Abstract:In recent years， quantitative microbial risk assessment （QMRA） for food safety has developed rapidly both domestically and internationally. QMRA integrates multidisciplinary theoretical knowledge and technical methodologies to quantitatively assess the human health risks associated with exposure to pathogenic microorganisms and provides a scientific basis for risk management and risk communication. The classic framework of QMRA includes four steps： hazard identification， hazard characterization， exposure assessment， and risk characterization. Currently， research hotspots include sampling statistics， predictive microbiological modeling， microbial toxicology， computational simulation， and bioinformatics. The key to the development of QMRA lies in how to integrate multi-source data through interdisciplinary approaches to improve the accuracy and reliability of assessment results. In the future， QMRA still faces many technical challenges in terms of data， models， and algorithms. The interdisciplinary integration with other fields such as artificial intelligence， microbial multiomics， bioinformatics， synthetic biology， systems biology， and computational biology will be the focus of research directions， aiming to play a greater role in the fields of food safety and public health.

Abstract:Objective To investigate the effects of different storage temperatures humidity， and processing methods on the contamination levels of four types of Alternaria toxins （AME， AOH， TeA， TEN） in wheat grains， as well as their variations， providing a scientific basis for the safety risk control across the entire wheat and wheat product industry chain.Methods Positive samples were obtained from random sampling in a province for storage experiments and subsequently processed into steamed buns， noodles and bread. The contamination levels of the four types of Alternaria toxins were determined before and after the storage process and processing， and the effects of storage and processing on toxin residues were assessed by the processing factor.Results During the 12-month storage period， the content of the four types of alternaria toxins in wheat showed a trend of first decreasing and then stabilizing. However， the storage duration had no significant effect on contamination levels （P>0.05）. The average processing factors for AME， AOH， TeA， and TEN was 0.77， 0.61， 0.51， and 0.73， respectively. There was no statistically significant difference in the effect of temperature and humidity on toxin contamination levels during storage （P>0.05）. The impact of different processing methods on the contamination levels of the four mycotoxins also showed no significant difference （P>0.05）， and the average processing factors for contamination levels in wheat products were less than 1.Conclusion Alternaria toxins contamination level was limited by temperature and humidity under standardized storage conditions， and the alternaria toxins levels showed a trend of first decrease and then stabilization within 12 months. Meanwhile， processing wheat into products effectively reduced the contamination level of alternaria toxins. The processing factor provide a quantitative basis for evaluating the detoxification or reduction effects of different processing techniques and can provide a reference for risk assessment of Alternaria toxins.

Abstract:Objective To understandthe baseline level of antibiotic residues in drinking water in a city in Guangdong Province and the reduction effect of water treatment technology on antibiotic residues， and to clarify the health risks of exposure to the antibiotic residues.Methods A total of 200 samples， including raw water， flocculation effluent， precipitation effluent， filtered water and finished water， were collected from 10 drinking water enterprises in a city of Guangdong Province. The occurrence of 92 antibiotics in water samples were detected using online solid phase extraction-ultra high-performance liquid chromatography-tandem mass spectrometry.Results The detection rates of antibiotic residues in 5 groups of samples ranged from 0% to 60%， and the sulfonamides were the major detected antibiotics. Therein， a total of 20 antibiotic residues were observed in raw water， including sulfonamides， macrolides， quinolones and chloramphenicol antibiotics， with the concentrations ranging from （0.057±0.003） to （181.419±4.245）ng/L. The occurrence of antibiotic residues and their concentrations observed in the samples of raw water from river were higher than those from reservoir. The water treatment process effectively removed the antibiotic residues from raw water， the removal rate ranged from 39.89% to 78.85%. Consequently， the antibiotic residues were nearly undetectable in finished water samples. However， the antibiotic residues still be detectable in finished water when river water was used as raw water. For the exposure assessment， the results showed that the population posed a higher risk of being exposed to antibiotics through this drinking water.Conclusion Attention should be concerned to the potential risk associated with this finished water.

Abstract:Objective To establish a method for the determination of hexabromocyclododecanes in infant formula using ultra performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS）.Methods The samples were dissolved in water，extracted with acetonitrile， and purified with enhanced matix removal lipid （EMR-Lipid） combined with QuEChERS dispersed adsorbent. The analytes were separated on an ACQUITY UPLC BEH C₁₈ column （2.1×100 mm， 1.7 μm） with water and methanol/acetonitrile （50∶50， V/V） as mobile phases. The target compounds were analyzed by multiple reaction monitoring mode（MRM） and quantified by isotope dilution internal standard method in negative scanning mode.Results The correlation coefficients （r） of three hexabromocyclododecanes were above 0.999 in the range of 0.5-50 μg/L. The detection limits and quantitative limits were in the range of 0.01-0.04 μg/kg and 0.03-0.13 μg/kg， respectively. The recoveries ranged from 92.1% to 100.2%， and the relative standard deviation were 1.2%-3.8%.Conclusion The method is simple， accurate and sensitive， and can be used to detect hexabromocyclododecanes in infant formula.

Abstract:Objective To clarify the prevalence， drug resistance， and epidemiological characteristics of methicillin-resistant Staphylococcus aureus （MRSA） isolated from chicken meat in Hanzhong， and provide useful insights for prevention of foodborne infections.Methods A total of 196 retail chicken samples were collected from Hanzhong for isolation and identification of Staphylococcus aureus and MRSA. Antimicrobial susceptibility testing combined with whole-genome sequencing was used to analyze antimicrobial resistance characteristics， perform sequence typing （ST）， and identify toxin genes. The phylogenetic relationships among MRSA strains identified in this study were analyzed.Results The MRSA detection rate was 18.9% （37/196）. More than 50% of these methicillin-resistant strains showed resistance to penicillin， erythromycin， clindamycin， tetracycline， and gentamicin. A total of four STs ［（ST9 （40.5%， 15/37）， ST59 （37.8%， 14/37）， ST398 （13.5%， 5/37）， and ST5 （8.1%， 3/37）］ were detected. ST9 and ST59 were the dominant clones identified in this study. The ST9 strain exhibited a higher prevalence of enterotoxin gene clusters than the ST59 strain， which carried fewer drug resistance genes but demonstrated a higher prevalence of the immune escape virulence genes sak and scn. Notably， the ST398 strain lacks enterotoxin genes， whereas the ST5 strain harbors the most diverse repertoire of virulence genes. In total， 23 virulence genes were identified. All strains carried the hemolysin genes hlgA， hlgB， hlgC， and the metalloproteinase gene aur. The prevalence of novel enterotoxins was higher than that of traditional enterotoxins. Genes encoding leukocidin and exoproteinases were also identified. The phylogenetic analysis reveals that strains sharing the same ST type are consistently grouped into a single clade within the evolutionary tree.Conclusion The ST9 strain exhibited the highest isolation rate among chicken-associated MRSA in the Hanzhong region between 2019 and 2024， and was characterized by a high prevalence of enterotoxin gene clusters. During this period， the ST59 strain became the predominant clone in retail chickens in this region， with its notably high prevalence of immune escape genes.

Abstract:Objective To retrospectively analyze the specific immunoglobulin E （sIgE） antibody test results of seven inhalant allergens and seven food allergens in children from Hebei Province， and to provide a scientific basis for the prevention and management of allergic diseases.Methods From January 2016 to December 2019， a total of 23 904 children aged 0-14 years in a tertiary hospital in Hebei Province underwent sIgE testing using the immunoblotting method. The test results were statistically analyzed according to allergen type and grade， age group， season， and gender.Results The positivity rate of food allergens in children from Hebei Province was 71.11%， higher than 49.73% for inhalant allergens. Male children showed significantly higher positivity rates than females for most allergens （P<0.01）. For inhalant allergens， positivity rates generally increased with age； for example， ragweed/mugwort was 0.22%， 0.98%， 2.30%， and 3.94% in infancy， toddlerhood， preschool， and school age， respectively （χ2=240.51， P<0.01）. In contrast， for food allergens such as egg white， beef/lamb， and milk， the rates peaked early and then declined， with egg white positivity rates of 19.42%， 38.30%， 35.86%， and 21.25% across the four age groups （χ2=790.19， P<0.01）. Seasonal variation was evident： inhalant allergen positivity was generally higher in summer and autumn， while food allergens showed more fluctuation. For example， mixed dust mites showed 16.52%， 21.95%， 11.91%， and 14.61% positivity in spring， summer， autumn， and winter， respectively （χ2=226.37， P<0.01）， and milk allergen positivity was highest in spring （37.98%， 30.37%， 33.41%， 33.48%； χ2=87.82， P<0.01）.Conclusion From 2016 to 2019， the epidemiological characteristics of allergen sensitization in children from Hebei Province varied according to gender， age， and season. Targeted preventive strategies should be developed based on these characteristics to reduce the incidence of allergic diseases in children.

Abstract:Objective To explore the characteristics of pesticide residues in commercially available vegetables in Wuxi City， and evaluate the dietary exposure risks of residents.Methods One hundred and twenty seven commercially available vegetable samples were randomly selected from 7 monitoring counties （districts） in Wuxi City from 2021 to 2023， and the 51 kinds of pesticide residues were detected using gas chromatography-tandem mass spectrometry （GC-MS/MS） and liquid chromatography-tandem mass spectrometry （LC-MS/MS） and other methods. The exceeded levels were analyzed based on GB 2763—2021.The risk assessment of pesticide residues was evaluated using the index of food safety method and hazard risk coefficient model.Results The total detection rate of pesticide residues in vegetables was 76.38% （97/127）， with a total excess rate of 6.30% （8/127）. The 25 kinds of pesticides were detected， including some prohibited and restricted pesticides. The highest detection rate was dimethomorph （29.13%， 37/127） and the highest excess rate was chlorpyrifos （3.94%， 5/127）. Pesticide residues were detected in all 7 categories of vegetables. The highest detection rate was fresh beans， and the highest excess rate was bulbs， at 100.00% （3/3） and 40.00% （4/10）， respectively. The results of the food safety index method indicated that the overall dietary exposure risk of commercially available vegetables in Wuxi City was within acceptable range， but the IFS_max values of oxadixyl and dithiocarbamates were greater than 1， and there were unacceptable risk. Moreover， the application of chlorpyrifos was considered to be of high risk based on the hazard risk coefficient method， while the applications of dimethoate， cyhalothrin and thiamethoxam were considered to be of medium risk. Based on a synthesis of the two methods， the risk of pesticide residues in commercially available vegetables in Wuxi City was characterized by overall controllability and prominent pollution of specific pesticides.Conclusion The overall dietary exposure risks of pesticide residues in commercially available vegetables in Wuxi City was safe and acceptable， but the risks of illegal use of prohibited and restricted pesticides and multiple pesticide residues were still existed. It is suggested that relevant departments should target and control the potential risks and continue to pay attention to the quality and safety of vegetables.

Abstract:Objective To investigate the content and distribution characteristics of 7 elements in Kuding Tea in Chinese market.Methods The Kuding Tea samples from 20 provinces and cities in China were collected from 2016—2017， and the contents of lead， cadmium， mercury， arsenic， aluminum， chromium and nickel were simultaneously determined by microwave digestion and inductively coupled plasma mass spectrometry. Seven elements were analyzed by Mann-Whitney U test and Kruskal-Wallis test， and the correlation was analyzed by Kendall correlation coefficient.Results The content levels of 7 elements in the large-leaf Kuding Tea from high to low were aluminum， cadmium， nickel， total chromium， total arsenic， lead and total mercury. The content levels of 7 elements in small-leaf Kuding Tea from high to low were aluminum， nickel， lead， total chromium， total arsenic， cadmium and total mercury. The frequency distribution of cadmium， nickel， thousand and total arsenic in large-leaf Kuding Tea was higher than that in small-leaf Kuding Tea， the content of cadmium was about 26 times of that in small-leaf Kuding Tea， the frequency distribution of lead， mercury and total chromium in small-leaf Kuding Tea was higher than that in large-leaf Kuding Tea， and the content of lead was significantly higher than that in large-leaf Kuding Tea. There were regional differences in the content of 6 elements of the two alternative teas， and some elements were correlated.Conclusion There are 7 elements pollution in both large-leaf Kuding Tea and small-leaf KudingTea， and their contents are different and correlated in different regions. There are significant differences in the enrichment ability of key elements such as aluminum， cadmium and lead between the two substitute teas， and their health risks need to be further studied.

Abstract:This paper conducts a comprehensive comparison and analysis of domestic and international standards pertaining to high-risk contaminants in edible vegetable oils， including solvent residues， polycyclic aromatic hydrocarbons， mycotoxins， heavy metals， 3-chloropropanol esters， and glycerol esters. The objective is to establish a scientific foundation for the revision of relevant standards in China. By conducting an in-depth investigation into the sources of these contaminants and systematically sorting and comparing domestic and international standards， the study uncovers inherent discrepancies between China’s standards and those at the international level. The research summarizes the strengths and weaknesses of China’s edible vegetable oil pollutant limit standards and proposes targeted revision suggestions. Ultimately， the findings aim to provide technical support for the enhancement of China’s edible vegetable oil pollutant limit standard system， thereby ensuring the healthy and stable development of the edible oil market.

Abstract:Objective To summarize the characteristics and overall development trends of food labeling trade measures in various countries in the past decades， providing technical reference for national adjustments to food safety supervision measures and trade policies. It also aims to help enterprises going global better understand the dynamics of food labeling trade measures in Regional Comprehensive Economic Partnership （RCEP） member countries， thereby enhancing the level of international competition of Chinese food enterprises.Method Statistical， differentiated， and trend analyses were conducted on the 381 notifications related to food labeling measures submitted by RCEP member countries to the WTO from 2014 to 2023.Results In summary， the food labeling trade measures of RCEP member countries encompass three major characteristics： language barriers， detail and concealment， and high extensibility. Additionally， there are four major development trends： using food labeling trade measures to protect domestic advantaged industries， promoting national food safety regulatory concepts to enhance international influence， innovating nutritional labeling requirements to cultivate healthy eating habits among citizens， and safeguarding consumers’ right to know to deeply enhance humanistic care.Conclusion Suggestions are made to support national health and the sustainable high-quality development of China’s food industry under the RCEP agreement by： （1） reasonable food labeling rules should be formulated， （2） construct a database of food labeling regulations and promote the development of an AI-based food labeling system，（3）establish a risk early warning mechanism for food technical trade measures， and make full use of the Special Trade Concerns （STC） mechanism， and （4） formulating intuitive and easy-to-understand guidelines for nutritional labeling.

Abstract:Objective Analysis of the antimicrobial resistance characteristics， molecular characteristics， and homology of Staphylococcus aureus， the source of two cases of food poisoning in Nan’an District， Chongqing Municipality.Methods Pathogens were isolated and identified from anal swabs of cases and practitioners， samples of the food processing environment and retained food. The isolates were subjected to enterotoxin detection， virulence gene detection（qPCR）， antimicrobial susceptibility testing， and whole genome sequencing was performed to obtain virulence and resistance genes carried by the isolates and to perform multilocus sequence typing and single nucleotide polymorphism analysis.Results Ten S. aureus strains were isolated from anal swabs of eight cases， one environmental sample， and one retained food sample， of which four and six strains were isolated from A and B incidents， respectively. In the same incident， S. aureus produced the same enterotoxin with the same resistance profile. Using the qPCR method， the virulence genes of the S.aureus strains producing SEA and SEE were identified； the results showed that sea， seb， sec， and sed were positive. Using the gene annotation technique， the S.aureus producing SEA and SEE were discovered to have the virulence gene sea. By using qPCR and gene annotation approaches， it was demonstrated that the virulence genes sea and seb were positive for strains producing SEA， SEB， and SEE. the resistance profiles were PEN-ERY and PEN respectively. The isolates with resistance profiles PEN-ERY， all carried the associated resistance genes blaZ and erm（A）except for one isolate that did not carry the associated resistance gene blaZ， whereas the isolates with resistance profiles PEN all carried the associated resistance gene blaZ. The plasmid replicons carried by the isolates were mainly rep16， rep19， rep5a. MLST analysis showed 100% homozygosity for the same incident， and MLST typing of S. aureus for the two incidents was ST30 type and ST59 type respectively. Single nucleotide polymorphism analysis of the same incident was highly homologous.Conclusion Therefore， these two events were both food poisoning events caused by S. aureus contamination. it is necessary to further strengthen the education and management of restaurants. S. aureus strains were resistant to penicillin. Based on whole genome sequencing， multilocus sequence typing and single nucleotide polymorphism analysis of the strains can be used for homology analysis of aggregation incidents caused by S. aureus.

Abstract:Sarcopenia is an age-related progressive disease that increases the risk of falls， disability and death in the elderly， and brings a heavy economic burden to families and society. At present， nutritional supplementation is the main prevention and treatment of sarcopenia. Studies have confirmed that leucine and its metabolite β-hydroxy-β-methylbutyrate（HMB） can promote muscle protein production and inhibit muscle protein degradation， which is a key nutrient in sarcopenia formula foods. However， the optimal dose-response relationship is still unclear. This paper focuses on the key role of leucine and HMB in sarcopenia and its application in sarcopenia formula foods.

Abstract:Pyrrolizidine alkaloids （PAs） are a class of naturally occurring toxic compounds widely distributed in plants， primarily transmitted and bioaccumulated through the food chain. They have been detected in various food products including tea， honey， cereals， and traditional herbal medicines. The contamination levels of PAs exhibit regional and interspecies variations influenced by multiple factors， with their toxicity predominantly manifesting as hepatotoxicity and carcinogenicity. Chronic health risks may arise from prolonged exposure to these compounds. Currently well-established detection methodologies include thin-layer chromatography （TLC）， gas chromatography-mass spectrometry （GC-MS）， and liquid chromatography-mass spectrometry （LC-MS）. This review aims to explore current research progress regarding contamination levels， analytical techniques， and risk assessment of PAs in food matrices. In conclusion， PAs contamination poses a latent threat to food safety and public health， necessitating intensified research into contamination mechanisms， long-term exposure risks， and advanced detection technologies to formulate more effective preventive strategies.