To analyze the residual status of 7 kinds of antibiotic veterinary drugs in commercially available animal-derived prepared dishes collected from 7 districts of Beijing in 2024, and assess the dietary exposure risks induced by veterinary drug residues via consumption of animal-derived prepared dishes.

A total of 160 samples of commercially available animal-derived prepared dishes were collected from 7 districts in Beijing, and the residual concentrations of 7 kinds of antibiotic veterinary drugs were determined. The mean values, maximum values, P₅₀, P₇₅ and P_97.5 were calculated. Combined with the recommended intakes of livestock, poultry and aquatic products for different age groups specified in the Dietary guidelines for Chinese residents (2022) and the consumption data of livestock, poultry and aquatic products among Beijing residents, the point estimation method was adopted to conduct dietary exposure risk assessment.

Lomefloxacin and norfloxacin were not detected. Enrofloxacin, ciprofloxacin, ofloxacin, pefloxacin and doxycycline were detected at varying levels, with detection rates of 18.8%, 5.6%, 3.2%, 0.6% and 31.2%, respectively. The dietary exposure levels of enrofloxacin+ciprofloxacin, doxycycline and ofloxacin via animal-derived prepared dishes for populations of different age groups ranged from 0.0007 to 0.3312 μg/(kg·BW). The risk quotients calculated based on mean and maximum residues were between 0.0001 and 0.0534, and the hazard indices ranged from 0.0017 to 0.0051.

The health risks from intake of the 7 kinds of antibiotic veterinary drugs through animal-derived prepared dishes are low for populations of different age groups in Beijing.

To establish a method for simultaneous detection of 7 kinds of important foodborne pathogens, including Vibrio parahaemolyticus, Vibriocholerae, Salmonella, Staphylococcusaureus, Escherichiacoli O157, Listeria monocytogenes and Campylobacter jejuni by high-throughput and rapid detection method based on Luminex xMAP liquid-phase microarray technology.

Specific genes of the 7 kinds of pathogens, namely TLH, gspD, invA, nuc, rfbE/eae, hlyA and hipO, were selected as detection targets, and specific primers tagged with TAG sequence and biotin were designed and synthesized. The multiplex polymerase chain reaction (PCR) amplification system and suspension array hybridization conditions were optimized, and the specificity, sensitivity and repeatability of the method were systematically evaluated. A total of 172 clinically isolated strains were used for practical application verification.

All 7 kinds of target pathogens showed specific amplification without cross-reaction with non-target strains. Double log linear regression analysis of median fluorescence intensity values of the 7 kinds of pathogens at concentrations ranging from 10¹ to 10⁵ CFU/mL, showed an extremely significant positive correlation between bacterial concentration and median fluorescence intensity value (R²>0.994, P<0.001), with a slight species-specific slope. The quantitative limits of detection of PCR was 10² CFU/mL, and the qualitative limit of detection was close to 10¹ CFU/mL. The intra-assay coefficient of variation (CV) of the 7 kinds of pathogens at low, medium and high concentrations were 0.9%–4.6%, 0.4%–2.3% and 0.1%–0.8% respectively; the inter-assay CV were 1.5%–4.8%, 0.2%–1.7% and 0.1%–0.9% respectively, indicating excellent intra-assay precision and inter-assay stability.The total coincidence rate of detection for 172 clinically isolated strains was 96.5%. Modified Kappa consistency test showed that the overall Kappa coefficient was 0.928 (P<0.001), and the Kappa value of each pathogen was no less than 0.8, proving that the method had reliable positive detection consistency without systematic deviation, and could meet the accuracy requirements of clinical detection and food safety monitoring.

The Luminex xMAP liquid-phase microarray assay established in this study has the advantages of high specificity, high sensitivity, high throughput, rapidity and stability. It can realize simultaneous screening of 7 kinds of foodborne pathogens, and is suitable for food safety monitoring, emergency disposal of food poisoning and rapid clinical detection.

To evaluate the genotoxicity and in vitro hypolipidemic activity of docosahexaenoic acid-eicosapentaenoic acid-rich oil from Schizochytrium (DHA-EPA SO) (DHA content: 37.33%±0.15%; EPA content: 5.82%±0.03%), clarify its safety and functional properties.

Using the bacterial reverse mutation assay, mammalian erythrocyte micronucleus test and mouse spermatocyte chromosome aberration test, the genotoxicity of DHA-EPA SO was systematically evaluated. Using 3T3-L1 preadipocytes as the cell model, the in vitro hypolipidemic activity of DHA-EPA SO was investigated via qualitative observation by oil red O staining, quantitative analysis of optical density value, and determination of intracellular triacylglycerol (TG) and total cholesterol (TC) content.

Within the test dose range, DHA-EPA SO presented negative results in 3 genotoxicity assays. In the bacterial reverse mutation assay, the number of revertant colonies of each strain did not exceed twice that of the negative control group; the micronucleus rate of mouse bone marrow erythrocytes and the chromosome aberration rate of mouse spermatocytes showed no significant differences compared with the control groups (P>0.05), indicating no mutagenicity or genetic damage risk of DHA-EPA SO. The in vitro hypolipidemic tests demonstrated that DHA-EPA SO could effectively inhibit lipid accumulation in 3T3-L1 cells and reduce intracellular TG and TC content, exerting the optimal hypolipidemic effect at a mass concentration of 12.50 μg/mL, while the hypolipidemic activity was attenuated with increased doses.

DHA-EPA SO has no genotoxicity and exhibits significant in vitro hypolipidemic activity, which endows it with broad application prospects in the field of functional foods and health products.

To understand the community structure, diversity and potential function of lactic acid bacteria in pickled vegetables in Yunnan Province.

The 30 traditionally pickled vegetables samples collected from 5 different climatic and geographical regions in Yunnan Province, and sequenced by Oxford Nanopore high-throughput sequencing technology.

The results revealed that within the class Bacilli, a total of 1 order, 5 families, 10 genera and 70 species were annotated. At the genus level, Lactobacillus was the absolutely dominant genus, with its relative abundance ranging from 66.13% to 96.92%, followed by Enterococcus, Leuconostoc, Pediococcus and Weissella. At the species level, Lactobacillus fermentum, Companilactobacillus alimentarius, Lactobacillus delbrueckii, Enterococcus faecalis and Levilactobacillus koreensis were identified as the dominant species, with significant differences in species composition across regions. Samples from the tropical regions of Xishuangbanna Dai Autonomous Prefecture and Dehong Dai and Jingpo Autonomous Prefecture exhibited higher lactic acid bacteria diversity than those from the more temperate regions of Kunming, Qujing and Dali Bai Autonomous Prefecture. Cluster analysis showed that tropical samples grouped together, while temperate samples formed a separate cluster, indicating that climate and geographical origin were major factors influencing lactic acid bacteria community composition. Functional prediction indicated that chemoheterotrophy and fermentation were the primary energy metabolism pathways. Regional differences were observed in functions such as nitrite reduction, ammonification and nitrogen respiration. In the samples from Dali Bai Autonomous Prefecture, the abundance values of chemoheterotrophy and fermentation functions showed a positive correlation with the total acid content, both being the highest. In contrast, Xishuangbanna Dai Autonomous Prefecture and Dehong Dai and Jingpo Autonomous Prefecture were characterized by higher abundance values of nitrate reduction function and higher nitrite content.Meanwhile, in Qujing and Kunming areas, the abundance values of nitrite ammonification and nitrogen respiration functions were higher, and their nitrite content showed a negative correlation with these functions, being significantly lower than that in other regions.

This study reveals the community differences, diversity and potential functions of lactic acid bacteria in pickled vegetables from different regions of Yunnan Province, providing a theoretical basis for the subsequent screening of functional strains and the development and utilization of regional characteristic lactic acid bacteria resources.

To establish rapid prediction models for multiple nutritional component indexes in nanostructured lycopene liquid beverages by near-infrared spectroscopy (NIRS) combined with chemometrics.

NIRS coupled with partial least squares regression (PLSR) was adopted, and a combined pretreatment optimization strategy was proposed. Rapid quantitative analysis models were constructed separately for key indexes including lycopene, soluble solids, acidity and moisture content in 3 types of samples: lycopene liquid stock solution, nanostructured mannan-modified lycopene liquid beverage and nanostructured dextran-modified lycopene liquid beverage. Model performance was comprehensively evaluated byroot mean square error (RMSE), residual predictive deviation (RPD) and relative error ratio (RER).

After optimized by combined pretreatment, the multi-index quantitative models of the 3 kinds of nanostructured lycopene liquid beverages all showed favorable predictive performance. The model of lycopene liquid stock solution was the best overall, with the test set RMSE of 0.9279, RPD of 5.3659 and RER of 18.3682; the test set RPD of the model for nanostructured mannan-modified samples were 4.7333, respectively; the test set RPD of the model for nanostructured dextran-modified samples were 3.4823, respectively. All models had RPD greater than 3.0, with high prediction accuracy and strong stability, which could realize the simultaneous and rapid quantification of lycopene, soluble solids, acidity and moisture content.

In summary, NIRS combined with chemometrics can effectively detect multiple key indexes in nanostructured lycopene liquid beverages, meet the demand for rapid detection in actual production, and provide efficient technical support for the quality control of such products.

To evaluate the pollution characteristics of heavy metals in vegetables from Qingpu District, Shanghai and analyze the risk of dietary intake.

A total of 809 vegetable samples from 6 major vegetable categories were continuously collected over 3 years from 2022 to 2024. The content of total arsenic, total mercury, lead and cadmium were determined by microwave digestion and inductively coupled plasma mass spectrometry. The pollution levels were assessed using the single-factor pollution index (P_i) and Nemerow comprehensive pollution index (P_N). The health risks of dietary intake were evaluated using the target hazard quotient(THQ) and total target hazard quotient (TTHQ).

The detection rate of heavy metals in 809 vegetable samples was 80.2%. The detection rates of the 4 kinds of heavy metals ranked in descending order: cadmium>total arsenic>lead>total mercury, their average content were ranked as lead (0.0408 mg/kg)>cadmium (0.0182 mg/kg)>total arsenic (0.0123 mg/kg)>total mercury (0.0013 mg/kg). All samples complied with the limits specified in GB 2762—2022 National food safety standard-Contaminant limits in food, with all P_i<1. The P_N of different vegetable categories was all less than 0.7, and the order was solanaceous vegetables=onion and garlic vegetables>cucurbit vegetables>aquatic vegetables>leafy vegetables>cabbage vegetables. The single heavy metal THQ from high to low was total arsenic>cadmium>lead>total mercury. Overall, the order of TTHQ for different vegetable categories was leafy vegetables>cucurbit vegetables>cabbage vegetables>onion and garlic vegetables>aquatic vegetables>solanaceous vegetables. The TTHQ for both adults and children was less than 1.

The vegetables produced in Qingpu District of Shanghai are not contaminated by total arsenic, total mercury, lead and cadmium, and are at a safe level. There is no significant health risk to the study population from dietary intake of these 4 kinds of heavy metals in vegetables.

To establish a method for determination of 48 kinds of pesticide and veterinary drug residues in crayfish by pass-through purification coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).

The samples were first extracted using a 80% acetonitrile solution, and then cleaned-up by hydrophilic-lipophilic column in a pass-through mode and filtered through a filter, then separated employing an C₁₈ column. The mass spectrometer operated with electrospray ionization in multiple reaction monitoring mode and quantified by matrix-matched external standard curve method.

The results demonstrated that all the analytes had satisfactory linearity in the range of 1–100 ng/mL with correlation coefficients (r) greater than 0.997. The limits of detection and the limits of quantitation were in the ranges of 0.02–0.20 and 0.05–0.50 μg/kg, respectively. The average recoveries at 3 spiked levels with 6 parallel determinations ranged between 70.2%–105.8%, with the relative standard deviations no more than 3.3%, which met the requirements of trace analysis. The 36 samples from major producing areas were analyzed, revealing a drug detection rate of 20.8%. The positive results showed high consistency when retested against standard methods.

This method is simple, rapid, sensitive and accurate, effectively reducing matrix interference from the complex composition of crayfish. It satisfies the screening requirements for pesticide and veterinary drug residues in crayfish under the rice-crayfish integrated farming model, providing a crucial technical tool for quality safety control and risk assessment.

To assess the health risks to consumers from pesticide residues in Apium graveolens in Hainan Province.

A total of 162 batches of Apium graveolens samples were obtained in Hainan Province during the period from 2019 to 2024, and the QuEChERS extraction method combined with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and gas chromatography-tandem mass spectrometry(GC-MS/MS) were employed for determining the residues of 38 kinds of pesticides in Apium graveolens samples. The point assessment method was used to study the chronic and acute dietary risk assessment of a single pesticide for adults and children in terms of health risks; further research was conducted on the cumulative toxic effects of the pesticide.

A total of 21 pesticides were detected with a detection rate of 87.0%. A maximum of 14 kinds of pesticides were detected in one sample. The chronic and acute dietary risks of single pesticides were less than 1 for both adults and children, and it posed no risk to either adults or children. The cumulative risk values of endocrine-disrupting pesticides, skin-irritating pesticides, reproductive toxic and neurotoxic pesticides for both adults and children were all less than 1, and the safety risk could be ignored.

With Hainan Province vigorously promoting the traceability system for agricultural product quality and safety and green control technologies, and guiding farmers to follow good agricultural practices for pesticide use, the risk of pesticide residues in Hainan’s agricultural products such as Apium graveolens has been effectively controlled, ensuring the quality and safety of the products.