Abstract:Hydrolyzed milk proteins include hydrolyzed whey protein and hydrolyzed casein. Hydrolyzed whey protein can be divided into partial （moderate） hydrolyzed whey protein and extensive hydrolyzed whey protein. Hydrolyzed milk protein is used as raw material in infant formula for special medical purpose in China， while partially hydrolyzed milk protein can be used as raw material for standard infant formula in Europe， America， Australia， New Zealand， Japan and Korea. Extensively hydrolyzed milk protein can only be used as raw material for special medical use formula food. The quality of different types of hydrolyzed milk protein ingredients provided by different manufacturers varies a lot. And there is no one-to-one correspondence between their physiological effects related to allergy and gastrointestinal symptoms in healthy infants and infants with high allergy risk. This article reviews the progress of research and regulatory management of hydrolyzed milk protein infant formula powder on allergy and functional gastrointestinal disorders of infants and toddlers.

Abstract:Objective To measure perfluoroalkyl and polyfluoroalkyl substances （PFASs） in cord blood of newborns in Henan province and explore influencing factors of PFASs exposure.Methods The present study was based on the birth cohort established in Henan Province from 2013 to 2015. The levels of 11 PFASs in cord blood samples （n＝336） were detected. Generalized linear regression was used to analyze the effects of maternal socio-demographic characteristics， life style and dietary intake on the level of PFASs in umbilical blood of newborns.Results The newborns of older mothers （GM ratio 1.03-1.05）， higher average monthly family income （GM ratio 1.30-1.63）， pregnancy smoking （GM ratio 2.90， 95% CI：1.11， 7.56） and passive smoking （GM ratio 1.84， 95%CI： 1.02， 3.32） tend to show higher PFAS exposure in cord blood. Newborns whose mothers worked during pregnancy （GM ratio 0.82， 95%CI：0.67，1.00）， and with multiparous mothers （GM ratio 0.65， 95% CI： 0.51， 0.82） had lower concentrations of PFASs. Mothers who had higher intake frequency of beef or mutton， pumpkin， garlic seedlings and pickles during pregnancy tend to have increased concentrations of PFASs in cord blood （GM ratio was 1.33-1.80）， while the concentration was lower during mothers who consumed more oranges， milk， cabbage and eggplant during pregnancy （GM ratio was 0.68-0.82）.Conclusion Maternal age， family income， history of smoke and passively smoke during pregnancy， parity， frequency of beef or mutton， and plant-based foods intake may affect PFASs exposure of newborns.

Abstract:Objective To develop plasmid DNA reference materials that can be used for polymyxin antibiotic resistance encoding genes rapid detection.Methods The reference sequence of mcr-1， mcr-3 and mcr-5 were retrieved from the National Center for Biotechnology Information to construct recombinant plasmids and strains. The recombinant strains were subcultured for 15 generations to detect the genetic stability of the target gene. The recombinant plasmid was extracted and vacuum dried to prepare the standard sample. The limit of detection （LOD） of PCR and RT-qPCR was determined after the standard sample was hydrated and continuously diluted with 10-fold gradient， respectively. Multi-tube plasmid DNA standard samples were randomly selected to qualitatively and quantitatively evaluate the uniformity and storage stability at 4 ℃， 37 ℃ and -20 ℃ by PCR and UV spectrophotometer.Results Fragments of mcr-1， mcr-3 and mcr-5 that encoding polymyxin resistance mechanism were successfully obtained. Target genes in the recombinant strains could stably inherited after subcultured for 15 generations. The LOD of PCR and RT-qPCR of mcr-1， mcr-3 and mcr-5 standard samples were 1.67×10⁴ and 1.67 copies/μL， 1.31×10⁴ and 13.1 copies/μL， 1.55×10⁵ and 1.55 copies/μL， respectively. The mass F values of 12 standard samples randomly selected for each gene were all less than the F critical value， each gene could be detected by RT-qPCR and indicating that the uniformity of the samples met the requirements. When standard samples were stored at 4 ℃ for 90 d， 37 ℃ for 14 d and -20 ℃ for 360 d， the qualitative and quantitative test result showed it was stable without significant difference.Conclusion In this study， plasmid DNA standard samples that carrying mcr-1， mcr-3 and mcr-5 were prepared. The target genes could be stably inherited， the standard samples had good uniformity and storage stability， and could be used as a quality control samples for polymyxin antibiotics resistance encoding genes detection and mechanisms prediction.

Abstract:Objective To investigate the contamination characteristic， antibiotic resistance phenotype and genotype of Escherichia coli （E.coli） in raw chicken and raw pork in Beijing.Methods A total of 259 meat samples （91 pork and 168 chicken） were randomly collected from large and small supermarkets and farmer’s markets in various regions of Beijing. E.coli was isolated after enrichment. The isolated strains were identified by MALDI-TOF/MS and 16 s rRNA sequencing. The Gram-negative bacteria drug sensitivity plate was used for the antimicrobial susceptibility test of the isolated strains， and the whole genome was sequenced to analyze the antibiotic-resistant genotypes.Results 169 strains of E.coli were isolated from 259 samples， with a detection rate was 65.25%， among which the detection rates of E.coli in chicken and pork were 77.38% and 42.86% respectively. The result of antibiotic susceptibility test showed that E.coli was highly resistant to trimethoprim-sulfamethoxazole （83.33% in chicken and 91.67% in pork）， followed by doxycycline （32.35% in chicken and 38.89% in pork）. Meanwhile， they also showed different degrees of antibiotic resistance against gentamicin， tobramycin， cefotaxime and colistin. Genotyping analysis found that β-lactam genes ampC1 and ampC2 had the highest carrying rate of 93.10% and 98.28%， respectively. In addition， multidrug resistance genotypes such as ESBL， NDM-1 and mcr-1 were also detected， among which bla_TEM-1D and blaCTX-M_-9 were the main ESBL resistance genes.Conclusion At present， there is a serious E.coli contamination in raw meat in Beijing， especially in chicken. The isolated strains not only showed complex antibiotic-resistance phenotypes， but also carried a variety of antibiotic-resistance genotypes. The control of microbial contamination and bacterial drug resistance in fresh meat samples should be strengthened， especially ESBL-producing Escherichia coli， which provided a scientific basis for the prevention and control of foodborne diseases.

Abstract:Objective To explore the effect of Erythronium sibiricum bulb polysaccharides on asthma and its mechanism based on oxidative stress.Methods Fifty female BALB/c mice were randomly divided into the negative control group， asthma model group， dexamethasone group， low and high-dose Erythronium sibiricum bulb polysaccharides groups. Except the negative control group， the asthma model was established by sensitizing with chicken egg albumin （OVA）. The number and classification of inflammatory cells in bronchoalveolar lavage fluid （BALF） were determined by a whole blood analyzer. Hematoxylin-eosin （HE）， Periodate acid-Schiff （PAS） and Masson staining were used to observe the lung pathology of asthmatic mice. The contents of malondialdehyde （MDA） and the activity of superoxide dismutase （SOD） in serum were detected by colorimetry. Determination of protein expression and mRNA abundance of nuclear factor erythroid2-related factor 2（Nrf2）， HemeoxygenasE1 （HO-1） and Vascular endothelial growth factor （VEGF） in the lung were detected by immunohistochemistry and real-time fluorescence determination polymerase chain reaction （RT-PCR）.Results Compared with the negative control group， the numbers of total inflammatory cells， neutrophils， monocytes and eosinophils in the BALF of the model group were significantly increased （P<0.05）， as well as the inflammatory infiltration of lung tissue was obvious. Meanwhile， the collagen deposition and mucus secretion increased along with the hyperplasia of the cup cell. The MDA content was increased （P<0.05） while the SOD activity was inhibited （P<0.05） in the serum of asthmatic mice. The protein expression and mRNA abundance of Nrf2， HO-1 and VEGF in lung tissues were increased （P<0.05） in the model group. Compared with the model group， after administration of Erythronium sibiricum bulb polysaccharides， the results of inflammatory cell classification and counting indicated that the total number of inflammatory cells， neutrophils， monocytes and eosinophils were significantly decreased （P<0.05）， and the pathological lung conditions were improved. The protein expression levels and mRNA abundance of Nrf2 and HO-1 in lung tissues were increased （P<0.05） while the protein expression and mRNA abundance of VEGF were significantly down-regulated （P<0.05） compared to the model group.Conclusion Erythronium sibiricum bulb polysaccharides can relieve airway inflammation and airway remodeling in asthma， which may take effect by activating the Nrf2/HO-1 pathway and inhibiting the expression of VEGF.

Abstract:Objective In order to achieve the authenticity and quality identification of rice bean processed food, qualitative real-time fluorescent polymerase chain reaction (PCR) and quantitive droplet digital PCR (ddPCR) methods were established for adzuki bean ingredients misused or mixed in rice bean processed food.Methods Specific primers and probes for qualitative real-time fluorescent PCR were designed according to their conserved sequences in genomic DNA, as well as universal primers and probe for quantification of adzuki bean ingredient in rice bean processed foods using duplex droplet digital PCR. Then a linear formula of mass ratio-DNA copy was established.Results The LODs of real-time fluorescent PCR for rice bean and adzuki bean were 0.1 and 0.01ng/μL separately, and the LOQs of ddPCR for both were 6 copies/μL. Accurate quantification of adzuki bean ingredient with a mass ratio from 5% to 80% in rice bean processed foods therefore could be achieved.Conclusion This method could be used for qualitative and mass ratio quantification determination of adzuki bean ingredients in rice bean processed food.

Abstract:In the Post-COVID-19 era， people have higher and more urgent requirements for food safety， such as control of microbial hazards and chemical contaminant hazards in food， food quality including nutritional properties. In this context， low-temperature technologies has been explored in the food industry and low-temperature plasma has raised high attention in the filed including physics research， food sciences and the food industry. Low-temperature plasma is the fourth state of matter after solid， liquid， and gaseous states. The active chemical substances produced by plasma can quickly kill microorganisms and degrade mycotoxins at ambient temperature without leaving any known chemical residues. In food processing， the application of low-temperature plasma technology can improve product safety and extend shelf life， degrade mycotoxins and reduce their toxicity. This review presents an overview of the action of cold plasma against molds and mycotoxins， improvement of food characteristics， and the underlying mechanisms， so as to provide a reference of plasma technology for ensuring food safety and quality.

Abstract:Objective To establish a method for simultaneous determination of 11 aminoglycosides antibiotics （spectinomycin， dihydrostreptomycin， hygromycin B， streptomycin， gentamicin C1， amikacin， gentamicin C2， kanamycin， gentamicin C1a， tobramycin and apramycin） in liquid milk and milk powder samples by high performance liquid chromatography tandem mass spectrometry （HPLC-MS/MS）.Methods The dairy products were extracted by water containing 1% acetic acid， concentrated and purified by the immunoaffinity cartridges， and then analyzed by HPLC-MS/MS. A BEH Amide column was used for the separation of target drugs as well as acetonitrile and water containing 0.5% formic aid used as the mobile phase. Matrix matched calibration was applied in the quantitation.Results The calibration curves achieved good linearity in the range of 5-500 μg/L with the correlation coefficients （r） greater than 0.99； the quantification limits of AGs in liquid milk and powder were 3 and 10 μg/kg， respectively. The average recovery ranged from 65.12% to 105.95% with relative standard deviations （RSD） ranged from 0.85% to 19.12%.Conclusion This method presented good selectivity， high sensitivity and simple operation， which was suitable for the determination of 11 aminoglycoside antibiotics in dairy products.

Abstract:Objective A method was developed for the simultaneous determination of nine novel brominated fire retardants （NBFRs） in milk by atmospheric pressure gas chromatography-tandem mass spectrometry （APGC-MS/MS）， and the extraction solvent and clean-up method were optimized.Methods The freeze-dried milk samples were extracted by hexane/dichloromethane （1∶1， V/V）， cleaned up by GPC and further degreased by sulfuric acid， and then analyzed by Multi-selected reaction monitoring（MRM） mode.Results The result showed that there were good linear relationships for the target compounds in a certain concentration range， with their correlation coefficients （R²） no less than 0.99. The limits of detection and the limits of quantification （LOQs） were 0.000 2-0.098 4 μg/L （fw） and 0.000 5-0.295 2 μg/L （fw）， respectively. The spiked recoveries were 73.94%-116.98% with RSD not more than 19.30% using blank milk. The method has been successfully applied to 22 milk samples. Among them， PBT， PBEB， EH-TBB， BTBPE and DBDPE were the major contaminants with the detection rates of 86.36%， 100.00%， 54.55%， 50.00% and 54.55%， respectively. The concentrations were 0.001-0.20 μg/L （fw）， < LOQ-0.06 μg/L （fw）， < LOQ-0.11 μg/L （fw） and < LOQ-0.85 μg/L （fw）， respectively.Conclusion The method was sensitive， precise and accurate， and can be used for the simultaneous determination of 9 NBFRs in milk.

Abstract:Objective To establish a method for determination of 12 polar pesticide residues in vegetables and fruits by supercritical fluid chromatography-Q-Orbitrap （SFC-Q-Orbitrap）.Methods The samples were extracted with 1% acidified methanol，and the extract was purified by dispersed solid phase extraction， separated by ultra silica column （150 mm× 2.1 mm， 3 μm） and obelisc r column （150 mm× 2.1 mm， 5 μm）， determined by SFC-Q-Orbitrap， scanned by segmented mixed product ions， and quantified by isotope internal standard calibration curve.Results The calibration curves for 12 pesticides exhibited good linearity in the range of 20.0-500 μg/L， with the correlation coefficients（R²） above 0.997. The average recoveries at 0.05 and 0.20 mg/kg spiked levels were in the range of 80.2%-120% and the relative standard deviations （RSD，n＝6） were in the range of 2.14%-14.6%. The limits of detection and the limits of quantification were 0.010 1-0.016 2 mg/kg and 0.050 mg/kg.Conclusion The method has the advantages of simple operation， accurate quantification and high efficiency. It can meet the requirements determination of high polar pesticide residues in vegetables and fruits.

Abstract:Objective To establish an analytical method for 9 mushroom toxins in wild fungus by liquid chromatography-tandem mass spectrometry （LC-MS/MS） including 5 acute liver failure toxins （α-amanitin， β-amanitin， γ-amanitin， phallacidin and phalloidin） and 4 psycho-neurological disorder toxins （ibotenic acid， musimol， muscarine and psilocybin）.Methods The dried sample was extracted with 50%（V/V）methanol /water mixture containing 0.5%（V/V）formic acid， protein was precipitated with acetonitrile and diluted with water. The toxins were separated with XBridge^TM BEH C₁₈ column （150 mm×3.0 mm， 2.5 μm）， gradient eluted with the mobile phase of 0.005%（V/V） formic acid aqueous solution–methanol， and measured by MS/MS with multiple reaction monitoring （MRM） mode.Results The conditions of sample extraction， dilution ratio and chromatographic separation were optimized. 9 mushroom toxins in different wild fungus could be qualitatively and quantitatively measured based on the pure solvent standard calibration. The limits of detection （LODs） and quantification （LOQs） in sample matrix were 6-15 mg/kg and 20-50 mg/kg， respectively. The linear ranges were 0.004-2 mg/L with correlation coefficients （r） of between 0.9973-0.9995. The average recoveries at three spiking levels （50 mg/kg， 500 mg/kg and 5000 mg/kg） were 78.6%-109.7% with relative standard deviations （RSDs） of 2.7%-9.0%. The toxin compositions and contents varied greatly in the wild mushrooms sampled in some poisoning cases.Conclusion The method is simple， rapid and accurate. It has been applied to the analysis of mushroom toxins in common poisonous wild mushrooms and the disposal of poisoning emergencies. It can provide rapid and accurate technical support for the etiology identification of poisoning cases and the timely rescue of patients.

Abstract:Objective To prepare and evaluate Enterotoxigenic Escherichia coli（ETEC） reference.Methods The standard strain CMCC（B）43208 was identified by biochemical reaction， matrix-assisted laser desorption ionization time of flight mass spectrometry （MALDI-TOF MS） and gene sequencing. 600 ETEC reference samples with 10³ CFU/sample were prepared by freeze-drying. 20 samples were selected randomly for uniformity test， and samples were tested transportation stability by simulating 25 and 37 ℃， and storage stability by stroing samples at -20 and 4 ℃. Three laboratories were organized for collaborative calibration. 20 kinds food were chosen as the substrates to evaluate the applicability. The strain CMCC（B）43208 was identified as Escherichia coli by all of biochemical reaction， MALDI-TOF MS and 16 s RNA gene sequencing， and was identified as ETEC by lt，stp and sth gene. The uniformity result was F=1.48 <F_INV（0.05， 19， 20）by one-way anova. The samples were still 10³ CFU/sample after storing 7 d at 25 and 37 ℃， 28 d at 4 ℃ and 60 d at -20 ℃. All the results of three laboratories were ETEC （10³CFU/sample）.Results All 20 food substrates presented ETEC positively when adding the ETEC samples， while substrates presened ETEC negtively with no samples adding， the standard strain CMCC（B）43208 was ETEC.Conclusion The prepared samples were uniformit and stable， and the results of the collaborative calibration and applicability evaluation achieved expected requirements as 10³ CFU/sample， so the samples can be used as ETEC reference.

Abstract:Objective A pretreatment method based on microwave extraction combined with liquid chromatography-inductively coupled plasma mass spectrometry （LC-ICPMS） was established to accurately determine the five arsenic speciations of arsenobetaine （AsB）， arsenite （As （Ⅲ））， dimethyl arsenate （DMA）， monomethyl arsenate （MMA） and arsenate （As （Ⅴ）） in infant rice flour.Methods The samples of infant rice flour were extracted with 1% HNO₃ and microwave extraction at 90 ℃ for 60 min， centrifuged through the membrane， and the extract was analyzed quantitatively by LC-ICPMS.Results The established method showed good linear relationships in the range of 0.1-50 μg/L with the coefficient of determination R²>0.999 9 for the five arsenic species. The recoveries at different spiked levels were 95.20%-102.00%， and the intra day and inter day precision was less than 5%. The limits of detection of the method were 0.006-0.012 mg/kg.Conclusion The microwave extraction pretreatment method was simple and fast， and the quantitative analysis was sensitive and accurate， which was suitable for the determination of arsenic species in infant rice flour samples.

Abstract:Objective The aim of this study was to investigate the contmaination status of pesticide residues in vegetables sold in Inner Mongolia， and provide experimental basis for vegetable production， supervision， standard revision and risk assessment.Methods 480 vegetable samples were collected from 12 cities in Inner Mongolia during 2019-2020， and 9 kinds of pesticide， 13 kinds of fungicide and dithiocarbamates were tested according to the procedure in the National Food Safety Surveillance Manual. Judgments were made in line with National Food Safety standard - Maximum Residue Limits for Pesticides in Food （GB 2763-2019）.Results In 480 vegetables， the detection rates of 9 kinds of pesticide， 13 kinds of fungicide and dithiocarbamates were 11.04%（53/480）， 34.79%（167/480） and 27.71%（133/480）. The violation rates were 3.33%（16/480）， 1.46%（7/480） and 2.29%（11/480）. The vegetables which violated the standard were celery， scallion， pak choi and spinach. There were multiple fungicide residues in single vegetable.Conclusion Pesticide residues and violation were detected in vegetables sold in Inner Mongolia and over standard， high toxic and virulent pesticides were detected. Effective supervision and inspection should be taken by related departments.

Abstract:Objective To investigate the source of infection and the pathogenesis of listeriosis monocytosis in a case of maternal listeriosis， and to provide evidence for the prevention and control of listeriosis.Methods Field epidemiological investigation was carried out to collect case information， blood samples of patients， food samples in refrigerators and kitchen environment of families， food samples from farm product markets near families were collected， and Listeria monocytogenes in samples from different sources were detected.Results Patient often ate Chinese cold dishes purchased from farm product markets （5~7 times a week）， and made Chinese cold dishes at home or cut again. The food stored in the refrigerator of his family was not cooked， and the raw fruit roted in the refrigerator. Of the kitchen two chopping board unripe did not divide， clean disinfect not in time， kitchen operating surface existed cross pollution. The results showed that a total of 3 strains of Listeria monocytogenes were isolated from the 11 samples， one from the patient’s blood sample and two from food smear and cutting board smear in the kitchen refrigerator. It was suggested that this case was caused by the consumption of contaminated food and infected the fetus through the placental barrier.Conclusion This case was the first successful attempt to trace the source of listeriosis monocytosis infection in food and environment in Fengtai District. Listeria monocytogenes were detected in the raw meat， carrots， and kitchen samples in the refrigerator of the patient’s family. It was clear that the cross-contamination of food and environment caused the infection of listeria monocytogenes in the patient. Early recognition and treatment in hospitalis was an important guarantee to avoid adverse outcomes in neonates.

Abstract:Objective To investigate the residues of quinolones，tetracyclines and metronidazole in chicken and egg samples in Hubei from 2016 to 2019.Methods A total of 373 chicken and 365 egg samples collected from 15 cities in Hubei Province were detected by ultra performance liquid chromatography tandem mass spectrometry.Result Antibiotics residues were detected in 65 chicken and 50 egg samples monitored from 2016 to 2019. The annual antibiotics detection rates in chicken were 9.76%（8/82）， 16.67%（16/96）， 38.14%（37/97）and 4.08%（4/98）， respectively. In egg samples， the detection rates were 15.00%（12/80），8.24%（7/85），24. 00%（24/100），7.14%（7/98）， respectively. There were significant differences in the annual detection rates of antibiotics in chicken and egg samples（P<0.001，P=0.002）. There was no statistical difference in the detection rate of antibiotics at different sampling sites （χ²=0.053， P=0.819）. Doxycycline， enrofloxacin，ciprofloxacin，ofloxacin，norflocaxin and other banned antibiotics were found in eggs，in addition， metronidazole were both detected in chicken and egg samples .Conclusion This study indicated that the exposure of quinolones in chicken were in the safe range，but some banned antibiotics in chickens and eggs might lead health risks to people.

Abstract:Objective To understand the contamination status and antibiotics resistance of Arcobacter isolated from commercial fresh whole chicken in Shunyi District.Methods Sixty fresh whole chicken from retail markets and supermarkets in Shunyi District were randomly purchased. The Bacterial isolation was carried out using the membrane filtration methods. The strains were identified by matrix-assisted laser desorption ionization-time of flight mass spectrometery and real-time fluorescent PCR. The mass spectra of the strains were clustered. The isolated Arcobacter strains were subjected to a susceptibility test for 11 antibiotics using agar dilution method.Results The detection rate of Arcobacter in 60 samples of commercially available fresh whole chicken was 26.67% （16/60） and all of them were Arcobacter butzleri. The detection rate of Arcobacter in June and July was significantly higher than that in May. Sixteen strains of Arcobacter were clustered by time-of-flight mass spectrometry and were divided into two clusters with a relative distance of 1 000. The relative distance was negatively correlated with the similarity of the strains， and the clustering map had a certain suggestive effect on the regional origin of the samples. The Arcobacter isolates were highly resistant to quinolone antibiotics and the resistance rates to nalidixic acid and ciprofloxacin were 81.25% and 43.75%， respectively. The resistance rate to gentamicin （12.50%） and erythromycin （12.50%）， azithromycin （12.50%）， telithromycin （12.50%） and streptomycin （6.25%） was relatively low.Conclusion The detection rate of Arcobacter in raw chickens in Shunyi District is high. It should be alert to the risk of food-borne diseases caused by undercooked cooking and cross-contamination.

Abstract:Objective To study the contamination level of mineral oil hydrocarbons in complementary foods for infants and young children and assess its potential health impact for consumers aged 0-3 years old in China.Methods The contents of mineral oil saturated hydrocarbons （MOSH） and mineral oil aromatic hydrocarbons （MOAH） were determined by on-line high-performance liquid chromatography coupled with gas chromatography and flame ionization detector. Based on the food consumption data of Chinese residents in 2015， the exposure to mineral oil hydrocarbons in complementary foods of Chinese infants and young children aged 0-3 years old was assessed by simple distribution method.Results The overall detection rate of MOSH （C16-C35） in 4 types of complementary foods （canned foods， rice flour， noodles， and biscuits or molar sticks） in total of 138 commercially available complementary food samples was 45.65%， and the mean contamination level in different types of complementary foods was in the range of 0.55-4.40 mg/kg. The MOAH was only detected in 1 sample of noodles and 4 samples of biscuits or molar sticks. The overall detection rate of MOAH was 3.62%. The average daily exposure and high food consumption （P95） daily exposure of MOSH （C16-C35） for complementary foods consumer only population were 6.21 and 19.27 μg/kg·BW， respectively. The margins of exposure of all age groups were higher than 100.Conclusion The health risk from dietary exposure to MOSH by consuming complementary foods is very low for infants and young children aged 0-3 years old in China. Attention should be paid to the contamination of MOAH in complementary foods for infants and young children.

Abstract:Objective To evaluate the chronic and acute exposure risk of the 13 commonly used pesticides in local tea samples in Guangdong Province， so as to provide the basis and technical support for production supervision and consumption， and provide data for the revision of maximum residue limits （MRLs）.Methods 110 local tea samples were collected from the year 2017—2020， and 13 pesticide residues were detected and quantified following the GB 23200.113-2018 method based on GC-MS/MS. Acute and chronic cumulative risk assessment were calculated using hazard index （HI） approach.Results 8 kinds of pesticides in 110 local tea samples were detected in which the detection rates and the residue levels of bifenthrin， fenpropathrin and cypermethrin were the highest. The cumulative chronic and acute exposure levels of bifenthrin， fenpropathrin and cypermethrin to tea intake of Guangdong residents were 4.87×10^-5 mg/（kg bw·d） and 4.79×10^-3 mg/（kg bw·d）， accounting for 89.09% and 86.01% of the total pesticide exposure， respectively. The chronic and acute exposure level of males were higher than females， and urban residents were higher than rural residents. For all the pesticides detected， their chronic and acute cumulative hazard indexes were 3.69×10^-3 and 4.66×10^-1， respectively， which indicated that the risk was low.Conclusion The chronic and acute dietary exposure risk of pesticide residues from local tea were both low， but pesticide residues in Guangdong province were common， so the application and management of pesicides in local tea should be further strengthened.

Abstract:Objective To evaluate the food exposure risk of ochratoxin A （OTA） in Zhejiang Province， China.Methods A representative of 518 samples （five food categories including 24 kinds of food stuffs） were examined from 2018 to 2019 in order to evaluate the occurrence of OTA in Zhejiang Province. Food consumption data was collected from the Food Consumption Survey of Zhejiang Province between 2015 and 2016.Results OTA was only detected in grains and related products， but was not detected in fruits， tea， puffed foods and infant cereals. The higher incidence was found in oats and related products （16.1%，5/31）； the OTA levels of positive samples ranged from 0.53 to 4.00 μg/kg； and the maxium value of 4.00 μg/kg was found in oats and related products； no samples exceeded the limit set by China （5 μg/kg）. Exposure assessment showed that in most consumption scenarios， OTA probable daily intake for eating grains and related products were 0.004-7.360 ng/kg BW， less than OTA safety exposure value of 14 ng/kg BW； the highest OTA exposure value was 19.627 ng/kg BW and represents 140.19% of the safe intake. The 1-6 years old age group had the highest daily intake of 0.014-34.644 ng/kg BW， representing 0.10%-247.46% of the safe intake. The main food source of OTA was rice with a contribution rate of 87.22%-98.32% among different scenarios.Conclusions The OTA intakes through grains and related products consumption by Zhejiang population do not raise safety concerns except a few high intake groups， especially young consumers.

Abstract:Objective To understand the microbial contamination status of retail Chinese salads in Huzhou， and conduct a fast quantitative risk assessment to provide reference for foodborne disease prevention and control.Methods In 2019 and 2020， 461 samples of retail Chinese salads were randomly collected and detected for E.coli， Salmonella， Listeria monocytogenes， and B.cereus. According to the relevant standards， the status of microbial contamination was evaluated， and the health risk was preliminarily evaluated by sQMRA tool.Results The unqualified rate of E.coli in retail Chinese salads was the highest （48.94%， 46/94）， and the average concentration was 104.34 CFU/g， which was mainly in the circulation links of farmer’s markets and online stores （P = 0.004）. The detection rates of Listeria monocytogenes， S.aureus， Salmonella and B.cereus were 9.54% （44/461）， 5.21% （24/461）， 1.30% （6/461） and 1.06% （1/94）， respectively. The unqualified rates of S.aureus（≥10⁴ CFU/g） and B.cereus （≥10⁵ CFU/g） were zero. The estimated annual incidence of four food borne pathogens was 2 208 cases， the estimated probability was 7.21 × 10^-4， and the risk level was medium.Conclusion The sanitary quality of retail Chinese salads in Huzhou City is not optimistic， E.coli contamination is the most serious. The contamination of four major food borne pathogens can lead to certain health risks. And further surveillance， assessment and management are needed．

Abstract:Objective To analyze the levels of dioxin contamination in pork and pork liver from five provinces of China： A， B， C， D， and E， and evaluate the dietary exposure of the population， aiming to provide fundamental data for the future formulation of national limit standards of PCDD/Fs.Methods A total of 146 pork and pork liver samples were collected during 2013 to 2019. According to the national standard method "Determination of Toxicity Equivalent of Dioxins and Analogues in Foods" （GB 5009.205-2013）， 17 polychlorinated dibenzo-p-dioxin/furans （PCDD/Fs） in food samples were detected by isotope dilution chromatography/high resolution dual-focusing magnetic mass spectrometry （HRGC/HRMS）. Based on the food consumption data， the dietary exposure via pork for the population was assessed.Results The median TEQ concentration of dioxin in pork and pork liver samples was 0.106 pg/g·fat and 2.32 pg/g·fat， respectively. The concentration of PCDD/Fs in pork in various regions were sequentially decreased by A （0.859 pg/g·fat）>D（0.145 pg/g·fat）>C（0.097 4 pg/g·fat）>B（0.039 9 pg/g·fat）>E（0.023 pg/g·fat）， and the decreased order of PCDD/F levels in pork liver samples from various regions was A （3.616 pg/g·fat）>B （1.84 pg/g·fat）>D（1.313 pg/g·fat）>E（0.85 pg/g·fat）. The patterns for 17 congeners of PCDD/Fs in pork and pork liver samples were similar and OCDD was the dominant congener， accounting for 95% and 90% of the total mass concentrations， respectively. As for the TEQ concentrations， the congener patterns of PCDD/Fs in pork and pork liver samples were inconsistent. In addition， it also varied greatly in the congener patterns of PCDD/Fs for the same class of food samples from different regions. The median intakes of PCDD/Fs via pork for local residents in the five regions ranged from 0.192 to 2.054 pg/kg·bw/month， which were all lower than the PTMI value recommended by JECFA （70 pg/kg·bw/m）.Conclusion PCDD/Fs contamination in pork and pork liver existed in some areas of China. Spatial difference in PCDD/F levels was observed among the five areas and higher levels of PCDD/Fs for pork existed in developed areas . Residents showed low risk of dioxin exposure via pork intake overall. It is necessary to take long-term monitoring on the levels of PCDD/Fs in retailed food covered the larger area in China， and comprehensive exposure assessments of dioxins from various food categories should be further carried out to ensure the food safety of livestock and human health in the future.

Abstract:Objective To evaluate the dietary quality of flight crew by military diet balance index （DBI） and provide basis for their dietary guidance and nutritional intervention.Methods Dietary survey was carried out by weighting method in three air force troops. The dietary quality of flight crew was evaluated by military DBI.Results Compared with GJB 826B-2010 （Dietary Ration for Soldier）， the intake of cereal and soybean met the standard， the intake of red meat， egg， plant oil and fruit was above the standard， the intake of other kinds of food was below the standard. The intake of vegetable， edible fungus， poultry meat， fish and shrimp， milk was insufficient， reaching 84.00%， 61.68%， 54.59%， 45.15% and 36.99% of the standard respectively. Compared with the recommended intake of the general population in the dietary guidelines for Chinese residents （2016）， the intake of salt was over the standard， the intake of added sugar was below the standard. Compared with GJB 823B-2016 （Dietary allowances for military personnel）， the intake of zinc， vitamin A， vitamin B₁ and vitamin B₂ was below the standard， reaching 89.85% 87.53%， 69.33% and 64.33% of the standard respectively. The intake of sodium， iron and vitamin E was above the standard， reaching 232.82%， 241.07% and 353.77% of the standard respectively. The energy supply ratio of protein， fat and carbohydrate was 17.44%， 43.87% and 38.71% respectively， which was obviously unbalanced， showing a “high fat and low carbohydrate” pattern. The food quantitative results were basically consistent with the military DBI scores， showing a slight imbalance.Conclusion The dietary pattern of the investigated flight crew was unreasonable； some of the food and nutrients intake were insufficient； the military DBI score showed that the dietary pattern was slightly unbalanced. The dietary pattern should be further adjusted， and the nutritional health education should be strengthened to promote reasonable nutritional behavior.

Abstract:Objective To analyze the risk factors and links of pork consumption behavior in the family scene， the current situation of pork purchase， transportation， storage， cooking and other related consumption behaviors of residents' families were investigated.Methods A random sampling survey was conducted to investigate the main buyers and cookers of pork in households from September to November 2020 in Sichuan， Hunan and Guangxi， the major pork production and consumption provinces. Through face-to-face inquiry， the demographic characteristics， pork purchase， transportation， storage， cooking and cutting board tool cleaning methods of 480 respondents were obtained. The current situation of pork consumption behavior and food safety risks of residents' families were analyzed.Results Most of the respondents were women （84.2%， 404/480）， aged 45 and above （78.1%， 375/480）. In the processing of purchase and transportation， 56.0% （269/480） of the respondents only bought pork in the vegetable market， and rural residents were more willing to buy pork in the vegetable market than urban residents （P<0.05）. After purchasing， 96.9% （465/480） of the respondents put the pork in food bags seperately and get home within 1 h without ice bags during transportation. During the storage process， 28.4% （135/475） of the pork eaten that day was stored at room temperature， of which 41.5% （54/130） of them was stored for more than 2 hours. In the cooking process， only 18.5% （43/233） of the respondents covered the container with preservative film when marinating pork at room temperature， 71.9% （345/480） of the respondents judged whether the pork was fully cooked according to the color and hardness of the pork， and no respondents used thermometer. After the pork was cooked， 85.0% （408/480） of the respondents did not eat it all at one meal， and the leftover was open stored even overnight. For the evaluation of good practice， the proportion of sepertate chopping boards and knives among urban residents was higher than that of rural residents significantly （P<0.05）. At the same time， 45.2% （211/467） of the respondents did not wash their hands under running water for 20 s before cooking pork.Conclusion In the three southern provinces， both urban and rural residents have potential food safety risks in household consumption such as pork purchase， transportation， storage and cooking. Targeted publicity， education and intervention on food safety of family chefs and family members should be strengthened.

Abstract:Objective Biomedical innovation has become the main battlefield of global science and technology competition， this paper is to explore the evaluation index system for biomedical innovation ability system， and to provide theoretical tools and new perspectives for the evaluation of biomedical innovation ability in China.Methods This article determines the key factors that affect biomedical innovation by literature investigation， Delphi expert consultation， normalization method based on expert score， principal component analysis and other methods.Results the evaluation index system of biomedical innovation ability in China was determined， including 6 primary indexes and 22 secondary indexes. The weight coefficients of each index level and the combined weight coefficients of specific evaluation indexes are obtained. At the same time， the current level results of China's biomedical innovation ability evaluation system are obtained.Conclusion This article establishes an index system for biomedical innovation capability， the current status of biomedical innovation system in China is evaluated， and it is found that the policy environment， the number of researchers and the investment of R&D institutions play an important role in the development of biomedical innovation capacity in China， and provides support for enhancing China's biomedical innovation capability.

Abstract:Objective The purpose of this study is to compare genotoxicity methods between OECD test guidelines and China food safety standards（GB15193）．Methods Main parameters of related genotoxicity methods in OECD Testing Guidelines and GB 15193 standards were compared and analyzed．Results The methodology system of genotoxicity tests was similar between OECD and GB15193. However， there were some different recommendations in some parameters including cells/animal selection， treatment concentrations/dose selection and evaluation of results， etc.Conclusion As a set of internationally recognized standards， OECD test guidelines can be beneficial to the improvement of GB15193 standards on genotoxicity.

Abstract:Objective An incident of foodborne diseases was investigated and analyzed to provide reference for the prevention of such incidents.Methods Suspicious food， pathogenic factors and pollution sources were found through on-site epidemiological investigation， food hygiene investigation and laboratory testing.Results A total of 198 cases were searched， and the incidence rate was 50.13% （198/395）. The main symptoms were diarrhea （90.40%）， fever （87.88%） and abdominal pain （66.16%）， the average incubation period was 13.8 h （4-47 h）. Salmonella enteritidis was detected in 57 cases， 3 foods， 2 raw materials and 1 object surface. Pulsed field gel electrophoresis molecular traceability analysis was carried out on 3 foods， 2 food raw materials， 1 object surface and 11 randomly selected case samples. The result showed that the similarity of DNA fingerprints of the above samples was 100%.Conclusion The incident was a foodborne disease caused by eating hot dog salad bread contaminated by Salmonella. It is suggested that the food regulatory authorities should strengthen the supervision of food production enterprises and the training of food safety related knowledge for food practitioners to avoid similar incidents.

Abstract:Objective To analyze the epidemiological characteristics of mushroom poisoning events in Changsha to provide reference to map out intervention strategies.Methods The epidemiological characteristics of mushroom poisoning events in Changsha reported through “Foodborne Disease Event Reporting System” from 2016 to 2020 was described.Results A total of 203 mushroom poisoning events were included with 618 poisoning cases and 15 deaths in Changsha from 2016 to 2020. The mushroom poisoning events mainly occurred during June to Sepetember， in rural areas and home sittings. The high-incidence areas were Ningxiang City， Changsha County and Liuyang City. From 2016 to 2020， the number of mushroom poisoning events that occurred in the central city area of Changsha （Furong District， Kaifu District， Yuelu District， Tianxin District and Yvhua District） was lower than that occurred in the surrounding counties and cities of Changsha （Wangcheng District， Changsha County， Ningxiang City and Liuyang City）（χ²=17.117， P=0.002）. In 2017， the number of mushroom poisoning events in Changsha was the biggest， and the number in other years was similar， and the number of deaths showed a decreasing trend.Conclusion The mushroom poisoning events in Changsha has seasonal and regional high-incidence characteristics. The measures of publicity intervention for residents over 50 years old in rural areas of surrounding counties and cities should be improved to reduce the occurrence of mushroom poisoning events.

Abstract:Objective To study the epidemiologic and etiologic characteristics of foodborne diarrhea in Jiangxi Province between 2018 and 2019， so as to provide a scientific reference for its prevention and control.Methods Pathogen isolation and identification of foodborne diarrhea samples from the 36 hospitals in Jiangxi Province were carried out. The data collected by National Foodborne Disease Surveillance and Report System were used to analyze the epidemiological characteristics through geographic information system technology and descriptive epidemiological method.Results A total of 5 817 cases of foodborne diarrhea were collected and 504 strains of pathogenic microorganisms were detected， with the overall detection rate at 8.67%（504/5 817）. The detection rates of Salmonella， Vibrio parahaemolyticus， diarrhogenic Escherichia coli， Shigella， Campylobacter jejuni and norovirus were 3.11% （181/5 817）， 0.46% （27/5 817）， 3.87% （225/5 817）， 0.28% （16/5 817）， 0.38% （22/5 817）， 0.58% （33/5 817）. The pathogen detection rate was the highest in the third quarter. There was statistically significant difference in the detection rates of the pathogenic microorganisms in different quarters （P<0.05）. The male-female ratio was 1.2：1， 0-19 years old group accounted for 52.14% of the total cases. There was statistically significant difference between the detection rates of 0-19 years old group （10.55%， 320 / 3 033） and that of age 20 years and older group（6.61%， 184 / 2 784）（P<0.05）. There was statistically significant difference in the detection rates between the group aged 65 and older （9.88%， 56/567） and the group aged 20-64 （5.77%， 128 / 2 217）（P<0.05）. The dining places of positive cases were mainly at home. Suspicious food was mainly mixed food followed by meat and meat products and aquatic animals and their products. Nanchang （9.56%） （92/962）， Xinyu （9.33%） （46 / 493）， Jingdezhen （9.26%） （55 / 594） had higher detection rates of pathogenic microorganisms of foodborne diarrhea， while Ganzhou （7.22%） （40 / 554） and Jian （7.02%） （29/413） had lower detection rates.Conclusion Diarrhogenic Escherichia coli and Salmonella typhimurium were the main pathogens which caused food-borne diarrhea in Jiangxi Province. The majority of patients were juveniles. The detection rates of pathogenic microorganisms showed a geographic characteristics of high in the northern and central Jiangxi， and low in the southern Jiangxi.

Abstract:Objective To analyze a suspected poisoning event of edible wild vegetables by laboratory analysis， and provide scientific basis for the treatment of poisoning event and the treatment of patients.Methods The samples were qualitatively and quantitatively determined for atropine， scopolamine and anisodamine by liquid chromatography-triple quadrupole tandem mass spectrometry （LC-MS/MS）. Morphological identification was carried out on the suspicious plants collected on site， and the poisoning factors were determined by epidemiological investigation.Results On the day of poisoning， tropane alkaloids， such as atropine， scopolamine and anisodamine， were detected in the wild vegetable cake and biological samples provided by the hospital. The poisonous plant was identified as Datura stramonium L using morphological analysis. The clinical symptoms and incubation period of the patient were similar to the poisoning performance of Datura stramonium L.Conclusion The food poisoning was caused by Datura stramonium L， the laboratory test results played a key role in the rapid and accurate identification of the poisoning event.

Abstract:Food contamination of pathogenic bacteria poses a serious threat to human health. Accurate and rapid detections of pathogenic bacteria in food stuff are of great concerns， which are necessary to reduce outbreaks of foodborne diseases. Although traditional culture-based detection of pathogen are reliable and classical， they suffer from cumbersome and time-consuming. Recently， various detection strategies based on electrochemistry and optical spectroscopy using advanced nanomaterials and micro-analytical systems have emerged as portable and ultrasensitive sensing platform. This review focuses on several typical rapid detection method for foodborne pathogens， and emphasizes the negative effect of interference to these detection systems. Some sample processing method for achieving accurate detection are listed. Finally， taking typical food-borne pathogens as examples， the development status and future research directions of rapid detection technology are briefly described.

Abstract:Tea is popular at home and abroad for its unique flavor and bioactive substances that are beneficial to human health. However， as a special economic crop with a long production chain， the background of microorganisms involved in the production process of tea is still unclear， and potentially harmful microorganisms and mycotoxins are present in tea. Nowadays， the investigation shows that the risk of mycotoxin exposure caused by tea drinking is very low， but the monitoring of fungi and mycotoxin contamination in tea and the source of related harmful secondary metabolites need to be solved urgently. In this paper， the research on the contamination situation， prevention and control of fungi and mycotoxin in tea is reviewed. The potential contamination risk of mycotoxin in tea is analyzed and discussed in order to provide reference for the assessment and control of mycotoxin contamination in tea and promote the establishment of good tea quality management and hygiene control systems.