Abstract:The construction of a healthy China cannot be separated from the improvement of the national nutrition and health level， and the improvement and upgrading of the national nutrition and health level cannot be separated from a solid legal system and policy improvement. This paper studied the nutritional laws of the United States and Japan， analyzed and summarized the experiences of the two countries to improve the relevant laws and policies of our country， and to promote the construction of healthy China.

Abstract:Objective To study the prevalence and antimicrobial resistance characteristics of Salmonella enterica serovar typhimurium（S. typhimurium）and monophasic S. typhimurium from clinical patients and food in Henan Province from 2015 to 2022.Methods Three hundred and ninety-nine strains of Salmonella from food and clinical patients in Henan Province were serotyped according to the Kauffmann White scheme by slide agglutination and multiplex real-time PCR method. Microbroth dilution method was used to test antimicrobial resistance of S. typhimurium. Statistical analysis was carried out using Chi-square test.Results Three hundred and ninety-nine strain were composed of two hundred twenty-five monophasic S. typhimurium （56.39%） and one hundred seventy-four S. typhimurium. The imipenem and trimethoprim/ sulfamethoxazole resistant isolates were found since 2017. The antimicrobial resistance rate of two Salmonella strains to ampicillin， chloramphenicol and tetracycline was higher， reaching more than 50%. The antimicrobial resistance rate of monophasic S. typhimurium to ampicillin and gentamicin was significantly higher than that of S. typhimurium （P<0.05）. The resistance rate of S. typhimurium to cefazolin was significantly higher than that of monophasic S. typhimurium （P<0.05）. Two serotypes of S. typhimurium were resistant to over 60% of three classes or more antimicrobial agents. The common multiple dominant antimicrobial resistance spectrum was ampicillin-chloramphenicol-trimethoprim/sulfamethoxazole-tetracycline pattern.Conclusion Monophasic S. typhimurium had replaced S. typhimurium as predominant serotype in clinical patients in Henan Province. Two serotypes of S. typhimurium strains are generally antimicrobial resistant and the multi-antimicrobial resistance patterns serious. In order to make effective interventions and reduce the spread of S. typhimurium. The study results suggest that the detection rate of foodborn S. typhimurium should be strengthen as well as the antimicrobial resistance of monophasic S. typhimurium.

Abstract:Objective To understand the diarrhea-type virulence genes， the antimicrobial resistance and the molecular typing of emetic Bacillus cereus from the pre-packaged pastries in Taizhou City.Methods The Polymerase Chain Reaction （PCR） method was used to identify the vomiting strains of 97 Bacillus cereus strains which were isolated from pre-packaged pastries in Taizhou and detecte whether the vomiting strains carry diarrhea virulence genes. The sensitivity of the vomiting strains to 19 antibiotics was tested by disk diffusion method， and the molecular typing was carried out by multilocus sequence typing technique.Results The results showed that five emetic Bacillus cereus stains were detected of 97 Bacillus cereus strains and divided into ST 26 and ST 1186 two types. Non-hemolytic enterotoxin gene nhe， enterotoxin genes entFM and bceT were the main diarrhea-type virulence genes of the five strains. The five strains were completely resistant to penicillin， ampicillin and cefotaxime. The resistance rates to cotrimoxazole， rifampicin and cefazolin were 80%（4/5）， 40%（2/5） and 20%（1/5）， respectively. The sensitivity rates of amoxicillin， clindamycin and cefoxitin were 40%（2/5）， 80%（4/5） and 80%（4/5）， respectively， and they were completely sensitive to other antibiotics.Conclusion This study showed that the detection rate of vomiting Bacillus cereus in pre-packaged pastries in Taizhou was 5.2%（5/97）， ST 26 was the main type， there were a variety of diarrhea-type virulence genes in the five vomiting Bacillus cereus strains.

Abstract:Objective To investigate the effect of combination of Ligusticum chuanxiong active substance ethyl ferulate （EFE） and aerobic exercise （AE） on cognitive function of rats with Alzheimer’s disease （AD）.Methods Seventy SD rats were randomly divided into 5 groups （Control group， Model group， AE group， EFE group and AE+EFE group n=12）. The rat model of AD was induced by injecting β-amyloid 1-42 （Aβ1-42） into the hippocampus of rats on both sides. One week after modeling， the rats in AE group and AE+EFE group took aerobic treadmill exercise， while the other groups did not exercise. And the rats in EFE group and AE+EFE group were gavaged with 2 mL 100 mg/kg ethyl ferulate， the rats in other groups were gavaged with 2 mL 0.5% sodium carboxymethyl cellulose. All groups were treated for 6 weeks. After administration， the rats’ cognitive function was assessed by the Morris Water maze test. The levels of superoxide dismutase （SOD）， catalase （CAT） and malondialdehyde （MDA） in hippocampal tissue were detected according to the instructions of the kit. Hippocampal β-amyloid precursor protein lyase 1 （BACE1）， tumor necrosis factor-α （TNF-α）， interleukin-1β （IL-1β）， interleukin-6 （IL-6）， nuclear factor erythrocyte 2-associated factor 2 （Nrf2）， Kelch-like ECH-associated protein 1 （Keap1） and heme oxygenase 1 （HO-1） transcription levels were detected by qRT-PCR. The expression levels of BACE1 and Aβ1-42 in hippocampus were detected by western blot.Results Compared with AE group and EFE group， the escape latency of AE+EFE group decreased， and the number of crossing the platform within 60 s increased significantly （P<0.05）. Compared with AE group and EFE group， SOD and CAT levels in the hippocampus of AE+EFE group increased， while MDA levels in the hippocampus decreased significantly （P<0.05）. Compared with AE and EFE groups， the mRNA relative expressions of TNF-α， IL-1β and IL-6 in hippocampus of AE+EFE group decreased significantly （P<0.05）. Compared with AE and EFE groups， the relative expression levels of Nrf2 and HO-1 mRNA in the hippocampus of AE+EFE group were increased， while the relative expression levels of Keap1 mRNA decreased significantly （P<0.05）. Compared with AE and EFE groups， the relative expressions of BACE1 mRNA， BACE1 protein and Aβ1-42 protein in the hippocampus of AE+EFE group decreased significantly （P<0.05）.Conclusion Ethyl ferulate combined with aerobic exercise can effectively improve the cognitive function of AD rats， and the mechanism may be related to the inhibition of oxidative stress， inflammation and accumulation of Aβ.

Abstract:Objective To prepare reference materials of total mercury and methyl mercury in Agaricus blazei murill.Methods Agaricus blazei murill with suitable content of total mercury and methylmercury were screening from markets. After drying， grinding， screening， homogenized and packed， the reference materials were obtained. After homogeneity and stability tests， coordinated values were determined by seven laboratories， and the uncertainties were evaluated.Results The characteristic value of total mercury was 0.586 mg/kg， and the expanded uncertainty was 0.026 mg/kg. The characteristic value of methylmercury was 0.022 7 mg/kg， and the expanded uncertainty was 0.001 5 mg/kg.Conclusion The reference material has good stability， can be used for traceability and quality control of analyzing.

Abstract:Objective To investigate the pollution levels of algal health products in China， the liquid chromatography-mass spectrometry method based on AQC derivation for BMAA and its isomers in algal health products was established.Methods The samples were treated by acid hydrolysis， nitrogen concentration and AQC derivatization， and then analyzed by ultra-performance liquid chromatography-tandem mass spectrometry， quantified by internal standard methods of two commercial isotope standards.Results In the linear range of 0.25-100 μg/L， the correlation coefficients of BMAA toxins were all above 0.998. When the samples were 15 mg and the volume were 20.0 mL， the detection limits of BMAA， AEG and DAB were 133， 133 and 200 μg/kg， respectively. And the quantitative limits were 443， 443 and 667 μg/kg， respectively. The recoveries were between 86.7% and 126.0%， with the relative standard deviations between 1.1% and 14.0%. The detection rate for DAB was the highest in all samples （86%）， followed by AEG （23%） and BMAA （14%）. The concentrations of DAB， AEG and BMAA in the detectable samples were between 385-2 305， 250-518 and 472-698 μg/kg， respectively.Conclusion The established method based on AQC derivation LC-MS/MS method is more efficient and accurate. The levels of BMAA toxins in domestic algae health products were relatively high， it should be paid more attention and to strengthen the supervision.

Abstract:Objective To establish a culture-dependent rapid detection method for gas-producing spoilage bacteria in vinegar.Methods One kind of medium was screened out from six candidate media and modified. Then its specificity， accuracy， and sensitivity were determined， on which a detection method was proposed. This method was subsequently applied to assess heat sterilization conditions and preservative concentrations for vinegar products and to verify the detection effectiveness of vinegar products.Results A modified MRS medium that could specifically detect gas-producing spoilage bacteria in vinegar samples was proposed， with which negative results were obtained targeting at other 12 spoilage bacteria isolated from vinegar. The established method was adopted to examine 75 unknown vinegar samples and plastic bottle incubation method was used as control. Consistent results were obtained using both methods， however the detection rate of established method was 3-5 times faster than control， with a detection limit （initial bacterial count） ranging from 1 CFU to 10 CFU. The larger bacterial load is， the shorter detection time would be. And it will take only 1-2 d for high-contamination vinegar samples. Results also showed that sterilization at 75-85 ℃ for 5-15 min could effectively kill the gas-producing spoilage bacteria that is recalcitrant to common preservatives within their maximum allowable concentrations. The verification was in agreement with the actual situation.Conclusion The constructed method features fast， specific， accurate， and sensitive. This study sheds light on detection and comprehensive control of gas-producing spoilage bacteria for vinegar enterprises.

Abstract:Objective A method of ultra performance liquid chromatography-mass spectrometry （UPLC-MS） was established for the determination of octylphenol ethoxylates （OPEO） and nonylphenol ethoxylates （NPEO） in coating agent.Methods Samples were extracted with water， and purified by solid phase extraction column. And Thermo Acclaim RSLC 120 C₁₈ （2.1 mm×100 mm， 2.2 μm） chromatographic column was used for separation. Acetonitrile and 0.1% formic acid water were mobile phase， gradient elution and quantification was performed in SIM mode with positive ion mode of electrospray ionization.Results Octylphenol ethoxylates （OPEO） and nonylphenol ethoxylates （NPEO） were in the range of 0-400 μg/L， and the linear relationships was good （r²>0.996）. The recoveries at three spiked levels （0.12， 0.24 mg/kg， 1.2 mg/kg） were 88.5%-96.9% with the relative standard deviation of 2.9%-7.0%， and the limits of quantitative was 0.12 mg/kg.Conclusion The method was simple， rapid and accurate. Its sensitivity， accuracy and precision were suitable for the quantitative analysis and determination of alkylphenol ethoxylates in coating agent.

Abstract:Objective To investigate and analyse a foodborne disease outbreak caused by food contaminated with Salmonella typhimurium at a rural home-hosted banquet， and to provide a basis for the management of similar incidents in the future.Methods Data analysis on the outbreak of foodborne diseases caused by Salmonella typhimurium at a rural self-run banquet in Yaodu District， Linfen City， Shanxi Province in April 2019.Results A total of 41 cases were searched and the incidence rate was 14.64% （41/280）. The main clinical manifestations were abdominal pain （95.12%）， diarrhea （92.68%）， nausea （34.15%） and dizziness （31.71%）. The epidemic curve showed point source exposure， case-control and single-factor analysis showed that cold pork head meat （OR=3.85，95% CI：1.52-9.75） was suspected food. Salmonella typhimurium was detected in the stool sample of the three patients， which was consistent with the clinical symptoms and incubation period of the patients.Conclusion This was an outbreak of foodborne illness caused by the consumption of pork head meat contaminated with Salmonella typhimurium.

Abstract:Objective To analyze the main causes and sources of contamination， the continuous monitoring of Burkholderia gladioli contamination in the whole process of fresh wet rice noodles production and sales was monitored.Methods Three rice noodle production enterprises were selected and all raw materials， semi-finished products， finished products and environmental samples were collected according to the process. Strain identification and cluster analysis were performed according to GB 4789.29—2020 combined with VITEK 2 COMPACT biochemical detection， PCR， and MALDI-TOF MS techniques. The bongkrekic acid in food samples， environmental samples， the enrichment fluid and venom were detected by LC-MS/MS.Results Burkholderia gladioli was separated and identified in 22 food samples with a detection rate of 31.9% （22/69）. After toxigenic culture， 10 strains produced bongkrekic acid. Among 67 environmental samples， only one Burkholderia gladioli toxic strain was isolated from the inner surface sample of the rice slurry pipeline. The samples with the top three detection rate were 71.4% （10/14） of rice， 66.7% （2/3） of soaked rice and 50% （6/12） of selling products. According to the regional distribution of positive samples， the raw material storage area accounted for 43.5% （10/23）， sales place for 26.1% （6/23），raw material processing area for 21.7% （5/23）， finished product packing area for 8.7% （2/23）， and no positive samples were detected in hot-cure molding area. The cluster analysis showed that positive strain from the rice slurry pipeline were highly homologous to the strains from the same batch of rice slurry.Conclusion Rice may be the source of contamination in fresh wet rice noodles products enterprises. Open packaging and room temperature storage and transportation of products may be important reasons for cross-contamination， reproduction and toxicogenesis of Burkholderia gladioli. The raw materials should be separated from other production workshops to prevent the secondary pollution of the finished products. The cleaning and disinfection of the production and sales sites should be strengthened to effectively prevent and control the risk of Burkholderia gladioli contamination.

Abstract:Objective To investigate the contamination characteristics of common foodborne pathogens in raw livestock meat in the Chinese mainland market.Methods In 2021， a total of 4 734 samples of raw livestock meat were collected from 31 provinces （autonomous regions/municipalities） and Xinjiang Construction Corps， and qualitative tests were conducted for Salmonella， Listeria monocytogenes （L. monocytogenes）， diarrheagenic Escherichia coli （DEC） and Yersinia enterocolitica according to the national standard method of food safety.Results Salmonella had the highest detection rate with 12.10% （573/4 734）， followed by L. monocytogenes， which is 9.51% （450/4 734）， the detection ratio of DEC and Yersinia enterocolitica was 6.36% （301/4 734） and 2.18% （103/4 734） respectively. The detection rates of Salmonella and DEC in pork were 19.86% and 8.37%， respectively， higher than those of beef and mutton （about 4%）. There were differences in the detection of pathogenic bacteria in raw livestock meat under different preservation conditions. The detection rates of L. monocytogenes and Yersinia enterocolitis in chilled and frozen meat were higher than those in fresh meat. Salmonella and DEC had the highest detection rates in fresh meat. The positive rates of Salmonella and DEC in fresh meat in the second and third quarters were higher than those in the first and fourth quarters. The detection rates of Salmonella and DEC in bulk raw livestock meat were higher than those in pre-packaged products. The detection rates of Salmonella and L. monocytogenes were higher in the south China than those in the north China. The detection rate of DEC in the north was higher than that in the south. A total of 573 strains of Salmonella were isolated from raw livestock meat. The top 5 serotypes and their proportions in descending order were S. typhimurium 19.90%， S. derby 12.57%， S. london 12.22%， S. rissen 10.12% and S. enteritidis 2.97%.Conclusion The detection rate of pathogenic bacteria in raw livestock meat is high， especially the contamination of L. monocytogenes in frozen and chilled livestock meat and Salmonella in fresh livestock meat in the second and third quarters are serious， which should be taken as the focus of monitoring in the future. Enterprises and consumers should pay attention to preventing the possible risk of disease caused by incomplete heating and cross-contamination of raw and cooked animals.

Abstract:Objective To study the combined use of preservatives in food in China and to evaluate the intake level of common preservatives and their cumulative exposure risk.Methods The exposures of common preservatives were calculated by simple distribution assessment method based on the maximum allowable usage of preservatives of National Food Safety Standards the Use of Food Additives GB 2760—2014 and consumption data from the fifth Chinese Total Diet Study. The cumulative exposure risk was evaluated by the hazard index method （HI） based on the combined use of preservatives in Chinese food in the global new product database， the exposures and acceptable daily intake （ADI） of preservatives.Results 43.36% of foods that use preservatives in China use two or more preservatives， the highest utilization rate is binary combination （31.78%）， with a maximum of 6 combinations. Consider only the population exposure risk of one preservative alone， the daily average exposure in the diet of the general population and the high food consumption group （P95） in sodium benzoate， potassium sorbate and sodium diacetate were lower than their corresponding ADI. The daily average exposure in the diet of the general population in nisin， sodium nitrate and sodium dehydroacetate were lower than their corresponding ADI， but the high food consumption group （P95） were higher than their corresponding ADI. Cumulative assessment shows that the average exposure of the most common binary and ternary preservative combinations in the general population has an HI of less than 1， but the mean value of HI of the most common quaternary and quintuple and the P95 of HI of binary， ternary， quaternary and quintuple preservative combinations in the general population has an HI of greater than 1. Cumulative assessment shows that the preservatives of common preservative combinations are used alone， and some individuals have the problem of excessive intake， but if used in combination， there may be 1.47~1.75 times the health risks of individuals.Conclusion Food preservatives are often used in combination in China. The cumulative exposure risk of the most common binary， ternary， quaternary， and quintuple preservative combinations has gradually increased. Cumulative assessment shows that the use of the most quaternary and quintuple preservative combinations has created health risks for some people， and practical usage of these preservatives should be monitored and more accurately evaluated. When the food additives with the same anticorrosive function are mixed， each of which accounted for the maximum use of their dosage should not exceed 1.

Abstract:To strengthen the construction of food inspection team and ensure food safety， the legislation， system and personnel of food inspector in the United States， Canada and the European Union was systematically investigated， and the general rules， common characteristics and experience of food inspector management systems in relevant countries （regions） was summarized. There are many measurement， including sufficient legal basis， clear responsibilities， obvious characteristics of full-time and standardized management in the inspector team， relatively independent with clear responsibilities in inspection institutions， rich inspection tools， attaching importance to information disclosure internal mechanism to supervise and inspect the quality， paying attention to training， unified assessment standards， putting forward policy suggestions， and so on. Based on China’s reality， it is suggested to improve legislation to empower inspectors， implement graded and classified management， strengthen the construction of national food inspection team and inspector teachers， attach importance to practice and design training courses scientifically， research and development of inspection tools， and so on， which can strengthen the professional construction of China’s food inspection team to provide reference.

Abstract:Objective To comprehend the epidemiological and molecular characteristics of diarrheagenic Escherichia coli （DEC） in a specific district of Beijing City from 2018 to 2022， aiming to provide evidence for the prevention and control of related diseases.Methods Stool specimens of 1 600 diarrhea cases were collected from 3 surveillance sentinel hospitals in one district of Beijing from 2018 to 2022， and DEC strains were isolated from the specimens. The virulence genes were detected by multiplex PCR， and the pathogenic types were obtained. The epidemiological and clinical data were analyzed. Simultaneously， pulsed-field gel electrophoresis （PFGE） was used to ascertain the molecular types of the strains. Cluster analysis was performed on the fingerprints of ETEC， EPEC， and EAEC strains.Results DEC strains were isolated in 144 of 1 600 specimens from one district of Beijing from 2018 to 2022， with a detection rate of 9.00% （144/1 600）. The primary pathogenic type was ETEC， followed by EPEC， EAEC， and EHEC， no EIEC cases were detected. The male-to-female ratio of DEC infection cases was 1.48∶1， with the highest detection rate occurring in the 31~45 age group （11.15%， 59/529）. The year 2019 exhibited the highest positive detection rate of DEC， with the highest rates consistently observed during the summer months. Significant differences in the positive detection rate of DEC were observed among different age groups and years. Most of the DEC-positive patients suffered diarrhea， dehydration， abdominal pain and watery stool. The 144 DEC strains yielded 111 bands， with homology ranging from 13.07% to 100.00%. Isolates of the same type ranged from 2 to 7 strains， and their separation intervals varied from the same day to several years.Conclusion ETEC and EPEC were the predominant pathogenic types of DEC in this area， while EHEC infections persisted. DEC exhibited a high incidence during the summer and was more frequently detected in young adults. The PFGE bands exhibited a highly polymorphic distribution.

Abstract:Objective To characterize the pathogenic characteristics and homology of Staphylococcus aureus （SA） isolated from a foodborne outbreak.Methods A selection medium was applied to culture the possible infectious agent according to national standard methods， and the micro broth dilution method was applied to determined the isolate’s sensitivity to 16 drugs. Whole genome sequencing and bioinformatics analysis were employed to investigate the isolates’ molecular genetic characteristics and homology.Results A total of 16 SA strains were isolated in this outbreak， including eight strains isolated from patients， one from the kitchen worker， and seven from food. MLST and Spa typing analysis identified five distinct types in this outbreak， namely ST7-t91， ST5-t548， ST398-t588 and ST965-t62， in which the ST7-t91 and ST5-t548 types account for strains from humans； All ST7 isolates were resistant to tetracycline and penicillin， carrying resistance genes aadD， tet （K）， blaZ， and lnu （A） respectively， while the ST5 strain was sensitive to all tested antibiotics； cgMLST analysis revealed that the difference of these ST7 strains was less than three loci. Gene annotation revealed that ST7 strains contained the sea， chp， scn， and sak virulence genes， while ST5 possessed chp， scn， sak， seg， selk， selm， selo， and seln genes.Conclusion This outbreak was caused by mixed infections of multiple ST types of SA， with ST7-t91 as the predominant type， and this clone present a high pathogenicity and was sensitive to somefirst-line clinical antibiotics tested，such as cephalosporins and quinolones.

Abstract:Objective To analyze the content of 6 kinds of amatoxins in 3 species of Lepiota collected from Chuxiong of Yunnan Province.Methods The collected mushrooms were baked and dried at 45 ℃， and species identification was carried out by morphological and molecular biology methods. The mushrooms were divided into three different growth periods （growth period， mature stage， aged stage） and different tissue parts （pileus， stipe， whole）， and the toxins were extracted by ultrapure water ultrasound. The determination was performed by ultra-performance liquid chromatography-triple quadrupole tandem mass spectrometry with electrospray （ESI^-） in multiple-reaction monitoring （MRM） mode， and the content was quantitatively analyzed by external standard method.Results No amatoxins were detected in Lepiota clypeolaria and Lepiota cristata， while α-amanitin and β-amanitin were detected in Lepiota brunneoincarnata， and the content of α-amanitin was higher than β-amanitin. The total content of α-amanitin was highest in the mature stage （1.67 mg/g）， followed by the grow stage （1.56 mg/g） and least in the aged stage （0.40 mg/g）. And the total content of β-amanitin was also highest in the mature stage （0.71 mg/g）， followed by the growth stage （0.60 mg/g） and lowest in the aged stage （0.14 mg/g）. The cap part was richer in α-amanitin and β-amanitin than the stipe part in the growth and mature stages， while the content of α-amanitin and β-amanitin in the aged stage was higher in the stipe than in the pileus.Conclusion In Chuxiong Prefecture， Yunnan Province， the flesh-brown ring-stalk mushroom L. brunneoincarnata mainly contains Amatoxins， including α-AMA， β-AMA， Amanin， and Amaninamide， excluding phalloidin and virotoxin. The content of α-AMA and β-AMA varies in different growth periods and tissues， providing reference for the clinical diagnosis and treatment of poisoning by this type of mushroom.

Abstract:High content analysis combines automated microscopy and quantitative image analysis to visualize in vitro models for multi-parameter analysis， which has the advantages of high efficiency， rapidity and multi-targeting， and it has been applied in the field of in vitro toxicology research. Food toxicology， as a branch of toxicology， plays an important role in safeguarding food safety and human health. Traditional experiments can hardly meet the current rapidly increasing demand for safety evaluation of various food-related risk substances， for which high content analysis provides an efficient technical approach. Recent applications of high content analysis in the field of food toxicology would be reviewed in this article， in order to provide reference for food safety assessment methods and technological innovation.

Abstract:The European Union（EU）， as an important target market for the export of the agro-products of China， always keeps a relatively high food safety protection level， strict pesticide management policy and low tolerance to pesticide residue.In recent years， there is an increasing trend that the agro-products of China are hindered during their export to the EU due to pesticide residue problems， as a result of the higher requirements for agro-product import further raised by the EU. Brought by its greater effort to promote the strategy of sustainable agricultural development， the EU has continuously tightened its policy on the registration and use of pesticides and its maximum residue limit of multiple pesticides.Based on the export violation data of China agro-products notified by RASFF from 2012 to 2022， this article sorts through and analyzes the current situation and reasons of Chinese agro-products being hindered from exporting to EU because of pesticide residues， aiming at providing a reference to grasp the trend of EU trade barriers to pesticide residues and improving the foresight and initiative in dealing with EU technical barriers to trade of agro-products.