Abstract:Objective Laboratory confirmation was conducted on 44 stool， food and environmental samples from a suspected case of infant botulism.Methods According to the National Standard GB 4789.12—2016， Clostridium spp. isolation， identification and botulinum neurotoxins （BoNTs） determination were carried out.Results Mice injected with the culture supernatant of infant’s and mother’s hand swabs， infant’s diaper swab， infant’s stool and enema samples exhibited the typical signs of botulism before death. The toxicity of culture was enhanced after the treatment by trypsin. The polyvalent BoNTs antitoxin and the monovalent BoNT type E antitoxin could protect mice from death. Also， Clostridium was isolated from the above samples and further characterized by morphological characteristics， virulence gene PCR and strain identification qPCR. The result showed that Clostridium isolated from these samples were C. butyricum that harbors bont/e gene.Conclusion The patient was diagnosed with type E BoNT poisoning that produced by C. butyricum.

Abstract:Objective The impact of standardized grain storage conditions and processing methods of flour products on the migration and alteration of aluminum content in wheat grains and derived products was investigated in order to establish assessment parameters for accurately evaluating the risk of dietary aluminum exposure.Methods Wheat grains were stored for 12 months in a standardized grain depot in China. The grains underwent two stages of treatment， involving four distinct processing methods （grinding， steaming， boiling and baking）. Changes in aluminum content were measured before and after storage and processing， and variation factors of aluminum in wheat and its products were subsequently calculated.Results After 12 months of storage， the aluminum content in wheat showed no significant difference （P>0.05）. Additionally， the impact of storage temperature and humidity on the aluminum content of wheat was minimal （P>0.05）. The variation factors of aluminum in wheat during storage ranged from 0.19 to 2.71. At the milling stage， the aluminum content in wheat flour was significantly lower than that in wheat grain （P<0.05）. Different processing methods exerted varied effects on the aluminum content of wheat flour. Specifically， the aluminum content of bread and steamed bread was higher than that of noodles （P<0.05）. There was no significant difference in aluminum content between bread and steamed bread （P>0.05）. The variation factors of aluminum in wheat products was the highest in baking that higher than 1， followed by steaming and boiling， with a total range of 0.20-1.89.Conclusion No significant effect was observed on the aluminum content of wheat under varying storage durations in a standardized grain depot. However， the influence of different processing methods on the aluminum content of wheat flour was notable. In risk assessment， selecting an appropriate variation factors according to specific circumstances is crucial to enhance the accuracy of the assessment.

Abstract:Objective To establish a method for determination of bufotenine in sauces by ultra-high performance liquid chromatography-linear ion trap mass spectrometry （UHPLC-QTRAP-MS/MS） with pass-through solid phase extraction.Methods Samples were homogenized， extracted with water and ammoniated acetonitrile via ultrasonication. After salting out， the supernatant was taken to adjust the organic phase ratio and pH， then purified by PRiME HLB solid phase extraction column. After dilution and centrifugation with pure water， the purified liquid was detected by UHPLC-QRAP-MS/MS. UHPLC-QTRAP-MS/MS technique automatically triggered an enhanced product ion scan （MRM-IDA-EPI） mode， collecting secondary mass spectra of suspected target compounds for comparison with standard spectra， thereby further identifying positive samples.Results Under optimized conditions， bufotenine can be effectively separated and showing good linearity in the concentration range from 0.2 to 50.0 ng/mL with correlation coefficients exceeding 0.999. The method’s detection limit was 0.4 μg/kg， with an average recovery rate between 99.5% to 106.5% for spiked levels of 5.0， 50.0 and 200 μg/kg. A relative standard deviation from 1.9% to 4.3%.Conclusion It was a simple and rapid method， with secondary mass spectrometry collected by a linear ion trap， meeting the requirements for detecting bufotenine content in sauces.

Abstract:Objective To optimize the sample pretreatment process by using HLB-P/HMR-Lipid SPE purification column. In combination with ultra-high performance liquid chromatoplc-tandem mass spectrometry， a method for simultaneous detection of 19 fluorinated alkyl compounds in liquid milk was established.Methods The sample was extracted by means of acetonitrile dissolving precipitated protein vortex， and the commercial double-layer solid phase extraction column HLB-P/HMR-Lipid SPE was used to purify the lipid. Then the methanol-water （8∶2， v/v） was redissolved after nitrogen blowing， and the mobile phase gradient elution was performed by using methanol and 2mmol/L ammonium formate solution. The targets were separated by ACQUITY Premier BEH C18 column （100 mm×2.1 mm，1.7 μm）， detected by electrospray ion source and negative ion multi-reaction monitoring mode， and quantified by internal standard method.Results The linear relationships of 19 fluorinated alkyl compounds were good in the range of 0.1-50 μg/L， and the correlation coefficient r was greater than 0.995. The limit of detection was 0.003 7-0.009 5 μg/kg and the limit of quantification was 0.012 4-0.031 7 μg/kg. The recoveries of low concentrations（0.1 μg/kg）， medium concentrations（1 μg/kg） and high concentrations（8 μg/kg）in liquid milk ranged from 73.8% to 113.1%， the relative standard deviations were less than 10% （n=6）.Conclusion The method is accurate， reliable， sensitive， reproducible and suitable for the detection of fluorinated alkyl compounds in liquid milk.

Abstract:Objective To establish an analytical method for determination of 11 fluorescent whitening agents in fresh tea drinks using ultra-high performance liquid chromatography-tandem mass spectrometry.Methods The samples were extracted by sonication of N， N-dimethylformamide/water/triethylamine （70∶29∶1， V/V/V） ， added with appropriate precipitant， centrifuged and filtered， finally injected into the UPLC-MS/MS system. The samples were separated on a Waters BEH C₁₈ column （2.1 mm×50 mm，1.7 μm） with acetonitrile and 0.2% ammonia as mobile phase，and detected using electrospray ionization in multiple reaction monitoring mode via positive and negative ions scanning. Compounds were quantified by external standard method.Results The 11 fluorescent whitening agents had good linearity within the measured concentration range， and the correlation coefficients （r） were all above 0.995. The limits of detection were 0.003-0.03 mg/kg. The limits of quantitation were 0.01-0.1 mg/kg. The recoveries were 71.7%-116.% and the relative standard deviations were 0.7%-9.9% in three kinds of fresh tea drinks including milk tea， fruit tea and coffee.Conclusion The proposed method is simple， highly efficient， accurate， and suitable for the detection of 11 kinds of fluorescent whitening agents in fresh tea drinks such as milk tea， fruit tea and coffee， which provides a methods for food safety supervision related to fresh tea production.

Abstract:Objective To develop a method for the determination of 12 organophosphate esters （OPEs） fire retardants in honey by ultra-high-performance liquid chromatography-high-resolution mass spectrometry.Methods The samples were enriched， extracted and cleaned-up by a sugar-induced acetonitrile-water liquid-liquid extraction system， eluted with a gradient of methanol-formic acid-water， and then separated on a HSS T3 chromatographic column （2.1 mm×100 mm， 1.8 μm）. The analytes were determined by high-resolution mass spectrometry in the targeted single-ion monitoring mode， with the quantification by isotope internal standard method.Results The linearity of the 12 OPEs， with R2>0.99， was observed from 0.2 to 20 μg/L， while the range of the LODs and the LOQs were 0.05-0.3 μg/kg and 0.1-0.9 μg/kg， respectively. Recoveries of the 12 OPEs at three different spiked levels ranged from 86.2% to 119.5%， with RSDs ranging from 1.24% to 8.16%. Analysis of 16 honey samples revealed 100% detection of TPhP at concentrations ranging from 1.7 to 11.8 μg/kg and 50% detection of TEP at levels from LOD to 1.5 μg/kg.Conclusion The method is convenient， reproducible， sensitive and suitable for the trace determination of OPEs in honey.

Abstract:Objective A QuEChERS ultra-high-performance liquid chromatography tandem mass spectrometry analytical method for the determination of 10 kinds of organophosphate esters pesticides and 5 kinds of carbamate pesticides in tea drinks was established.Methods The extraction solution was purified with 150 mg MgSO₄， 25 mg Primary-secondary comine and 2.5 mg graphitized carbon black. After centrifugation at 14 000 r/min at 4℃ for 10 min and the supernatant was transferred， diluted with an equal volume of ultra-pure water. The pesticides were separated on a Waters ACQUITY BEH C18 （2.1 mm×100 mm， 1.7 μm） chromatographic column with gradient elution using 0.1% formate-acetonitrile and 0.1% formic acid aqueous solution. Pesticides were detected via multiple reaction monitoring mode.Results The method showed a good linear range of 5-160 μg/L （R²>0.99）. The limits of detection and limits of quantification were 0.05-5 μg/L and 0.15-15 μg/L， respectively. Mean recoveries of 15 kinds of pesticides were 71.2%-103.2%. Intraday （n=6） and interday （n=3） relative standard deviations were 0.1%-13.8% and 0.4%-12.2%， respectively. Matrix effects were 84.1%-114.3%， and could be considered to have no matrix effect. Acephate was detected in 2 out of 43 commercial tea drinks， it suggests that pesticide residues in tea drinks may cause increased health risks for people.Conclusion The method was simple to operate， rapid， accurate， and suitable to detect fifteen kinds of pesticides in different tea drinks.

Abstract:Objective To investigate the contamination of Norovirus （NoV）， Sapovirus （SaV）， hepatitis A virus （HAV） and hepatitis E virus （HEV） in marine shellfish and water bodies in Shandong Province， Weihai City.Methods From December 2020 to November 2021， a total of 360 samples including fresh shellfish， seawater and sewage were collected from local aquaculture farm， retail markets and sewage treatment plant. After virus particle concentration， nucleic acids were extracted and detected by real-time fluorescent reverse transcription polymerase chain reaction （RT-qPCR） for determination of NoV， SaV， HAV and HEV.Results The total positive rate of four viruses was 31.67% （114/360）. The level of four viruses contamination varied depending on samples types， and the rank of positive rate for different sample types was sewage， sea water， farmed shellfish and retail shellfish in descending order. NoV was the dominant contaminating virus with the total detected rate of 27.78% （100/360）， followed by SaV 8.33% （30/360）， HAV 3.61% （13/360） and HEV 1.39% （5/360）. The detection rate of the four foodborne viruses in samples varied with seasons， and it was the highest detection rate for farmed shellfish， retail shellfish and sewage in summer， with 53.33%， 30% and 100% respectively， and the lowest in autumn and winter. While for sea water， the highest detection rate for the four foodborne viruses was in winter （60%） and the lowest was in summer （6.67%）. In addition， 26.32% （30/114） of the positive samples were mixed contamination with two （26 samples） or three （4 samples） viruses. The occurrence frequency of the two virus mixed combination was NoV-SaV， NoV-HAV， NoV-HEV， SaV-HAVand SaV-HEV in descending order， and the combination of three viruses was NOV-SAV-HAV. The rank of detection rate of viruses mixed contamination in different sample types was sewage， seawater， farmed shellfish and retail shellfish in descending order.Conclusion There was a risk of foodborne viruses contamination in marine shellfish and water bodies in Weihai， and the contamination was seasonal. The issue of viruses mixed contamination needs to be concerned. Additionally， monitoring of foodborne viruses in marine shellfish should be strengthened in Weihai in summer.

Abstract:Objective To investigate the pollution states of lead， cadmium， methyl mercury， inorganic arsenic and chromium for sold aquatic products in Zhuhai City， and to assess their exposure risk.Methods The total of 666 sold aquatic products samples in Zhuhai City were collected during 2018—2022. The level of lead， cadmium， methyl mercury， inorganic arsenic and chromium in samples were analyzed by inductively coupled plasma-mass spectrometry （ICP-MS） and liquid chromatograph inductively coupled plasma-mass spectrometry （LC-ICP-MS）， evaluated by the method of single-factor pollution index and Nemerow integrated pollution index， based on the dietary intake of residents in Zhuhai to assess its potential health hazard.Results Shellfish had the highest levels of lead， cadmium， inorganic arsenic， chromium and fish had the highest levels of methylmercury. The P_n of the four aquatic products was at safe levels， but the P_cadmium of shellfish and cephalopods was mildly contaminated. The average dietary exposures and high-end dietary exposures of lead， cadmium， methylmercury， inorganic arsenic， and chromium to health of resident were acceptable.Conclusion There has been the varying degrees of cadmium pollution of sold aquatic products in Zhuhai City， especially shellfish and cephalopod. It is necessary to strengthen the monitoring of dietary exposure risk of high-consumption groups in cadmium and methyl mercury， and to further carry out cumulative exposure risk assessment.

Abstract:In recent years， as a renewable resource， the development and utilization of plant-based ingredients have become an important emerging force in the development of the food industry. The safety assessment of ingredients involves the utilization of environmental resources and food safety. This paper briefly summarizes and analyzes the common issues in the application materials for the safety assessment of novel food ingredients from plants， introducing the key points that need to be focused on when submitting the application materials， in order to provide reference for scientific and effective evaluation materials for application enterprises.

Abstract:Objective To evaluate the efficacy of plant polyphenols on sarcopenia in the elderly.Methods Relevant studies on the prevention and improvement of sarcopenia by plant polyphenols were searched in PubMed， Web of Science， Scopus， China National Knowledge Infrastructure （CNKI） and Wanfang databases. Meta-analysis was performed on the included randomized controlled trials using Review Manager 5.4 statistical software.Results A total of 9 randomized controlled studies were included after screening. The results of the Meta-analysis demonstrated that plant polyphenols could significantly reduce the body weight， fat mass and lean body mass of the elderly.Conclusion Plant polyphenols cannot prevent sarcopenia by improving the muscle mass of the elderly.

Abstract:Objective To understand the antimicrobial resistance and the mobile colistin resistance gene mcr carrying status of Salmonella isolates recovered from foods in China’s Mainland in 2022.Methods Broth microdilution method was used for testing the antimicrobial susceptibility of 575 Salmonella isolates against 17 antimicrobial compounds which belong to 11 categories， and mcr genes were detected by PCR for all tested isolates， followed by whole genome sequencing and bioinformatics analysis in terms of the mcr gene PCR positive isolates.Results The resistant strains accounted for 84.70% （487/575） of the 575 Salmonella isolates and the resistance rate of the tested strains to nalidixic acid was the highest （58.61%， 337/575）. We found one Salmonella strain resistant to imipenem and another one to tigecycline. The rate of multi-drug resistance of all isolates was 61.39% （353/575）. Some isolates could be concurrent resistant to as much as 10 classes of antimicrobials. There were 147 kinds of antimicrobial resistance spectrums. The dominant resistance spectrum was SAM-CT-AMP-NAL， accounting for 28.57% （42/147）. The antimicrobial resistance rates of Salmonella from different sample sources were significant statistically， with the highest resistance rate （95.51%， 85/89） of Salmonella isolates from frozen raw chickens. Salmonella isolates recovered from both Hebei and Heilongjiang Province got a 100% resistance rate. Six Salmonella strains recovered from Hubei， Hebei， Anhui， Liaoning and Shandong and harboring mcr-1 gene were detected with a detection rate of 1.04% （6/575）， all of them were multi-drug resistant strains. The predominant resistance genes among these mcr-harboring Salmonella isolates were aac （6'）-laa， mcr-1.1， fosA3 and so on， the main plasmid replicon types were IncI2， IncP1 and IncHI2， respectively.Conclusion The Salmonella isolated from foods in China’s Mainland in 2022 got an overall high level of antimicrobial resistance， with serious phenomenon of multi-drug resistance and complex antimicrobial resistance spectrums. In addition， there were also some isolates with multi-drug resistance while carrying mcr gene， which should be given sufficient attention.

Abstract:Resistance of foodborne pathogens to low pH environments is often considered one of important determinant of disease， which helps bacteria pass through the stomach and can cause illness at very low infective doses. The research progress of three major amino acid decarboxylase systems in Escherichia coli， namely glutamic acid decarboxylase system， arginine decarboxylase system and lysine decarboxylase system were summarized. The primary objective is to elucidate the acid-resistant mechanism of foodborne pathogens.