Abstract:Objective To investigate the contamination levels of foods such as woodear， Tremella fuciformis （white jelly fungus）， and rice noodles caused by Burkholderia gladioli pv. cocovenenans， and to elucidate the pathogenic traits of the isolated Burkholderia cocovenenans strains.Methods According to GB 4789.29—2020， a total of 650 samples from seven different food types were collected. Real-time fluorescent quantitative PCR was used to detect the bon gene cluster， while bongkrekic acid levels were measured according to GB 5009.189—2016. Genomic sequencing was performed to elucidate the pathogenic features of Burkholderia cocovenenans.Results Among the 650 samples， 26 strains of Burkholderia cocovenenans were detected， with 22 of these strains isolated from woodear， resulting in a positive detection rate of 15.71%. All strains of Burkholderia cocovenenans harbored the bon and tox gene cluster. The antibiotic resistance analysis revealed that all the strains carry the three antibiotic resistance genes： ceoA， ceoB， and opcM. Phylogenetic analysis indicated that the strains isolated in this experiment belong to the same evolutionary clade as Burkholderia gladioli pv. cocovenenans in the NCBI database， and no significant mutations were observed. Each genome contained between 167 and 184 genes involved in carbohydrate metabolism， with comprehensive metabolic pathways for various polysaccharides， including cellulose， chitin， and starch.Conclusion Woodear are susceptible to contamination by Burkholderia gladioli pv. cocovenenans， which underscores the need for enhanced risk monitoring of this pathogenic bacterium， particularly in woodear.

Abstract:Objective To understand the characteristics and antibiotic resistance profiles of Shiga toxin-producing Escherichia coli （STEC） derived from animals in Shandong Province， providing a basis for the risk assessment and surveillance of STEC infection.Methods A total of 140 STEC strains were isolated from cattle and sheep from 2017 to 2018 in Shandong Province. These strains were tested for the minimal inhibitory concentrations of 27 types of antibiotics in 15 categories using the microbroth dilution method. The detection of extended spectrum beta-lactamases （ESBLs） was conducted by using the double-disk synergy test. The O：H serotyping， Shiga toxin subtyping and antibiotic resistance gene were analysis based on whole genome sequences. The core gene SNP phylogenetic tree was constructed using the maximum likelihood method.Results The 140 STEC strains constituted 45 O：H serotypes， with O157：H7 accounting for 12.86% （18/140）. Two stx1 subtypes and eight stx2 subtypes were detected， and stx1c+stx2b was the most common subtype， followed by the novel stx2k. Sixteen strains （11.43%） were resistant to at least one antibiotic， and 4 strains （2.86%） were multi-drug resistant. The highest resistance rate to tetracycline was observed in the cattle- and sheep-derived STEC strains （8.57%， 12/140）， followed by trimethoprim-sulfamethoxazole （6.43%， 9/140）， with 3 strains were ESBLs-producing strains. All strains were sensitive to meropenem and amikacin. A total of 10 categories of 25 antibiotic resistance genes were detected， including the β-lactamase resistance genes bla_EC， bla_CTX， bla_TEM and bla_OXA， and fosfomycin resistance gene fosA7 was identified for the first time in STEC. 140 STEC strains formed 38 clusters， each containing the same serotype， with the O113：H4 serotype strain being the dominant cluster.Conclusion STEC strains carried by cattle and sheep in Shandong Province are predominantly non-O157 serogroups and exhibit high diversity. The novel fosA7-resistant gene and multidrug-resistant isolates were identified. It is essential to strengthen the management of cattle and sheep feces and enhance monitoring of pathogenic bacteria.

Abstract:Objective To understand the influence of cultivation conditions on the formation of Salmonella biofilm and provide basis for ensure food safety.Methods Congo red staining and crystal violet staining method were used to screen biofilm （BF） formation strains from 400 foodborne Salmonella. Scanning electron microscope was applied to observe BF formation. Whole-genome sequencing analysis was used to identify BF formation related genes. Tube culture and microplate quantitative detection methods were used to determine BF formation of Salmonella under different culture conditions. The effect of different culture time， medium type， glucose content， peptone content and Vitamin B₁ （VB₁） content to Salmonella BF formation were studied.Results Eight （2.00%） BF-forming Salmonella isolates were obtained. Compared to LB medium， BHI was more suitable for BF formation for Salmonella. When cultured for 96 h， the BF formation of Salmonella on BHI was much more than that on LB. Fifteen BF-related genes including trx2， fadI， bsmA， bssS， tabA， bcsE， csgD， csgA， B， C， seqA， dam， fliZ， flhD and motB were detected in BJ44D， ZZSR2-2008， NYSR94-08 and yl19Ta. The best BF formation nutrient conditions for Salmonella were that 0.6% or 0.8% glucose， 4.0% peptone， and 50 mg/L VB₁ were respectively supplemented in BHI broth （P<0.05）.Conclusion It is indicated that different culture conditions significantly correlated with BF formation of Salmonella and have strain-specificity， and can provide theoretical basis for BF formation control of Salmonella in the food production chain.

Abstract:Objective In the experiment，using liquid-liquid extraction solid-phase extraction method to remove fat content and interfering impurities from cocoa products，establishing a high performance liquid chromatography method for detecting the content of dihydroquercetin.Methods After the sample was extracted with methanol-2% acetic acid water （V∶V=1∶1），the fat content in the solution was first removed by liquid-liquid extraction purification，then it was secondary purified by hydrophilic and lipophilic solid-phase extraction column.The mobile phase was 0.1% acetic acid water-methanol，and it was separated by C₁₈ reversed-phase chromatographic column.Finally，it was analyzed by high performance liquid chromatography with diode array detector.Results The dihydroquercetin showed a good linear relationship in the range of 0.1-100 μg/mL，the linear correlation coefficient was 0.999 9，the detection limit was 1 mg/kg，the quantitative limit was 3 mg/kg，the average recovery rate was 101.7%-106.7%，and the RSD was 0.35%-1.60% （n=6）.Conclusion The method can remove fat soluble impurities in cocoa products，with high sensitivity and accuracy，and is suitable for accurate determination of dihydroquercetin content in high-fat foods.

Abstract:Objectives A high-performance liquid chromatography method was developed to determine the purity of theaflavins， a food additive.Methods The samples were dissolved in ethanol-water （2∶8，V/V） solution and separated by C₁₈ reversed-phase chromatography with acetonitrile and 0.1% phosphoric acid as mobile phase. The flow rate was 1 mL/min and the column temperature was 35 °C， the detection was performed at 278 nm using a UV detector.Results The linear relationship of theaflavins was good in the range of 20-500 μg/mL， and the correlation coefficient r²>0.99， the limit of detection of the four components of tea polyphenols was 0.2 μg/mL， and the limit of quantification was 0.5 μg/mL.The recovery rate of the samples was 97.9%-101.3%， and the relative standard deviation was 0.3%-1.6%.Conclusion The method has high precision， good stability， simple operation， and can meet the requirements for the purity determination of food additive theaflavin.

Abstract:Objective To understand the knowledge， attitude and practice （KAP） of residents in the Beijing-Tianjin-Hebei region about Food-medicine substances （FMS）， in order to provide a basis for improving the related policies and regulations as well as guiding residents to consume FMS scientifically.Methods From August to December 2020， a survey on the KAP of residents aged 18 and above in Beijing-Tianjin-Hebei region about FMS was conducted by using online electronic questionnaires with the convenience sampling method， analyzed the proportions of different responses， compared the differences between groups with the chi-square test and Fisher’s exact probability method， and analyzed the frequency of FMS purchased and consumed by the word frequency.Results The 1 119 respondents in the Beijing-Tianjin-Hebei region accurately recognized 23.6% of FMS， and more than 97.0% of them were willing to learn about the knowledge either actively or passively. The top three sources of knowledge about FMS were television and radio， social media platforms and software， doctors and experts. More than 90.0% of the respondents believed that the names of FMS used and the intake limits should be marked on the food labels. More than 75.0% of the respondents scored ≥6 on their understanding of the concepts of FMS， as well as their trust in the knowledge of FMS， recognition of their health-improving effects， and understanding of their functions. 56.1% of the respondents were consumers who regularly purchased food products with FMS， and 95.9% of the respondents purchased FMS for the purpose of improving their physical health. Supermarkets， e-commerce platforms and pharmacies were the main ways for respondents to purchase FMS. When purchasing food products， respondents were mainly concerned about the quality and whether they contained ingredients and functions of FMS. The three types of FMS most frequently purchased and consumed by survey respondents were yam， wolfberry and jujube. There are statistically significant differences in the cognition of FMS among people with different education levels， attitudes towards FMS among people of different genders， ages， education levels， and occupations， and consumption behaviors towards FMS among people of different ages， regions， education levels， and occupations （P<0.05）.Conclusion The knowledge of residents in the Beijing-Tianjin-Hebei region about FMS was insufficient， but they had a positive attitude towards the understanding of FMS， and their willingness to consume and demand for popularization of scientific information was very high. In the future， it is necessary to increase the popularization of FMS related information and demand research， to innovate publicity ways and means， and guide residents to consume FMS in a scientific and reasonable manner.

Abstract:Objective To analyze the contamination levels of 3-MCPDE （3-monochloropropane-1，2-diol esters）， 2-MCPDE （2-monochloropropane-1，3-diol esters） in fried food and puffed food， and we could provide a scientific basis for conducting risk assessment to the exposure levels of MCPDE and GE.Methods We detected chloropropanol esters and glycidyl esters by isotope dilution gas chromatography - tandem mass spectrometry and conducted an analysis of 3-MCPDE， 2-MCPDE and GE contamination levels in 55 fried food samples and 66 puffed food samples.Results The detection rates of 3-MCPDE， 2-MCPDE and GE in fried food and puffed food were all 100%， and the concent range of 3-MCPDE， 2-MCPDE and GE in fried food were 0.052 5-1.59， 0.023 2-0.798 and 0.025 7-3.06 mg/kg. The concent range of 3-MCPDE， 2-MCPDE and GE in puffed food were 0.089 2-2.31， 0.047 7-0.867 and 0.075 5-2.58 mg/kg.Conclusion The results indicated that the contamination levels of 3-MCPDE， 2-MCPDE and GE in puffed food were higher than fried food， and we should put more attention on MCPDE and GE contamination in puffed food.

Abstract:Objective To investigate the microbial contamination of student meals in Yuexiu District of Guangzhou City over seven consecutive years， and to provide a reference for regulatory authorities.Methods Totally 296 student meal samples were collected from 2017 to 2023 in Yuexiu District of Guangzhou City. The microbial contamination of the samples， including the total numbers of colony，Escherichia coli， Staphylococcus aureus，Vibrio parahaemolyticus，Salmonella，Bacillus cereus and Listeria monocytogenes were detected. The results of the monitored samples were evaluated in accordance with Guangdong Provincial Food Safety Local Standard： Microbiological Limits for Non-prepackaged Ready-to-eat Foods （DB 44/006—2016）.Result The total unqualified rate was 26.35% （78/296）， the unqualified rate decreased by 57.50%， 45.24%， 43.86%， 16.67%， 5.00%， 6.38%， and 2.50% from 2017 to 2023 （χ²=68.947， P<0.01）. The results showed that the unqualified rate decreased yearly （χ²=68.947， P<0.01）， indicating that the regulatory measures were effective.In the past 7 years， none of the food-borne pathogenic bacteria in the monitored samples exceeded the standard，and all the unqualified items were sanitary indicator bacteria，among which the total number of colonies exceeded the standard， which further suggested the necessity of improving sanitary conditions.Spearman rank correlation analysis showed a negative correlation between the sample center temperature and the total number of colonies （r=-0.224， P<0.01）， but no significant correlation with Escherichia coli （r=-0.145， P>0.05）.Conclusion The overall trend of microbial contamination in student meals in Yuexiu District， Guangzhou is moving towards improvement. All departments should further strengthen the monitoring and supervision of student meal food to consolidate the previous achievements and prevent the occurrence of campus foodborne diseases.

Abstract:Objective To understand the status of microbial contamination in commercially prepared beverages sold in Huzhou City， and provide reference data for public health supervision and the improvement of standards for commercially prepared beverages in China.Methods From April to October in 2023， a total of 220 samples of freshly prepared beverages were collected in batches from hotels， restaurants， beverage shops， and other food and beverage service establishments in Huzhou City， including four types： those containing fruits and vegetables and dairy products， those containing fruits and vegetables but no dairy products， those containing dairy products but no fruits and vegetables， and those without fruits and vegetables and dairy products. All samples were tested for four hygiene indicator microorganisms ［total bacterial count， mold， yeast， and Escherichia coli （E. coli）］ and three foodborne pathogenic bacteria ［Staphylococcus aureus （S. aureus）， Salmonella， and Listeria monocytogenes］ according to relevant national standards.Results The overall non-conformity rate for the 220 samples of freshly prepared beverages monitored in this study was 19.09%. Specifically， the non-conformity rate for total bacterial count was 5.00%， and that for E. coli was 17.73%. Among the foodborne pathogenic bacteria， S. aureus was detected in 1.82% of the samples， with all counts <10⁴ CFU/mL.There was a statistically significant difference in the non-conformity rate for total bacterial count among different types of freshly prepared beverages （χ2=27.915， P<0.05）. In terms of geographical location， the non-conformity rates for total bacterial count and E. coli in freshly prepared beverages collected from rural areas were much higher than those from urban areas， with statistically significant differences （χ2 _bacteria=11.327， P<0.05； χ2_{Escherichia coli}=19.853， P<0.05）. Mold and yeast were detected in all types of freshly prepared beverages， with the maximum detected value for mold being 4.06 lgCFU/g and that for yeast being 5.37 lgCFU/g.Conclusion The contamination of hygiene indicator microorganisms in freshly prepared beverages in Huzhou City is a matter of concern， primarily due to the high rates of exceeding the limits for E. coli and total bacterial count. Mold and yeast were also detected， with a relatively high average count of yeast.It is recommended that the country establish and improve the limit standards for microorganisms such as mold and yeast in freshly prepared beverages as soon as possible， in order to more effectively address the increasingly complex.

Abstract:Objective To investigate the status of pesticide residues in vegetables sold in Ningbo City and assess the risk of the dietary exposure.Methods From 2020 to 2022， 264 vegetable samples of 7 categories such as leaf vegetables were collected. And about 77 items of 8 major categories of pesticide projects were detected by LC-MS/MS. And the dietary exposure were evaluated by point evaluation method.Results There are 175 vegetable samples were detected containing pesticide residues， and the detection rate is 66.29%（175/264）；According to the National Food Safety Standard for Maximum Residue Limits of Pesticides in Food （GB 2763—2021）， there are 21 vegetable samples have pesticide residues exceeding the standard， and the over-standard rate is 7.95% （21/264）， and there were 51.52% （136/264）vegetable samples with two or more pesticides； There is a statistically significant difference in the detection rates of pesticide residues in 7 types of vegetables （χ²＝32.474，P<0.05）； There is a statistically significantdifference in the detection rates in 8 types of pesticide residues （χ²=276.317，P<0.05）； There is a statistically significant difference in the exceeding rates in 8 types of pesticide residues （χ²=34.274，P<0.05）. The acute dietary intake risk values （%ARfD） of all the detected pesticide are less than 100.00%， but the acute dietary intake risk values （%ARfD） of Cyhalothrin is 95.833， which is the highest among all the detected pesticides； And thedetected pesticide single food safety index values （IFS） were less than 1.00.Conclusion The detection rate of pesticide residues in vegetables in Ningbo City is relatively high， and there is a phenomenon of over-standarding. However， the dietary exposure assessment show that the risks of pesticide residues in vegetables in Ningbo City are within an acceptable range for the general population.

Abstract:With the steady implementation of the Healthy China Strategy and upgraded health-conscious consumption， China’s sports nutrition food industry is undergoing rapid expansion. However， the technical requirements in the current national food safety standards for sports nutrition food still need further refinement， while the scientific regulatory system and evidence base for ingredient efficacy need strengthening. By analyzing global experiences in sports nutrition food development， this study systematically maps China’s standardization progress and regulatory landscape in this field， identifies key challenges， integrates international evidence-based research frameworks， and proposes strategies to establish a scientific evidence-based system through the “Series Review and Commentary on Sports Nutrition”. The series focuses on the ingredients in domestic and international sports nutrition food， employing a three-tiered analytical framework for food safety risk assessment： metabolic characteristics and physiological functions， regulatory approval status across countries and regions， and clinical evidence from systematic reviews， meta-analyses， and randomized controlled trials， thereby providing scientific basis for revising and developing national food safety standards， and references for sports nutrition practices.

Abstract:Objective To analyze the occurrence pattern and epidemiological characteristics of collective food poisoning in Shanghai from 1990 to 2022， and to provide scientific basis for the prevention and control of collective food poisoning.Methods The related information of collective food poisoning in Shanghai from 1990 to 2022 was collected， and its epidemiological characteristics and trends were descriptively analyzed.Results From 1990 to 2022， there were 767 incidents of collective food poisoning in Shanghai， with 25 367 people poisoned. The number of poisoning incidents and the number of poisoned individuals generally showed significant downward trend in general. After 2006， collective food poisoning incidence rate kept at a low level （5 cases per 100 000 individuals）. Collective food poisoning incidents in Shanghai were found mainly in June to September（63.7%，16 164/25 367）， and occurred mainly in collective canteens （46.4%，11 782/25 367）. The main cause of poisoning was cross contamination （43.8%，11 114/25 367）. The main type of poisoned food was dishes （26.4%，6 688/25 367）， and the main pathogen was bacteria（65.0%，16 491/25 367）.Conclusion The collective food poisoning prevention in Shanghai is stable and positive. In the future， efforts should be made to strengthen the monitoring and analysis of foodborne diseases， pay high attention to collective food poisoning incidents that occur during the rainyseason and summer， and focus on preventing bacterial food poisoning caused by cross-contamination.

Abstract:Vibrio parahaemolyticus （V. parahaemolyticus） is a significant foodborne pathogen worldwide， primarily transmitted through the consumption of seafood. It can cause both sporadic cases of acute gastroenteritis and outbreaks of foodborne illness. Severe infections may require antibiotic treatment. In recent years， the bacterium has developed varying degrees of antibiotic resistance， largely due to factors such as waste discharge from antibiotic production， improper practices in aquaculture， and the misuse of antibiotics in clinical settings. This article reviews the current status of antibiotic resistance in V. parahaemolyticus both domestically and internationally. It explores key resistance mechanisms， including biofilm formation， efflux pumps on the cell membrane， modification of drug targets， resistance genes， and plasmid-mediated resistance. Finally， it proposes surveillance and control strategies to address bacterial resistance， laying a solid foundation for future research on antibiotic resistance in V. parahaemolyticus

Abstract:The prepared dish industry offers convenience to the fast-paced social life， and medicinal diet prepared dishes possess the characteristics of dietary nourishment. Against the backdrop of the big health industry， medicinal diet prepared dishes， as an intersecting industry of the medicine and food homology industry and the prepared dish industry， hold significant research implications. However， the development of the medicinal diet prepared dish industry faces numerous challenges， including the applicability issues in nutritional value assessment， the absence of production process standards， the complexity of safety evaluation， and the shortage of compound talent resources. This paper has combed the current state of development and the problems faced by the medicinal diet prepared dish industry， and proposed targeted solutions， aiming to provide references for the healthy and sustainable development of the medicinal diet prepared dish industry.