Objective To compare the mold counting effects of potato dextrose agar and rose Bengal agar as 2 types of counting culture medium. Methods Growth rate, specificity, and selectivity were compared between potato dextrose agar and rose Bengal agar culture medium using 20 kinds of standard mold strains and 15 kinds of common foodborne pathogen strains. Additionally, the counting effects of both culture medium were assessed using 36 actual food samples and 174 swab samples from food contact environments in refrigerators. Results The growth rate (PR value) of the 20 kinds of mold strains on both potato dextrose agar and rose Bengal agar culture medium was greater than 0.7, and the selectivity (G value) was less than 1. However, molds on potato dextrose agar culture medium exhibited more typical colony morphology, indicating better specificity than rose Bengal agar culture medium. In the detection of actual samples, the detection rate of potato dextrose agar culture medium was relatively high, showing a significant difference compared to rose Bengal agar culture medium (χ²=13.551, P=0.001). It exhibited a particularly higher detection rate in samples with low contamination (χ²=9.929, P=0.001). However, for highly contaminated samples, rose Bengal agar culture medium was more convenient for counting. Conclusion Using a single culture medium can affect counting results. It is recommended to apply 2 types of culture medium or select an appropriate counting medium based on the contamination level when conducting mold counting tests on food samples.

Objective To explore the contents of 7 kinds of elements in agricultural products in a certain area in North China plain, including lead (Pb), cadmium (Cd), mercury (Hg), arsenic (As), tin (Sn), nickel (Ni) and chromium (Cr), and evaluate the safety risks of dietary ingestion. Methods The samples were pretreated by microwave digestion, and the contents of 7 kinds of heavy metals in 611 agricultural products collected in the certain area from 2022 to 2024 were determined by inductively coupled plasma mass spectrometry (ICP-MS). Index (P_i), Nemero comprehensive pollutant index (P_N) and target hazard quotient/total target hazard quota (THQ/TTHQ) were used to evaluate the pollution levels of heavy metals in agricultural products. Results All elements except Hg were detected in the agricultural products. Among them, the content of Pb and Cr in individual samples exceeded the limit values specified in GB 2762—2022 National food safety standard-Limits of contaminants in foods (Pb≤0.2 mg/kg, Cr≤0.5 mg/kg). The overall content levels of the 7 kinds of elements were relatively low, and their order in the agricultural products was Ni (0.192 mg/kg)>Cr (0.040 mg/kg)>Pb (0.017 mg/kg)>Sn (0.011 mg/kg)>As (0.009 mg/kg)>Cd (0.005 mg/kg), the heavy metal content of agricultural products in different types and regions was quite different, and the THQ/TTHQ of all agricultural products was less than 1, and the P_i and P_N were less than 1. Conclusion The quality and safety of agricultural products in the study area are in good condition, and the level of heavy metal pollution is relatively low. However, there may be potential heavy metal exposure risks in some individual villages and towns in the southeastern part, and the dietary exposure risks for children are greater than those for adults.

Objective To investigate the extent of lead contamination in commercial foods and assess the health risk from dietary lead intake of the residents in Guangzhou in 2023. Methods In 2023, the 310 samples were collected from 3 food categories in 11 districts of Guangzhou, China. Lead was measured in the samples using inductively coupled plasma mass spectrometry. Dietary exposure to lead was calculated based on the food consumption survey of Guangzhou residents in 2011, and the health risk of the population was evaluated using the margin of exposure (MOE) method. Results Lead was detected in 83.23% of the overall samples, and the over-standard rate was 0%, with an average lead content of 0.040 mg/kg. The highest lead level was found in bivalves, 0.205 mg/kg. The average daily dietary lead exposure of the whole population and all age groups (3-6 years old, 7-17 years old, 18-59 years old, and 60 years old and above) in Guangzhou and the consumers with high dietary exposure of all age groups (95th percentile P₉₅) were: 0.082, 0.120, 0.097, 0.078, 0.081 μg/(kg·d) and 0.225, 0.330, 0.268, 0.206, 0.226 μg/(kg·d). The contribution of rice and rice products, brassica vegetables, and leafy vegetables to dietary lead exposure was relatively significant. The MOE values for lead in residents of all age groups were greater than 1, with the MOE values for minors being lower than those for adults, particularly among high dietary exposure populations. Conclusion In 2023, there is a certain degree of lead contamination in the food items under close watch in the Guangzhou market. The average dietary lead exposure of residents of all age groups is within the acceptable range. However, it is still necessary to pay attention to key food items and take measures to reduce the dietary lead exposure risk for residents in Guangzhou.

Objective To evaluate the dietary exposure levels of lead, cadmium, arsenic and chromium in Triticum aestivum L. in Anhui Province in 2023 and to evaluate dietary health risks combined with population consumption. Methods A total of 212 Triticum aestivum L. samples collected from Anhui Province in 2023 were analyzed for plumbum, cadmium, arsenic, and chromium content using inductively coupled plasma mass spectrometry (ICP-MS). The contamination status of the 4 kinds of elements was evaluated using the contamination index method. The margin of exposure (MOE) was used for plumbum exposure assessment, while the provisional tolerable monthly intake (PTMI) or benchmark dose level (BMDL) compared with dietary exposure, expressed as the margin of safety (MOS), was applied for cadmium and arsenic exposure assessment. For chromium, the dietary exposure (EXP) was calculated as a percentage of the tolerable daily intake (TDI). Results Among the 212 Triticum aestivum L. samples, As levels did not exceed the standard limits. The exceedance rates for cadmium, plumbum, and chromium were 1.89%, 1.42% and 7.55%, respectively. The single-factor contamination index for all elements was less than 1, indicating safety, while the comprehensive contamination index was 1.737, suggesting mild contamination. The average dietary exposure levels of plumbum, cadmium, and arsenic for residents of different age groups and cities in Anhui Province showed MOE and MOS values greater than 1, and the EXP/TDI percentage for chromium was less than 1. However, for high-exposure P_97.5 populations, including children aged 13-36 months and 7-12 years, the EXP/TDI percentage for chromium exceeded 1. Similarly, in northern Anhui cities such as Fuyang, Huaibei, and Suzhou, the EXP/TDI percentage for Cr in high-exposure P_97.5 populations also exceeded 1. Conclusion The exposure risk levels of plumbum, cadmium, arsenic, and chromium from Triticum aestivum L. consumption among Anhui residents are generally acceptable. However, special attention shall be given to children, adolescents, and high-exposure populations in Fuyang, Huaibei, and Suzhou.

Objective To investigate the contamination status and conduct a risk assessment of foodborne pathogens in food samples from Baotou City, Inner Mongolia, from 2016 to 2023. Methods According to the requirements of the Inner mongolia autonomous region food safety risk monitoring plan—Microbiological monitoring, food samples were collected from 10 counties and districts in Baotou City between 2016 and 2023. Detection of foodborne pathogens was performed following standard operating procedures. Results Over the 8-year period, a total of 1358 food samples from 17 major categories were collected, and 485 strains of pathogenic microorganisms belonging to 14 species were detected, with an overall detection rate of 26.58% (361/1358). Among the 11 categories of food samples with detected pathogens, meat and meat products, as well as aquatic products and their products, showed higher detection rates of 42.35% (227/536) and 47.78% (43/90), respectively. Food samples from sampling points such as farmers' markets and farming sites were heavily contaminated, with detection rates of 42.13% (75/178) and 61.22% (30/49), respectively. Among the pathogens, Vibrio alginolyticus and Campylobacter had higher detection rates of 40.00% (8/20) and 50.22% (113/225), respectively. The positive detection rate of monitored samples increased annually, rising from 1.05% (2/190) in 2016 to 50.00% (100/200) in 2023. Conclusion The contamination level of foodborne pathogens in meat and meat products, as well as aquatic products and their products, is relatively high in Baotou City. Sampling points such as farmers' markets pose a risk of causing foodborne diseases.

The popularization of the concept of health in the new era has made the public extremely concerned about food safety. As an important factor affecting food safety, multi-pesticide residues have become the focus of attention for dietary consumers. This paper focused on the cumulative dietary exposure risk of multi-pesticide residues and reviewed the research progress in this field at home and abroad, covering aspects such as assessment frameworks, assessment methods, assessment software and databases. Secondly, it discussed and analyzed the differences in the cumulative dietary risk assessment systems of different international organizations and countries as well as the latest research methods at home and abroad, such as the introduction of advanced data analysis technologies and the adoption of multidisciplinary research models, to comprehensively assess the cumulative dietary exposure risk of multi-pesticide residues. Thirdly, it clarified the importance of relevant databases and software in the assessment process and pointed out the difficulties in data grouping, acquisition and standardization in the current risk assessment research. Finally, it putted forward reasonable suggestions in view of the current situation and existing problems of the cumulative dietary risk assessment of multi-pesticide residues, aiming to provide theoretical support for food quality and safety and the green development of pesticides in the new era.

Objective To establish a method for the simultaneous determination of 24 kinds of β-blockers in eggs by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods The 80% acetonitrile aqueous solution was used as extraction solvent, QuEChERS was used as purification method, acetonitrile-saturated n-hexane was used for degreasing, Waters ACQUITY UPLC BEH C₁₈ (2.1 mm×100 mm, 1.7 μm) column was used for gradient elution with acetonitrile-0.1% formic acid solution as mobile phase. The ionization mode was spray positive ion mode, and quantitative analysis was performed using multiple reaction monitoring mode. The quantitative method was external standard. Results The 24 kinds of β-blockers in eggs showed a good linear relationship (r≥0.9963) in the concentration range. When the sample weight was 1 g (accurate to 0.001 g) and the final volume was 2 mL, the limit of detection was 3 μg/kg, and the limit of quantitation was 10 μg/kg. The average recoveries were 63.6%-108.0%, and the relative standard deviations (n=6) were 0.9%-7.4%. Conclusion This method has the advantages of simple operation, high accuracy, high sensitivity and good reproducibility, and can provide technical reference for the analysis of β-blocker in fresh eggs in daily life and sports events.

Objective To establish an analytical method for the determination of 146 kinds of pesticide residues in animal derived foods by enhanced matrix removal-lipid dispersion solid phase extraction (dSPE EMR-Lipid) and purification technology coupled with gas chromatography-tandem mass spectrometry (GC-MS/MS). Methods The 5 g sample were added to 2 mL ultrapure water, extracted with acetonitrile, freezed for 10 min, separated with QuEChERS EN-extraction package, cleaned-up with dSPE EMR-Lipid, then was detected by GC-MS/MS in dynamic multi-reaction monitoring (DMRM) mode. The analytes were quantified by matrix-matched standard curve method. Results The results showed that 146 kinds of pesticides had good linearities in the concentration of 5-320 μg/L, the linear correlation coefficient of the compounds were greater than 0.9939, and the limits of detection of the method were 0.04-10.91 μg/kg, the limits of quantification were 0.11-32.72 μg/kg. The average recoveries of 146 kinds of pesticides at the spiked level of 0.01, 0.02 and 0.10 mg/kg ranged from 61.3% to 119.3%, relative standard deviations were 0.15%-16.02%. Conclusion The method is simple in pre-treatment, convenient in operation, rapid, sensitive and accurate in detection, can meet the simultaneous detection requirements for multiple pesticide residues. It is suitable for preliminary screening and quantitative detection of multiple pesticide residues in animal derived food.

Objective To establish a quantitative analysis of multi-components by single marker (QAMS) method for the simultaneous determination of 9 kinds of components in Andrographis paniculata. Method The relative calibration factors of andrographolide with forsythitin, oleanolic acid, caffeic acid, andrographolide, dehydrated andrographolide, andrographolide, deoxyandrographolide, dehydrated andrographolide half succinate and sodium bisulfite were established by ultra performance liquid chromatographolide-tandem mass spectrometry. The relative correction factor was used to calculate the content of each component, and the calculated results of QAMS method were compared with the measured values of external standard method. Results The relative correction factors showed good reproducibility, and there was no significant difference between the results obtained by the QAMS method and the external standard method. Conclusion The QAMS method is suitable for the simultaneous determination of 9 kinds of components in Andrographis paniculata, ensuring the reliability of quality.

Objective To develop a method for analysis of 20 kinds of macrolides and lincomasides in mutton by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods Samples were initially extracted with acetonitrile, and the supernatant was concentrated to near dryness. The residues were further extracted with 50% methanol, and the 2 extracts were combined and diluted with a weak alkaline buffer solution (pH 8.0). The mixture was then concentrated and purified using an HLB solid-phase extraction cartridge. A methanol/5 mmol/L ammonium acetate solution (1:1, V:V) was used for final dilution. Detection was performed in positive ion multiple reaction monitoring mode. A matrix-matched standard curve was prepared for quantification. Chromatographic and mass spectrometry parameters were optimized for the 20 kinds of target compounds, while the effects of different mobile phases, extraction solvents, and purification methods on extraction efficiency and purification quality were thoroughly investigated. Results The 20 kinds of macrolides and lincomasides demonstrated excellent linearity within their respective ranges, with correlation coefficients (r²) exceeding 0.999. Recoveries ranged from 64.7% to 94.2%, the relative standard deviation was between 3.8% and 11.0%. Conclusion The developed method is sensitive, accurate, and suitable for the simultaneous detection of 20 kinds of macrolides and lincomasides in mutton.