BPA) on testicle tissue of mice from toxicologic pathological perspective, and providd morphological evidences of BPA toxicity.Methods108SPF CD-1male mice were randomly allocated into four groups with BPA concentration of 0,0, 300and 600mg/kg BW. All BPA groups were administrated orally with different doses for 8weeks continuously. Then testicles were taken and fixed to perform pathological observation and analysis. ResultsAfter 8weeks of BPA administration, body weight and testicle index of BPA groups were decreased compared to control group. Degeneration and necrosis were observed in sustentacular cell of seminiferous tubule, and spermatozoon number decreased. Karyopyknosis and maldevelopment were occurred at acrosome vesicle and cap of spermatogenic cells observed by TEM. Immunohistochemistry test showed that NF-κB and Caspase-3expression were up-regulated (P＜0.01or P＜0.05) in BPA groups compared to control group. TUNEL test indicated that the number of apoptosis positive cells was higher in BPA groups than control group (P＜0.01).ConclusionDifferent doses of BPA could lead to testicle tissue damage at different level, and induce cell apoptosis of testicle.

Abstract:To investigate the influence of trace element strontium on the content of rats' serum ALT, AST, BUN, Cr, LDH, HDL, triglycerides and total cholesterol.MethodsWistar rats weighing 150-170g, half male and half female, were randomly divided into group A, B, C, D (mineral water with Sr 2,4, 6,8mg/L) and group E (tap water). Each group had 42rats(n=42). 6rats in each group were randomly sacrificed at 0,1, 2,3, 4,5and 6th month, and blood samples were collected. Serum ALT, AST, BUN, Cr, LDH, HDL, triglycerides and total cholesterol were tested. Hearts, livers and kidneys were stained by HE for morphology analysis. ResultsThere was no significant difference in the content of serum ALT, AST, Cr, LDH, HDL, triglycerides and total cholesterol between group A, B, C, D and E at each time point.(P>0.05). The contents of BUN in group A was significantly lower than that in group E (P<0.05). There was no significant difference in the morphology of kidney, heart and liver between group A, B, C, D and E. ConclusionTrace element strontium had no significant effect on the content of serum ALT, AST, LDH, BUN, Cr, HDL, triglycerides, total cholesterol, and the morphology of kidney, heart and liver in rats.

Abstract:To optimize the reaction conditions and to analyze the DNA detection limit of a multiplex PCR method for simultaneous detection of Salmonella, Staphylococcus aureus, Escherichia coli O157∶H7, Listeria monocytogenes and Shigella.MethodsBased on the invA gene of Salmonella, the 16S rDNA gene of Staphylococcus aureus, the eaeA gene of Escherichia coli O157∶H7, the hlyA gene of Listeria monocytogenes and the ipaH gene of Shigella flexneri, five pairs of primers were designed for multiplex PCR amplification. The reaction conditions were optimized and the detection limit was confirmed. ResultsThe optimal concentration of primers for Staphylococcus aureus, Salmonella and Shigella flexneri was 0.25,0.4μmol/L for Listeria monocytogenes, and 0.3μmol/L for Escherichia coli O157∶H7. The optimal magnesium ion concentration was 2.25mmol/L, the annealing temperature was 60℃. The DNA detection limit of this method was 6.4pg for Staphylococcus aureus, 32pg for Salmonella enteritis, 32pg for Escherichia coli O157∶H7, 800pg for Listeria monocytogenes and 160pg for Shigella Flexnei, respectively.ConclusionThrough optimization of reaction conditions and analysis of detection limit, the results provided a basis for the simultaneous detection of these five pathogens and had a significant prospect for application.

Abstract:To establish a quick checking method of enterotoxins genes in food-borne Listeria monocytogenes by multiplex polymerase chain reaction (MPCR) and denaturing high-performance liquid chromatography (DHPLC).MethodsPrimers for detection of hly, prfA, inlA and inlB were designed and PCR system was optimized. Products were detected by DHPLC for quick detection. Thirty-two strains were tested with PCR method, sensitivity was determined with various concentration of standard strains. ResultsThe peak order of PCR products was inlB, hly, inlA, prfA, and amplified fragment size was 146,0, 255and 388bp respectively. This method has good specificity, and the lowest amount of detecting was 280cfu/ml.ConclusionThis method can well meet the requirements of actual food microbe testing.

Abstract:To analyze the ability and accuracy of protein microarray for body iron stores (BIS) and iron deficiency diagnosis.MethodsThe protein microarray was compared with commercially available traditional tests for serum ferritin and soluble transferrin receptor, evaluated by indicator including the sensitivity, specificity, Youden's index, likelihood ratio, Kappa index. The BIS results were compared between protein microarray and immunoturbidimetry by paired t test. ResultsThe protein microarry showed higher sensitivity, better specifcity and coherence with immunoturbidimetry on iron deficiency estimates. At the same time, more BIS insufficient were discoverd by protein microarray.ConclusionThe protein microarray, a new rapid diagnosis technique, could be used to simultaneously detect SF and sTfR, opposed high diagnosis potencial on iron deficiencyestimates and it was valuable for more application research.

Abstract:A method was developed for the determination of hexavalent chromium in foods.MethodsSamples were microwave extracted with 10% hydrochloric acid for 15min at 120℃.Then extracts were separated with Waters MAX cartridge (500mg, 6cc) and eluted by 5% ammonia water. The hexavalent chromium was indirectly quantified by AAS. ResultsThe lineary range was satisfying within 1-10μg/L, and the correlation coefficients were above 0.999. The limit of detection was 0.0087mg/kg. The recoveries were 90.24%-108.06% with relative standard deviations of 3.19%-6.01%.ConclusionThe method was simple, fast, sensitive, accurate and suitable for the determination of hexavalent chromium in vegetables, fruits, grain and health foods.

Abstract:The method for the determination of dietary iodine in meat was developed by inductively coupled plasma-mass spectrometry (ICP-MS).MethodsThe samples were extracted by tetramethylammonium hydroxide and hydrogen peroxide in ultrasonic bathing at 60℃ for 3h and analyzed by ICP-MS after removing fat and protein. ¹²⁸Te was used to eliminate the matrix interference. ResultsUnder the optimal conditions, this method showed excellent linearity in the range from 1to 200μg/L with a correlation coefficient of 0.9998. The limit of detection was 2.3μg/kg. The relative standard deviations were no more than 5.7% (n=7). The average recoveries of iodine were in the range from 80.0% to 96.6%.ConclusionThis method was efficient and practicable for determining dietary iodine in meat.

Abstract:The aim was to establish a method for the simultaneous determination of 2kinds of cholesterol oxidation products (COPs:7-ketocholesterol,cholesta-4,6-dien-3-one) by HPLC.MethodsThe mixture of samples and Florisil packing were grinded, then packed to a syringe column. The extraction and purification of the samples were carried out with one-step using acetonitrile as eluting reagent. With anhydrous ethanol as mobile phase, the two components were determined by liquid chromatography under 240-285nm. ResultsThere was a good linearity in the range of 0.25-100μg/ml and the correlation coefficients were greater than 0.9993. The detection limits for 2COPs were 0.015and 0.045μg/g, respectively. Under the optimal conditions, the recovery rates of the two target analytes were between 74.1%-97.0% and the relative standard deviations (RSDs) were no more than 5.57%.ConclusionThis method is suitable for the determination of cholesterol oxides in chicken liver.

Abstract:Combined with food safety enforcement practices, this article analyzes the problems in the current Food Safety Law including recheck agency selection,process monitoring,using expired food additives, centralized tableware disinfection, employee health management, administrative responsibilities of accidentunit and other aspects. At the same time, this article proposes the appropriate legislative responses to solve these problems including improving the mechanism of punishment, implementing food standards throughout the entire process of food processing, bring centralized tableware disinfection into food safety laws, implementing corporate liability, changing regulatory approach and advancing the construction of credit system and other aspects.

Abstract:This paper briefly introduces the food safety supervision system, legal system and main regulatory measures of Singapore and Hong Kong, China and put forward the improvement of food safety supervision in mainland China based on their experience.

Abstract:To provide basis for strengthening the management of food labels and identified of food adulteration in Suzhou area,compared the meat source components with the label content.Methodsmeat species of animal source food in Suzhou region was detected using Taqman real-time PCR assays, and compared with the label, identification of food adulteration. ResultsThe test samples of 90cases involved 32production units, the overall is not coincidence rate was 25.6% (23/90). The detection of beef and its products in 44cases, 12cases were inconsistent with the label, there are 8cases of samples with pork partly replace beef; 1case with duck part instead of beef sales; In addition has 3cases do not contain beef ingredients, there are pigs, chicken, duck meat outside source sex composition of meat. Detected mutton and its products in 16cases, 2cases of samples are replaced mutton sold with duck, 3cases of mutton samples mixed with part of the composition of pig; Among them 1case sample there is a single sample doped two exogenous meat phenomenon, in addition to the mixed with pig source sex also detected duck source sex composition. Detection of pork and its products (19cases), including 2cases of samples containing the tag did not indicate the composition of chicken. Of the 11cases of mixed meat sample inspection, were 4cases of which components do not tally with the tag, mainly cheap chicken instead of/partly replacing relatively high price of beef and pork.ConclusionMeat products adulteration was the common situation, with cheap meat instead of some or all high prices meat. Carrying out meat adulteration detection has positive significance to regulate meat market. In addition, 3cases of unknown provenance composition of beef samples suggested that expanding the detection range is neccessey, nip in the bud.

Abstract:In order to investigate the contamination situation and understand the dynamic changes of Salmonella contamination in food, the food-borne Salmonella in retail meats was detected and analyzed during 2010and 2012in Urumqi, Xinjiang.MethodsThe Salmonella in retail meats (chicken, lamb, beef, pork) was isolated, identified and further serotyped according to National Standard GB/T 4789.1-2010. ResultsA total of 1406samples of retail meats were examined from 2010to 2012, the infection rate of Salmonella was 9.14% in chicken, 9.06% in pork, 8.05% in mutton and 6.44% in beef. Among 123strains recovered in the study, 4serogroups and 7serotypes were identified as S.Enteritidis (n=17), S.Sao (n=9), S.Tarshyne (n=8), S.Uganda (n=6), S.Concord (n=3), S.Thomson (n=3) and S.Derby (n=2), undefined 75seroproups.ConclusionThe contamination of different Salmonella phenotypes existed in retail meats in Urumqi and could not be ignored, and the hygiene and quarantine of retail meats should be strengthened to prevent and control the salmonellosis.

Abstract:To study the pollution levels of illegal nitrofuran veterinary drugs and β-agonist residues of marketed raw meat in Yantai.MethodsAccording to detection methods of standard operating procedure for the detection of veterinary drugs and illegal drugs in the 2013National Food Contamination and Harmful Factors Risk Workbook, 30samples of marketed pork, mutton, beef, liver in bulk in Yantai were detected for nitrofuran and its metabolites (furazolidone, furaltadone, nitrofurazone, nitrofurantoin) and β-agonists (clenbuterol, salbutamol, ractopamine, terbutaline). ResultsTwenty-eight samples were qualified(93.3%) and clenbuterol was detected in two samples. Six beef samples and four mutton samples were qualified and had the quarantine identifications. The pass rate of pork was 93.3% (14/15). Two pork samples had no quarantine identification, but they were qualified. The pass rate of liver samples was 80% (4/5), of which 1sample had no quarantine identification, and was unqualified.ConclusionOverall quality of marketed meat and meat products in Yantai was good. Nitrofuran and its metabolites were not detected, but clenbuterol was detected. We should enhance the monitoring and supervision.

Abstract:The types and characteristics of contaminated bacteria in health foods were investigated.Methods38batches of health foods were analyzed according to National food safety standard GB 4789-2010, and bacteria were identified by automatic microbial identification system. Results69contaminated bacteria were isolated from 38batches of health foods. Pathogens and opportunistic pathogens were isolated when taking examinations of Coliforms, Samonella and Staphylococcus aureus.ConclusionMicrobiological quality of health foods can be improved by control of raw materials, environment, strict disinfection and sterilization.

Abstract:To investigate the status of nutrition label on pure milk products in Guangdong Province.MethodsPure milk samples were collected from five regions, including the cities of Guangzhou, Shenzhen, Maoming, Qingyuan and Meizhou. The nutrition labels and ingredient tables on the samples were analyzed. ResultsAll of the 68pure milk samples were labeled with amount of energy and values of the core nutrients, but some mislabeling were found. For example, some samples weren't labeled the nutrient reference values (NRV) percentage, the units of energy and nutrients were mislabeled, and the unit of sodium content was labeled by milliliter.ConclusionSince January 2013, the implementation of National Food Safety Standard General Nutrition Labelling of Prepackaged Foods, it has made great achievements for standardized nutrition labeling. However, according to the above results, the relevant authorities is still necessary to publicize the standards and guide the enterprises and food importers to abide the standard requirements.

Abstract:This paper analyzed and compared the key indicators in the current standards of edible vegetable oil in order to find the problem of the existing standards. The construction of national safety standard for edible vegetable oil was discussed with reference to codex standards.

Abstract:As one of the stakeholders for food safety risk communication, media reports on food safety are often far away from scientific criteria, which result in communication difficulties. Based on content analysis of 125food-related investigative reports of CCTV Weekly Quality Report, this paper revealed how news value bias may affect expert-novice cognitive gap on risk issues.

Abstract:The analytical methods for phthalate esters in recent years are reviewed and evaluated, and the future prospect is discussed.

Abstract:This paper gives an overview about contamination status, target tissue of detection, virus concentration and detection method, the urgent problem and development direction of norovirus in shellfish. The objective of the paper is to provide a reference for developing the norovirus detection standard and the shellfish import and export trade.