Abstract:Objective To integrate and improve the method for the determination of aluminum in food in order to provide data base for establishing a new National Food Safety Standard.To carry out an investigation on the aluminum content in flour products in Guangdong province to provide data base for evaluating human exposure to aluminum through diet and to standardize the use of aluminum-containing food additives.Methods Improved the digestion system and chromogenic system in the method of GB/T 5009.182—2003 and applied to detect the content of aluminum in wheaten food in which aluminum-containing food additives had been added as a leavening agent;and the background values of aluminum in food was detected by GB/T 23374—2009 and graphite furnace atomic absorption spectrometry.Results A total of 2 369 varied wheaten food samples were collected from supermarkets,grocery stores or kiosks located in different cities and villages in Guangdong province from 2006 to 2010.The results showed that the average contents of aluminum in deep-fried products like dough sticks and deep-fried cakes,steamed products like steamed stuffed bun and steamed bread,and bakery products like bakery bread were 321.0,201.0 and 26.2 mg/kg respectively,the eligibility for GB 2760—2011 in these three kinds of food listed above were 18.5%,31.6% and 95.2% respectively.Conclusion It is proposed to modify the GB/T 5009.182—2003 by adding graphite furnace atomic absorption spectrometry and integrating the GB/T 5009.182—2003 with GB/T 23374—2009 to establish a new National Food Safety Standard.The surveyed data continuously collected in the past 5 years indicated that aluminum-containing food additives had been widely used in deep-fried and steamed wheaten food and lead to a prevalence of exceeding the standard limit value of aluminum.FAO/WHO propounded in the year 2006 that the(provisional tolerable weekly intake) PTWI was 1 mg/kg BW.According to this guidance value,more attention should be paid to the problem of aluminum contamination through the ingestion of wheaten food,which might do harm to the health of residents in Guangdong province.

Abstract:Objective To investigate the inhibitory effect of L-arabinose and L-arabinose combined with acarbose on the activities of α-glucosidase in vitro.Methods The homogenate of α-glucosidas prepared by scraping mucosa from small intestine of rats was incubated with sucrose,maltose and α-dextrin(in a final concentration of 60 mg/ml,20 mg/ml and 20 mg/ml respectively) as optimal reaction systems to determine the inhibitory effects of L-arabinose on the activities of α-glucosidase(IC50) and the type of inhibition.Results L-arabinose inhibited the activities of α-glucosidase in a dose-dependent manner,especially selectively inhibiting the activity of sucrase in an uncompetitive manner(Ki,0.558 mg/ml) with an IC50 of 0.164 mg/ml.The combination of L-arabinose with acarbose might enhance the effect of inhibition,especially while using sucrose as substrate.Conclusion L-arabinose inhibited the activities ofα-glucosidase,especially the activities of sucrase.The combination of L-arabinose with acarbose might increase the inhibitory effect.L-Arabinose might have good prospects for practical application in sweet food.

Abstract:Objective To understand the molecular epidemiology traits of Vibrio parahaemolyticus in Jiangsu and surrounding areas.Methods Biochemical identification,tdh and trh gene detection,serological typing and pulse-field gel electrophoresis(PFGE) were applied to 63 Vibrio parahaemolyticus strains isolated from food poisoning incidents occurred in Jiangsu and surrounding areas in 2010.Results The positive rates of tdh and trh were 79.4%(50/63) and 1.6%(1/63) respectively.The main serological type of strains isolated from patients was O3∶K6(26/57),and that from food was O1∶KUT(4/6).The patterns of PFGE showed that the similarity of groups from A to E was more than 60%.Conclusion Strains isolated from different regions in Jiangsu and surrounding areas were in high homology.The food poisoning incidents occurred in these areas might be contaminated by Vibrio parahaemolyticus strains from the same source.

Abstract:Objective To establish the threshold of toxicological concern(TTC) approach and to apply it in the risk assessment of bis(2-ethylhexyl) phthalate(DEHP) as a model chemical for food contact materials.Methods TTC decision tree approach was established and DEHP was classified into Cramer systems based on both Cramer schematic diagram and Toxtree software to classify DEHP into Cramer systems.DEHP exposure in general population as well as in four age population groups was estimated by using data from the Chinese National Nutrition and Health Survey and data from DEHP surveillance on beverage,vegetable oil,fermented milk,instant noodle,fruit,vegetable-based jelly and fruit jam in China.TTC decision tree approach was used for risk assessment and the exposure was compared with the corresponding TTC value.Tolerable daily intake(TDI)-based risk assessment was also carried out to verify the results from TTC approach.Results DEHP belongs to class I Cramer and its TTC value was 30 μg/kg BW.The maximum dietary exposures of general population and four age groups were 4.06 and 11.10 μg/kg BW,respectively.These exposure values accounted for 13.5% and 37.0% of TTC for DEHP and accounted for only 8.1% and 22.2% of TDI for DEHP.Similar results can be derived from both TTC approach and TDI-based approach.Conclusion TTC decision tree approach is a useful tool for prior screening and primary risk assessment of food contact materials.Dietary exposure of DEHP in Chinese population is low and no health concern is required.

Abstract:Objective To detect Pseudomonas aeruginosa in adult chicken,and provide basis for epidemiological investigation or for the control of related diseases.Methods Suspicious strains were isolated from 49 anus swab samples of adult chicken before slaughtering and examined by oxidase test,pyocyanin test and biochemical identification.Results Eight suspicious strains were isolated from anus swabs,and the positive rate was 16.3%.According to morphological observation,oxidase test,pyocyanin test and biochemical identification,8 suspicious strains were identified as pseudomonas aeruginosa.Conclusion Pseudomonas aeruginosa could be carried by healthy chicken.As a foodborn pathogen,pseudomonas aeruginosa do harms to the human.

Abstract:Objective In order to fulfill the requirement of revising and adding more determination methods and indexes for pesticide residues in the Hygienic Standard for Honey,and to establish a method of detecting 10 pyrethroid pesticide residues simultaneously in honey by GC.Methods Through comparing the type of capillary columns,solvents and solid phase extract columns,it was decided to have the extraction with dichloromethane,cleaned-up with Florisl solid phase extract column,and separation with capillary column DB-17(0.25 mm×0.25 μm×20 m).The residues were quantified with GC-ECD and the area of peaks.Results The recoveries of fluvalinate residues were 77.3%-103.0%,the RSDs were 2.5%-7.5%,the detection limits were 0.000 5-0.005 mg/kg(as the quantity of sample was 5.00 g).Conclusion The method was easy to handle and separate each component,and suitable for the simultaneous analysis of 10 pyrethorid pesticide residues in honey.

Abstract:Objective To determine boron in foods from Guangzhou by curcumin spectrophotometry.Methods Samples were pretreated by dry ashing after alkalified with 1% Na2CO3 and then turned into boric acid under acidic condition.A red compound was formed by the reaction of boric acid with curcumin,which was quantified by spectrophotometry.Results A good linearity was obtained in the range of 0-1 μg/ml,r=0.999 6,and the detective limit was 0.017 μg/ml.The relative standard deviation was 0.09%-6.11%,and the mean recovery was 88.9 %-103.6%.Boron contents in 68 kinds of food from Guangzhou were 2.99-34.73 mg/kg,in fruits were 0.10-4.50 mg/kg and in vegetables were 0.09-2.91 mg/kg.Boron contents in most other samples were low except in 3 samples.Conclusion The method needs only general equipment,and its repeatability,sensitivity and accuracy could meet the requirements of boron analysis in different kinds of food.The concentration of boron in dried fruits,beans and vegetables was higher,and that in fish,meat,egg and grain was lower.Some foods may be added with borax or boric acid unlawfully.

Abstract:Objective A high performance liquid chromatography(HPLC) method was developed for the determination of four kinds of purine in food.Methods Food sample was hydrolyzed with perchloric acid at 100 ℃ for 60 min,and the hydrolyzate was filtrated with membrane.The chromatographic separation was achieved in Waters Atlantis T3(4.6 mm×250 mm×5 μm) column by using 10 mmol/L formic acid amine solution(pH3.6) and CH3OH(99∶1) as mobile phase with a flow rate of 1.0 ml/min at 30 ℃.The detection was performed under Waters 2487 UV detector at 254 nm with a injection volume of 10 μl.Results The HPLC response to these four kinds of purine was linear in the range of 0.05-20.00 μg/ml,r>0.999 9.The average recovery of standard addition was 93.1%-101.3%,and relative standard deviation(RSD) was less than 12.5%.Conclusion The HPLC method for the determination of four kinds of major purine in food was fairly high in accurate and good sensitivity.

Abstract:Objective To establish a method for the detection of 3-nitropropionic acid in sugarcane by solid-phase extraction(SPE) coupled with ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS).Methods Samples were extracted by acetonitrile and cleaned up by Sep-pak NH2 solid phase extraction column.The 3-nitropropionic acid was determined by UPLC-MS/MS.The chromatographic conditions: using Waters ACQUITY BEH C18 column(1.7 μm,50 mm×2.1 mm) with water as mobile phase A and acetonitrile as mobile phase B for gradient elution;keeping the column temperature at 40 ℃ and the samples at 10 ℃ with an injection volume of 5 μl.Results There was a good linearity of the calibration curve for 3-nitropropionic acid standard in the range of 4.0-40.0 μg/kg with correlation coefficient of 0.998.The detection limit of the method was 1.0 μg/kg and the limit of quantification was 4.0 μg/kg.The average recovery at three spiked levels was in the range of 92.5%-93.6%,and the relative standard derivation was lower than 10%.Conclusion The method is simple,rapid,sensitive and accurate,which can be used in the detection of 3-nitropropionic acid in sugar cane.

Abstract:Objective To develop an analytical method for the determination of xylo-oligosaccharides in health foods by high performance liquid chromatography with differential refractive index detector.Methods The samples were extracted and then hydrolyzed(4.6 mm×250 mm,5 μm) with sulfuric acid solution in boiling water bath;neutralized with sodium hydroxide solution;separated on a NH2 column with a mixture of acetonitrile-water(70+30,V/V) as mobile phase;detected by refractive index detector at a flow rate of 1.0 ml/min.Results There was a good linearity of the calibration curve between the peak area and the mass concentration of xylose in the range of 0.30-4.50 mg/ml(r=0.999 9);The relative standard deviations were 1.86%-3.80%(n=6);the recoveries were 90.3%-98.3 % in solid health foods and 89.0%-97.0% in liquid foods.Conclusion This method is found to be simple,rapid,precise and accurate.Therefore,the method can be successfully used for the determination of xylo-oligosaccharides in health foods.

Abstract:Repeated dose 28-day oral toxicity study in rodents(OECD Test Guidelines 407) is widely used to evaluate the general toxicity of chemicals.In 1998,the Organization for Economic Co-operation and Development(OECD) enhanced existing TG 407 to develop new Test Guidelines for screening and testing potential endocrine disruptors.This procedure has been verified by an extensive international validation program.To provide reference for developing endocrine disruptor evaluation system in China,the enhanced TG 407,its progress and its advantages and disadvantages were summarized in this paper.

Abstract:Toxicological experiment data is the important evidence for the safety of chemicals and it plays an important role in the risk assessment and risk management of chemicals.In order to use the toxicological data from different laboratory to serve regulatory toxicology,it needs to establish a set of scientific and feasible criteria to evaluate the quality of experimental toxicological data.But the research about the systematic approach for evaluating the quality of toxicological data has just begun,and lack of a system reaching a broad consensus.This paper reviews the available international toxicological data evaluation system,which may help Chinese experts to establish an evaluation system in China.

Abstract:Objective To provide the limit value of tetrodotoxin in nassariidae for the judgment in regular monitoring.Methods In order to investigate the limit value of tetrodotoxin in nassariidae,the source,content,toxicity,testing standards of tetrodotoxin in nassariidae from relevant documents on tetrodotoxins and paralytic shellfish toxins were compared and analyzed.Results According to the toxicity,nassariidae could be divided into toxic,nontoxic,and seasonal toxic types of nassariidae.The concentration of tetrodotoxin in nassariidae was in the range of 0-177mg/kg.The toxicity of tetrodotoxin is 30 times of paralytic shellfish toxin(comparing their LD50 in mice).Toxic nassariidae(for example,Nassarius rutilans,Zeuxis scalaris,etc.) should be recognized and totally banned to be sold and consumed.The limit value of tetrodotoxin in nontoxic nassariidae and seasonal toxic nassariidae was suggested to be 0.05 mg/kg when tested by the standard method GB/T 23217—2008 Determination of tetrodotoxin in aquatic products.Conclusion The suggested limit value of tetrodotoxin in nassariidae should be reasonable and feasible.The system of monitoring tetrodotoxin in nassariidae has been proposed and perfected.

Abstract:Food safety inspection in China includes two major systems.One is food safety risk monitoring,the other is inspection carried out by different departments responsible for their own food chain segments.The purpose of this article was to help effectively implement the Food Safety Law,improve the quality and efficacy of risk monitoring for better performing duties.The difference and relation of food safety risk monitoring and inspection were discussed;and further development and suggestions were put forward from different angles.

Abstract:Semicarbazide(SEM),a kind of carcinogenic chemical,found in packaging materials for some baby food has attracted a great deal of public attention in 2003.The risk communication experiences of handling SEM by the European Food Safety Authority(EFSA) was summarized in this paper as a case study,in order to provide references for Chinese food safety control agencies in handling similar food safety crisis.

Abstract:Objective To establish and implement HACCP in breeding and production of Spirulina for health food products.Methods Analyzing the hazards in the process of breeding and producing Spirulina,identifying critical control points and improving the corresponding control measures according to GB/T 27341—2009 Hazard analysis and critical control point(HACCP) system-General requirements for food processing plant and GB/T 16919—1997 Edible Spirulina powder.Results HACCP for breeding and production of Spirulina was set up and implemented,good results were obtained,and the problems in the establishment of HACCP were discussed.Conclusion Implementing HACCP is an ongoing process,constant development and complement in practice is needed.

Abstract:Objective To understand the knowledge and attitude of medical staffs on foodborne diseases in Guangdong province,and to assess the effectiveness of training.Methods The knowledge and attitude of foodborne diseases in medical staffs of ten hospitals in eight cities of Guangdong province were investigated by questionnaires.Results The average score of medical staffs before training was 20.31±3.06 for the knowledge and 7.90±1.47 for the attitude on foodborne diseases,while that after training was 23.08±2.65 and 8.94±0.99 respectively,with significant difference before and after training.Conclusion Medical staffs play an important role in the surveillance of foodborne diseases;their cognitive level on foodborne diseases should be improved;carrying out training on their knowledge and attitude of foodborne disease can obtain good effectiveness.

Abstract:Objective To understand the current knowledge related to food safety and risk factors in catering workers,to provide basis for taking effective intervention measures for food safety.Methods Conducting a survey on the knowledge,attitudes and behaviors to food safety with questionnaires in 720 randomly selected catering workers.Results The awareness of food safety knowledge was 60.8%,no difference was observed in subjects from different units or working on different posts,but a significant difference was observed in subjects with different degree of education,different profession,different work experiences and had different training times.The importance of food safety was fully understood by 98.8% of catering workers.And 89.7% of them have generally developed good behaviors and habits for food safety.Conclusion In order to ensure food safety for the masses,it is necessary to enhance training catering workers to improve their food safety knowledge,to develop their good food safety habits and to regulate their professional behavior.

Abstract:Objective To understand the prevalence of foodborne pathogenic bacteria and the excess of some metals and food additives in Taiyuan in 2010,in order to conduct surveillances on the food safety risk factors.Methods Samples were selected from major purchasing places randomly.A total of 540 samples in 8 categories were detected for foodborne pathogens,and 230 samples for some metals and food additives according to the national standard methods.Results The contamination rate for pathogenic bacteria in foods was 10.37%,the exceeding standard rate for some metals and food additive was 9.09%.The contamination rates of pathogenic bacteria in foods in different kinds of packages and from different retail outlets were significantly different.The exceeding standard rates of some metals and food additives in different retail outlets were significantly different.Conclusion The contamination rate for pathogenic bacteria and the exceeding standard rate for some metals and food additives in foods were rather high in Taiyuan,especially in bulk foodstuffs and foods in fair trade markets.

Abstract:Objective To investigate the contamination of Salmonella in chicken during cultivation and slaughter process,and to find out the possible sources of infection.Methods Based on the Standard Operation Procedures in the handbook of National Surveillance on Foodborne Pathogenic Bacteria,210 anal swabs from living chicken and 204 samples from the meat of whole chicken were collected and analyzed for the contamination of Salmonella.Results Of the 210 anal swabs,23 Salmonella strains were isolated(detection rate 10.95%) and of the 204 whole chicken samples,71 Salmonella strains were isolated(detection rate 34.80%).The serotypes of Salmonella detected in anal swabs and whole chicken samples were different(χ2=15.7,P<0.001).There were 22 Salmonella Indianas isolated from 23 anal swabs,and 35 Salmonella Indianas and 22 Salmonella Albanies isolated from 71 whole chicken samples.Conclusion Positive detection rate of Salmonella from whole chicken samples was higher than that from anal swabs(χ2=33.5,P<0.001),the source of Salmonella in anal swabs and meat samples was different.Cross contamination may be existed in whole chicken meat samples.

Abstract:Objective To investigate the hygienic status of health foods in markets.Methods Referencing to National Standard GB/T 4789.14—2003 and Industry Standard SN 0176—92,Bacillus cereus was detected by automated microbial analysis system for samples selected from 225 batches of 12 varieties of health foods on markets.Results Bacillus cereus was confirmed in 12 batches of health foods.There was a higher rate of contamination for spiraling tablets(60.0%) and calcium tablets(21.1%).Conclusion The results would provide references for health foods production,processing,sterilization,the standards for hygienic examination and inspective administration.

Abstract:A public solicitation for food safety national standards applications was initiated at the end of 2010 by the Ministry of Health.1231 copies of standard project proposal received in 2011 were analyzed.The standards project proposal categorized as "test methods and procedures" and "food additives" accounted for 35.8% and 29.7% respectively;standards project proposal from administrative units and their institutions accounted for 76.1%;the top three areas submitted the highest amount of standards project proposal were Beijing,Shanghai and Shandong.Some issues reflected from the applicants were lack of knowledge and understanding of food safety standards,and social concerns were not consistent with the development trend of the food safety standards system.All standards project proposal collected in this paper were sorted and analyzed;some suggestions were proposed in order to provide reference for the national food safety standards application in the future.

Abstract:Sau-PCR is a novel amplification technique for tracing the genetic fingerprint of microorganisms.Based on the digestion of genomic DNA with restriction endonuclease Sau3AI and subsequent amplification with primers whose core sequence is based on the Sau3AI recognition site,the reproducibility of the assay was as high as amplified fragment length polymorphism(AFLP)and is as quick and easy as random amplified polymorphic DNA(RAPD).Nowadays,Sau-PCR has been gradually used to determine the source of food pathogens and monitor the epidemiology of nosocomial infection.The principle,technical characteristics and the application of Sau-PCR were introduced in this paper.

Abstract:Monitoring banned dyes in food is one of important items in food safety surveillance.Analytical methods for banned dye residues in food,including sample extraction,sample clean-up and instrumental detection,were reviewed.

Abstract:Microcystin(MC) is a group of cyclic heptapeptide hepatotoxins produced by cyanobacteria in freshwater.With the increasing of water pollution,more attention have been paid to the potential health risks of MC on animals and human.The distribution and accumulation of MC in different aquatic products were described in this review,in order to investigate the regular pattern of MC contamination and to provide reference for evaluating the safety of aquatic products and preventing MC pollution.