Objective To evaluate the heavy metal contamination characteristics and health risks of Ziziphus jujuba Mill. from 3 major production regions (Jiao cheng Jun Ziziphus jujuba Mill., Tai gu Hu ping Ziziphus jujuba Mill., and Xiang fen Guan tan Ziziphus jujuba Mill.) in Shanxi Province. Methods Sample pretreatment was performed using a microwave digestion system, followed by quantitative analysis of Cr, Ni, Pb, Cd, As, and Hg in 180 Ziziphus jujuba Mill. samples via inductively coupled inductively coupled plasma-mass spectrometry (ICP-MS). Experimental data were standardized using Microsoft Excel 2022, and non-parametric statistical analyses (Kruskal-Wallis H test, Spearman’s rank correlation) were conducted with SPSS 26.0 IBM to investigate elemental distribution patterns and regional correlations. Health risks were assessed using the United States Environmental Protection Agency (USEPA) model with exposure parameters. Results A highly sensitive multi-element simultaneous detection method was established with a limit of detection of 0.003 to 0.010 mg/kg, with a recovery rates of 92% to 108% and a precision of 2.9% to 4.5%. Key findings included: (1) Hg was undetected in all regions, while Cr and Ni were universally detected, Pb detection rates exhibited regional differences, with the highest in Xiangfen, Cd detection rates were notably higher in the Taigu; (2) The studied elements exhibited significant spatial heterogeneity; (3) Pb, Ni and Cr in Jiao cheng Jun Ziziphus jujuba Mill. and Xiang fen Guan tan Ziziphus jujuba Mill. exhibited a highly significant positive correlation, while the correlations of the same elements between Tai gu Hu ping Ziziphus jujuba Mill. and Xiang fen Guan tan Ziziphus jujuba Mill. showed a synchronous enhancement; (4) health risk assessment identified potential non-carcinogenic risks for Cr and Pb in Xiangfen, and the daily intake of As approached but remained below the international threshold. Conclusion This study systematically map the heavy metal contamination profile of Shanxi Ziziphus jujuba Mill. for the first time and propose region-specific grading standards for pollutants, providing a scientific basis for improving the quality and safety regulatory framework of jujube products.

Objective To develop an enzyme-linked immunochromatographic test strip for the determination of amanita toxin in mushroom based on immunochromatography. Methods N-hydroxysuccinimide (NHS) and N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride (EDC) were used as activators, 6-aminohexanoic acid was introduced to obtain amanitin peptide hapten, and further conjugated with keyhole limpet hemocyanin (KLH) and bovine serum albumin (BSA) to prepare immunogen and coating antigen. Then, the immunogen was used to immunize Balb/c mice to prepare monoclonal antibodies. The colloidal gold immunochromatographic test strip for amanitin was successfully developed by preparing colloidal gold and gold labeled antibody, optimizing the concentration of coating antigen, secondary antibody and extracting solution, and then its cross reactivity, stability, repeatability, and accuracy were evaluated. Results The limits of detection of α-amatoxin, β-amatoxin, and γ-amatoxin peptide were 100, 20 and 50 μg/kg, respectively. The sensitivity was 100%, the false positive rate and false negative rate were 0%, and the results were consistent with the existing instrumental methods without cross reaction with other mushroom toxins. Conclusion The test strip has the characteristics of simple operation, high repeatability and good stability, and is suitable for on-sites creening and rapid detection of amanitin in mushrooms.

Objective To study of the quality, safety and authenticity analysis of beef jerky in Inner Mongolia region. Methods This study used 114 beef jerky samples from 7 categories of food supervision and sampling inspection and enterprise entrusted inspection in Inner Mongolia region 2017 to 2024 as experimental samples, and used 23 national food safety standards to comprehensively analyze their nutritional components, heavy, food additives, veterinary drug residues, microorganisms, animal source and other 23 quality and safety parameters. Results The protein content and energy of 114 samples of Inner Mongolia beef jerky were (44.26±7.19) kJ/100 g and (1450.13±536.11) kJ/100 g, respectively, but the content of fat and moisture varied greatly, the fat content of Y-2 fried beef jerky and Y-5 fat and lean beefky was significantly higher than other samples, and the moisture content of Y-2 fried beef jerky was significantly lower than other samples lead (detected in 6/25 samples), chromium (detected in 22/25 samples), cadmium (detected in 2/25), nitrite (detected in 5/18 samples), benzoic acid (not in all 37 samples), sorbic acid (detected in 2/37 samples), sodium diacetate (detected in 4/37 samples), carmine (not detected in all 18 samples), sodium saccharin (not detected in all 20 samples), clenbuterol (not in all 19 samples), ractopamine (not detected in all 19 samples), salbutamol (not detected in all 10), total bacterial count (50 samples, 9 of which were less than 10 CFU/g, and 3 were greater than 10⁴ CFU/g), and coliform group (all 50 samples were <10 CFU/g) were all in compliance with the limit requirements of the National Food Safety Standards; 12 samples tested were found to be of bovine origin, and no porcine origin detected. Conclusion The beef jerky in Inner Mongolia has the characteristics of high protein and high energy, and the heavy metal, food additives, veterinary drug residues, microbial indicators all meet the national food safety standards and there is no pork adulteration, showing a high level of quality safety. The moisture and fat content vary greatly which may be related to the processing technology of frying, roasting and air-drying of Inner Mongolia beef jerky and the raw materials.

Objective To establish a rapid competitive inhibition immunochromatographic detection method for the simultaneous determination of 3 kinds of neonicotinoid pesticides with a high non-compliance rate in Musa nana Lour.. Methods The samples were extracted using a solution composed of 20% methanol, 0.05% Tween, and 0.02 mol/L phosphate-buffered saline (PBS). After centrifugation at 8000 r/min for 5 min, 100 μL of the supernatant was taken and diluted according to specific dilution ratios. Subsequently, 100 μL of the diluted sample solution was added to the sample well (S). The results were read after 8 min reaction period. Results The limits of detection for imidacloprid, clothianidin, and thiamethoxam were 0.050, 0.020 and 0.002 mg/kg, respectively, with corresponding sample dilution factors of 2-fold, no dilution, and 5-fold. Upon evaluation, the relative accuracies were determined to be 96.7%, 98.3% and 100.0%, respectively, which were in agreement with the results obtained by the liquid chromatography-mass spectrometry method for the detection of these pesticides in Musa nana Lour.. Conclusion This rapid detection method exhibits characteristics such as simplicity in operation, rapidity in detection, and portability of the instrument, rendering it suitable for on-site and rapid screening of pesticide residues in Musa nana Lour..

Objective To evaluate the diazepam rapid detection products of 5 manufacturers with high recognition in Beijing. Methods In this study, common carp, grass carp and crucian carp were used as the substrate for technical evaluation from the aspects of sensitivity, HOOK effect, specificity, accuracy and ease of operation, etc. The evaluation results were referred to the Notice on the field verification of rapid detection products for drug residues in aquatic products in 2023 issued by the Chinese Academy of Fishery Sciences. Results The limits of detection for sensitivity of company I-V were 92.2%, 88.9%, 100.0%, 65.6% and 33.3%, respectively. Company II HOOK effect false negative 10%; HOOK effect did not appear in the other 4 companies. The cross-reaction rate of company III to the residues of 4 kinds of common veterinary drugs was as high as 60% to 90%, the cross-reaction rate of company II to enrofloxacin was 10%, the cross-reaction rate of company V to enrofloxacin and oxytetracycline were 10.0% and 20.0%. The other 2 companies did not have cross-reaction. The overall accuracy of all samples ranged from 79.2% to 96.9%. Company I had the highest overall accuracy (96.9%) and company V had the lowest accuracy (79.2%). The average test time of 24 samples is between 57 and 82 min, which meet the requirements of rapid detection technology. The rapid detection of diazepam in aquatic products of company I was qualified. The evaluation of company II-V was not qualified. At present, the performance of diazepam rapid detection products in aquatic products sold in Beijing was still a certain gap with the national legal confirmation method, which needed to be further improved. Conclusion This study is expected to provide reference for the purchase and application of grassroots supervision staff, and promote the application of rapid detection technology in the supervision of aquatic product quality and safety.

Objective To establish a quantitative detection method for the quantitative determination of the viable bacteria number of Bifidobacterium animalis subsp. lactis BB-12 and Lactiplantibacillus plantarum ST-III in fermented milk, by combining propidium monoazide (PMA) with real-time fluorescence quantitative polymerase chain reaction (qPCR). Methods Firstly, the specific primer probe of Bifidobacterium animalis subsp. lactis BB-12 and Lactiplantibacillus plantarum ST-III was designed and verified, the standard curve was established using standard strains, and the reaction conditions of the PMA were optimized. Secondly, the quantities of Bifidobacterium animalis subsp. lactis BB-12 and Lactiplantibacillus plantarum ST-III in the fermented milk samples were quantitatively detected. Results The optimal mass concentration of damaged bacteria of Bifidobacterium animalis subsp. lactis BB-12 and Lactiplantibacillus plantarum ST-III was 10 μg/mL, and the optimal exposure time was 10 min. The PMA-qPCR detection method could accurately detect Bifidobacterium animalis subsp. lactis BB-12 and Lactiplantibacillus plantarum ST-III in fermented milk. Conclusion In this study, a rapid and accurate PMA-qPCR detection method is established for the detection of Bifidobacterium animalis subsp. lactis BB-12 and Lactiplantibacillus plantarum ST-III in fermented milk system, which provides certain reference significance for the quantitative detection of probiotics in fermented milk products.

Objective To elucidate the effects of different cooling rates after purification on the volatile flavor compounds of anhydrous live Crassostrea gigas. Methods This study employed gas chromatography-ion mobility spectrometry (GC-IMS) to analyze the volatile flavor compounds of oysters that were purified for 24 hours and then cooled to 4 °C at varying rates (1, 3, 7, 11 and 16 °C/h). Results The results indicated that 45 kinds of known compounds were detected via GC-IMS, with 5 kinds of compounds identified in their dimeric forms. These compounds included 10 kinds of alcohols, 8 kinds of aldehydes, 6 kinds of esters, 7 kinds of ketones, 4 kinds of hydrocarbons, 3 kinds of furans, 3 kinds of alkenes, and 4 kinds of other compounds. Propanal and isovaleraldehyde levels decreased with increasing cooling rates, while acetone levels increased significantly. A total of 25 kinds of differential flavor compounds, including propionaldehyde, n-butanal, 2-butanone and acetone, were selected based on variable importance in the projection, and these compounds might serve as potential biomarkers for distinguishing oysters during the distribution process. Conclusion This study demonstrates that different cooling rates after purification have a significant impact on Crassostrea gigas in anhydrous preservation, providing theoretical support for the preservation and freshness maintenance of Crassostrea gigas.

Objective To develop a rapid method for the determination of nitrofuran metabolites in aquatic products based on chitosan purification combined with ultra performance liquid chromatography and triple quadrupole/composite linear ion trap mass spectrometer. Methods The samples were hydrolyzed by hydrochloric acid, derived by 2-nitrobenzaldehyde, extracted by ethyl acetate, rapidly purified by chitosan, and then concentrated and redissolved. Rapid separation was achieved by ultra performance liquid chromatography, measured by triple quadrupole/composite linear ion trap mass spectrometer, and quantified by internal standard method to achieve the rapid and accurate determination of nitrofuran metabolites residues in aquatic products. Results The 4 kinds of nitrofuran metabolites had a good linear relationship in the concentration range of 0.5-10.0 μg/L, the correlation coefficients were all more than 0.998, and the limit of quantification was 0.5 μg/kg. Taking carp, Scophthalmus maximus and Litopenaeus vannamei as samples, the average recovery of 4 kinds of nitrofuran metabolites at 3 different addition levels was 96.5%-116.5%, the intra-day relative standard deviation was 2.2%-9.3%, and the intra-day relative standard deviation was 2.7%-9.7%. Conclusion The method is economical, simple, efficient, sensitive and reproducible, and can be used as a routine method for the determination of 4 kinds of nitrofuran metabolites in aquatic products.

Objective To investigate the pollution status of perfluorinated compounds (PFCs) in commercial fish in Liaoning coastal areas. Methods The 6 species of marine commercial fish were collected from 4 coastal areas in Liaoning, including Lvshun, Zhuanghe, Yingkou, and Jinzhou. A standardized pre-processing procedure for marine fish samples was established. PFCs were detected using liquid chromatography-tandem mass spectrometry. The pollution levels of PFCs in the commercial fish were assessed, and the bioaccumulation risk analysis was conducted. Results The main PFCs pollutants in economic fish species in sea were perfluorooctanoic acid (PFOA) and perfluorooctane sulfonates (PFOS). PFOA was detected in all fish samples, with maximum and minimum concentrations of 30.30 ng/g ww and 4.02 ng/g ww, respectively. PFOS was detected in 100% of fish viscera samples but was not found in muscle tissues. Among the tested species, Sebastodes fuscescens, Hexagrammos otakii, and Larimichthys polyactis were more prone to accumulating PFOS and PFOA, indicating potential bioaccumulation effects. Conclusion PFCs contamination is widespread in commercial fish. Continuous monitoring of PFCs shall be implemented, and control measures shall be taken in areas with severe PFOS and PFOA pollution. Ongoing monitoring and risk analysis of these pollutants are essential.

Objective To establish a new method for the determination of 4 kinds of non-volatile N-nitrosamines (NVNA), N-nitrosoproline (NPRO), N-nitrososarcosine (NSAR), N-nitroso-thiazolidine-4-carboxylic acid (NTCA) and N-nitroso-thiazolidine-4-carboxylic acid (NMTCA), in dried smoked fish products by liquid chromatography-tandem mass spectrometry. Methods The samples were extracted by acetonitrile, degreased with n-hexane, separated on a MORHCHEM Caprisil C₁₈-AQ (4.6 mm×250 mm, 5 μm)column, and detected by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in multiple reaction monitoring (MRM) mode, and quantified by the external standard method of matrix standard curve. Results The linearity of the 4 kinds of NVNA was good in ranges of 1,4,10 or 50-800 ng/mL with r²>0.996, the detection limits were 1.36-56.17 μg/kg, the quantification limits were 4.52-187.2 μg/kg, and the spiked recoveries of 4 kinds of NVNA ranged from 90.34%-103.60% with the relative standard deviations (RSDs) of 1.75%-6.47%. Practical applications showed that NVNAs were detected in commercially available samples of the dried smoked fish at different levels and in different species, with the weakly carcinogenic NSAR being detected at higher rates and levels. Conclusion This method is simple in sample pretreatment, good in accuracy and high in precision, which can meet the simultaneous determination of 4 kinds of NVNA in dried smoked fish, and provides a valuable technical reference for the regulation and control of the NVNA contamination level in dried smoked fish products.