Abstract:Objective To investigate the antimicrobial resistance characteristics of Salmonella spp. isolated from retail whole chickens in Beijing， analyze the prevalence and genomic characteristics of cefotaxime （CTX）-resistant strains.Methods Salmonella strains were isolated from retail whole chickens in urban Beijing， and were subjected to antimicrobial susceptibility testing. CTX-resistant strains were selected for serum-hemagglutination analysis and whole-genome sequencing， and bioinformatics methods were used to analyze the genomic characteristics of the strains.Results The contamination rate was 67.8% （67/87）. A total of 180 Salmonella strains were isolated from 87 samples， of which 98.9% （178/180） of the strains showed resistance to at least one antibiotic， with nalidixic acid （86.1%， 155/180） being the most resistant one， and 69.4% （125/180） of the strains were multi-drug resistant （MDR）. Genomic analysis of 37 CTX-resistant strains identified 6 distinct serotypes and 6 sequence types （ST）， with Kentucky/ST198 （16/37， 43.2%） and Indiana/ST17 （13/37， 35.1%） being the predominant serotype/ST combinations. Core genome multilocus sequence typing （cgMLST） revealed high genetic diversity， which correlated well with serotypes and ST types. The predominant ESBL-encoding gene was bla_CTX-M-55（51.4%， 19/37）. Quinolones resistance was primarily mediated by aac（6'）-Ⅰb-cr （29.7%， 11/37） and chromosomal point mutations， among them 75.7% of the strains notably harbored four mutations simultaneously at sites in GyrA （S83F， D87N/D87G） and ParC （T57S， S80I/S80R）. Additionally， three imipenem- resistant Salmonella Indiana strains harbored the bla_NDM-5 gene.Conclusion Salmonella contamination in retail whole chickens in urban Beijing is highly widespread， accompanied by a high prevalence of antimicrobial resistance. Most CTX-resistant strains harbored multiple resistant mechanisms. Notably， the detection of carbapenem resistance in MDR Salmonella Indiana poses new risks and challenges for public health and clinical infection treatment.

Abstract:Objective To develop an accurate and efficient binary classification model for predicting the binding capacity of endocrine-disrupting chemicals （EDCs） to the G protein-coupled estrogen receptor （GPER）.Methods GPER binding data for 224 compounds were collected. Based on molecular descriptors and Molecular ACCess System fingerprints （MACCS）， six machine learning algorithms including random forest （RF）， artificial neural network-back propagation （ANN-BP）， extreme gradient boosting （XGBoost）， support vector machine （SVM）， k-nearest neighbors （k-NN）， and linear discriminant analysis （LDA） were employed to construct binary prediction models.Results RF， SVM， ANN-BP， k-NN and XGBoost models built with MACCS fingerprints achieved accuracies >90% and Areas of under curve （AUC） values >92% in 10-fold cross-validation， while the RF model reached 85% accuracy on the external test set. SHapley Additive exPlanations （SHAP） analysis indicated that molecules containing at least one hydrogen-bearing oxygen atom， an 8-membered or larger ring system， and a tertiary （or higher） carbon center within the ring are favorable for GPER binding.Conclusion Based on structural representation and model performance evaluation， the RF classification model built upon MACCS fingerprints was identified as the optimal model. SHAP analysis revealed that molecules containing at least one hydrogen-bearing oxygen atom， 8-membered rings or larger cyclic structures， and tertiary carbon （or higher connectivity） centers within rings may mimic certain structural features of estrogen， thereby facilitating interaction with estrogen receptors. These findings provide a theoretical foundation for the endocrine disruption mechanisms of EDCs and offer a methodological tool and theoretical basis for the targeted screening of emerging contaminants in food.

Abstract:Objective To explore the stability and allergenicity of Litopenaeus vannamei shell protein， identify the categories of allergenic proteins， and predict the antigen epitopes.Methods After extracting crude protein from shrimp shells using salt precipitation， L. vannamei shell protein was treated sequentially with heat， acid/base， and simulated gastric digestion， followed by electrophoretic analysis. Serological method was used to identify bands that L. vannamei shrimp shell protein bind specifically to antibodies from the serum of allergic patients， and then the bound protein bands were analyzed using liquid chromatography-tandem mass spectrometry. Bioinformatics analysis were employed for allergenicity analysis and B-cell linear epitope prediction， based on mass spectrometry results.Results L. vannamei shell protein was relatively stable to heat， however it was unstable in acidic and alkaline conditions and was easily digested by simulated gastric fluid. The molecular weights of the proteins in L. vannamei shell that specifically bound to antibodies from allergic patients were approximately 75 kDa. The main potential allergenic proteins present in L. vannamei shells were hemocyanin and β-1，3-glucan binding protein.Conclusion The existence of hemocyanin in the shells of L. vannamei， which may be an allergenic protein with high molecular weight and exhibited thermal stability but being easily digested by gastric juic. This study provides evidence for the allergenicity evaluation of L. vannamei shell products and the necessity for their low-allergen processing.

Abstract:Objective To explore the current status of Chinese residents’ cognition-attitude towards three dimensions： traditional Chinese medicine （TCM） health preservation theory， health claims of diet therapy， food and medicine homology substances， and to provide evidence-based policy recommendations， to guide the regulation of health claims for food-medicine homologous substances， aligning with the principles of TCM for relevant departments in China .Methods According to the official economic regions of China， as defined by the National Bureau of Statistics， the sampling frame was constructed. Five provinces and municipalities namely Beijing， Guangdong， Sichuan， Jiangxi and Heilongjiang were selected as survey regions. The basic information of residents was analyzed by frequency. The status quo of residents’ cognition-attitude was analyzed by description， and the differences of residents in different regions were analyzed by Pearson’s chi-squared test.Results A total of 1 183 valid questionnaires were collected. Residents had certain understandings on following the natural cycles of the four seasons， promoting health by regulating the fundamental substances （“qi”， blood， and body fluids）， “Zangfu” Organs， and meridian systems. Most residents （99.2%） believed that dietary care can achieve TCM health preservation， and 78.36% of the residents believed that the effects of TCM for health preservation were good or very good. The highly frequent phrases of health claims that the residents selected were “nourishing the liver”， “strengthening the spleen”， and “nourishing the stomach” in the organ-based health claims， “replenishing qi”， “replenishing blood”， and “strengthening the muscles and bones” in the health claims related to the circulation of “qi”， blood and body fluids through meridians， and “drying up the dampness”， “lowering the fire”， and “cooling the heat” in the health claims for resisting external pathogenic factors. 94.33% of residents supported labeling food with TCM health claims， and 88.16% of residents knew about food and medicine homology substances， 92.52% of the residents considered that edible dose of the food and medicine homology substances should be clearly defined.Conclusion The building of the health claim corpus for food and medicine homology substances should conform to the characteristics of TCM health preservation in China， focusing on health claims that are highly demanded by the residents. The professional and standardized application of health claims for food and medicine homology substances should be promoted and facilitated in health and market management.

Abstract:Objective To analyze the microbial community structure， distribution of antibiotic resistance genes and virulence factors in Flammulina velutipes using metagenomic sequencing， and explore its potential food safety risks.Methods Nine retail F. velutipes samples were detected. Total DNA was extracted for metagenomic sequencing， and bioinformatics methods were used to analyze the microbial community composition， antibiotic resistance genes and virulence factors.Results Metagenomic sequencing results indicated that the dominant bacterial phyla in F. velutipes were Pseudomonadota and Bacillota， and the dominant bacterial genera were Ewingella， Leuconostoc， and Pseudomonas. Common foodborne pathogens such as Salmonella enterica， Yersinia enterocolitica， and Listeria monocytogenes were annotated in all nine samples， but with low relative abundances. Microbial diversity was higher in the lower segments than in the upper segments of F. velutipes. While environmental bacteria and pathogens were predominant the upper segments， in contrast， lactic acid bacteria predominated in the lower segments. A total of 2 394 virulence factors were annotated， among them most related to virulence mechanisms such as capsules， flagella， and oligosaccharides. A total of 242 antibiotic resistant genes （ARGs） were annotated， among which rosb （23.68%） and baca （23.41%） had the highest relative abundances， and most ARGs corelated with multidrug resistance mechanism. Species taxonomic annotation was carried out for 68 metagenome-assembled genomes （MAGs）. Of all the MAGs， the dominant phyla were Bacillota and Pseudomonadota， and the dominant genera were Leuconostoc， Pseudomonas， and Lactococcus.Conclusion F. velutipes harbor various foodborne pathogens， virulence factors， and resistance genes， posing significant food safety risks. Enhanced microbial monitoring and corresponding control measures should be implemented throughout the food chain.

Abstract:Objective To conduct a preliminary quantitative exposure assessment of Listeria monocytogenes in fresh edible mushrooms from Guizhou province.Methods Microbial and its pathogenic factor monitoring results from the 2021—2022 food safety risk monitoring project were taken for analysis. The Baranyi model， combined with the Belehradek model， was selected， and @RISK software was applied to simulate the growth of L. monocytogenes at all stages from sales to consumption.Results The final contamination level of L. monocytogenes in fresh edible mushrooms from Guizhou province was 1.10 CFU/g. The final contamination level was closely corelated with initial contamination level， transportation temperature and time. The initial contamination level had the strongest correlation with the final contamination level， with a correlation coefficient of 0.96.Conclusion At present， there is a certain level of L. monocytogenes contamination in fresh edible mushrooms in Guizhou province， and there is a certain exposure risk. It is recommended to strengthen the supervision of fresh edible mushrooms sales and related publicity and education. A comprehensive risk assessment should be conducted as a next step to recognize the potential risk of fresh edible mushrooms in causing listeriosis.

Abstract:Objective To analyze the contamination characteristics of lead in commercially available aquatic products in Shenzhen City from 2022 to 2024， and assess the associated health risks of human exposure.Methods A total of 716 commercially available aquatic product samples were collected in Shenzhen City from 2022 to 2024. The lead content was determined using inductively coupled plasma mass spectrometry （ICP-MS）. The contamination characteristics of lead were analyzed， and the pollution level was evaluated using the single-factor pollution index method. The health risks of lead exposure through aquatic product consumption were assessed using the margin of exposure （MOE） method.Results The detection rate of lead in Shenzhen’s commercially available aquatic products is 81.6%， with a concentration range from ND to 5.746 mg/kg. The highest lead levels were found in shellfish， followed by crustaceans and cephalopods， while fish exhibited the lowest lead content. Among the 716 samples， two exceeded the maximum limit set by National Food Safety Standard for Contaminants in Food （GB 2762—2022）， yielding an over-limit rate of 0.28%. Although 3.6% of crustacean samples and 10.1% of shellfish samples showed mild contamination， and 0.6% of shellfish samples exhibited severe contamination， the lead contamination in all four categories of aquatic products was within safe levels. The MOE of lead exposure through aquatic product consumption was greater than 1.Conclusion A certain detection rate of lead was observed in market-sampled aquatic products from Shenzhen City， yet the rate of samples exceeding the national limit standard was at an extremely low level. The MOE assessment indicated a low health risk from lead exposure via aquatic product consumption， but the lead content of shellfish and the resulting dietary exposure in high-consumption populations warrant particular attention.

Abstract:Objective The aim of this study was to analyze the concentrations of eugenol residues in live freshwater fish and shrimp， and to evaluate potential human health risks associated with their consumption in Chongqing City.Methods The eugenol concentrations of 121 fresh freshwater fish and shrimp samples were determined using ultra-performance liquid chromatography-triple quadrupole mass spectrometry （UPLC-MS/MS） with isotope-labeled internal standard. The estimated daily intake （EDI） of eugenol from consuming these products was calculated based on food consumption data. Risk assessments were performed using the acceptable daily intake （ADI） values of 2.5 mg/（kg·BW/d） （JECFA， 2006） and 1.0 mg/（kg·BW/d） （EFSA， 2012）.Results The detection rate of eugenol in fish samples was 68.75% （66/96）， with an average level of 0.403 mg/kg. No eugenol was detected in all 25 shrimp samples. The highest eugenol level （11.9 mg/kg） was found in a grass carp sampled from an agricultural product market. For fish species， the detection rates of eugenol in grass carp， hypophthalmichthys molitrix， and crucian carp were 78.12%， 78.26%， and 58.33% respectively， with average concentrations of 0.637， 0.363， and 0.197 mg/kg. Fish samples from agricultural product markets had significantly higher eugenol concentration （0.557 mg/kg） and detection rate （76.00 %） than those from retail stores （0.236 mg/kg， 60.87%） （P<0.05）. The EDI of eugenol through fish diet for individuals aged above 3 years old is between 0.16×10^-3~8.82×10^-3 mg/（kg·BW/d）， accounting for less than 1% of the ADI.Conclusion Eugenol residues were detected in live freshwater fish samples other than shrimp samples in Chongqing City. Based on current monitoring data， the health risks associated with eugenol in live freshwater fish are relatively low.

Abstract:Objective To study the similarities and differences between Chinese and Russian prepackaged food labelling standards， in order to promote high-quality development in bilateral trade of prepackaged food imports and exports， and providing reference for further amendment of China’s imported prepackaged food labelling standards.Methods Current prepackaged food labelling standards from both China and Russia were collected and analyzed. The similarities and differences of annotation requirements and the compatibility of annotation standards between the two countries were compared. A comprehensive comparative analysis was performed to evaluate the differences between the standards.Results The prepackaged food labelling standards of China and Russia differed in terms of the establishment of labelling indicators and limit requirements， with each country having its own logic in building its standard system. Overall， while there were considerable similarities in terms of product authenticity， date， and production information labelling between the two countries， there were significant differences in areas such as ingredient labelling， the use and labelling of food additives， and nutrient content labelling， which are prone to causing food safety issues. Both countries have their own standard systems， but the overall differences are not significant.Conclusion Differences in China-Russia prepackaged food labelling standards are one of the factors influencing the risks associated with cross-border trade in prepackaged food products. Therefore， import-export enterprises and regulatory authorities should prioritize addressing labelling discrepancies， strengthen risk awareness， strictly prevent food safety issues， and further improve domestic prepackaged food labelling standard system.

Abstract:Objective To investigate and analyze the epidemiological characteristics of an outbreak of foodborne disease in school K， explore key procedures and response measures for on-site management of such outbreaks， and to provide a basis for the future management and prevention of similar incidents.Methods Descriptive epidemiological methods were used to analyze the epidemiological characteristics of the event. A case-control study was employed to investigate and validate suspected meals， dining locations， and foods. Environmental hygiene surveys were conducted to identify potential contamination processes. Laboratory tests were performed on biological specimens from affected students， food handlers in the school cafeteria， food samples，and food processing environment samples to confirm the pathogen.Results The outbreak exposed 3，985 individuals， with 83 cases reported （attack rate： 2.08%）. Among 89 tested samples， 19 （21.35%） were positive for S.aureus producing enterotoxin type A . Core genome multilocus sequence typing （cgMLST） clustering analysis revealed that 17 S.aureus， isolated from chicken cutlets， knives and cutting boards used for processing chicken，food handlers， and affected students， shared homology. This confirmed contamination of the chicken cutlets with S.aureus producing enterotoxin type A from handlers or the environment.Conclusion This outbreak was caused by consumption of chicken cutlets contaminated by S.aureus producing enterotoxin type A from food handlers or the environment in School K. The evidence chain was complete. Timely collection of patient specimens for multiplex PCR testing enabled rapid identification of potential pathogens. and whole-genome sequencing technologies improved the etiological confirmation rate in foodborne disease outbreak investigations.

Abstract:Objective To analyze the current research status of synthetic biology in the field of food safety， identify research hotspots and development trends， and provide reference for the formulation of food safety management standards and risk assessment strategies in China.Methods Based on the Web of Science core collection database， literature search was conducted， and VOS viewer software was used to perform co-occurrence analysis of keywords， achieving visual measurement of research topics.Results The number of synthetic biology research in the field of food safety is showing a stable growth trend. High frequency keyword analysis reveals that current research hotspots focus on food processing technology and risk assessment， the relationship between food safety and climate change， the application of synthetic biology in crop improvement， and the safety of genetically modified microorganisms in food applications.Conclusion Synthetic biology provides innovative solutions for ensuring food nutrition supply and reducing environmental impact， but the associated new risks urgently need to be addressed with caution. It is urgent to establish a scientific regulatory evaluation system and deepen its application while ensuring safety， and to build a more resilient and sustainable food system.

Abstract:With the continuous improvement of living standards， food safety issues have increasingly become a focal point of social concern， among which the problem of plasticizer contamination in food has garnered significant attention. Plasticizers are primarily used as plasticizers and softeners in products such as plastics and rubber. Among global plasticizer products， phthalate esters rank first in production， accounting for approximately 80% of the total output. The widespread application of products containing phthalate ester plasticizers （such as plastic bags， bottles， and cosmetics） in human production and daily life leads to inevitable human exposure through ingestion， inhalation， and dermal contact. As a result， phthalate ester plasticizers have become one of the most prevalent organic pollutants worldwide. This paper systematically elaborates on the physicochemical properties and health hazards of phthalate ester plasticizers， and reviews the limit standards for phthalate esters in food and food contact materials established by major countries and regions worldwide. Based on case analyses of typical plasticizer contamination incidents， the study focuses on proposing management recommendations for controlling phthalate esters in food from multiple dimensions， including raw material and packaging material control， production process management， and finished product quality monitoring. The aim is to provide technical references for food enterprises in constructing a plasticizer prevention and control system.