Objective To analyze the differences in mineral elements in wild rice from different regions and establish a method for tracing the origin of wild rice based on mineral element fingerprint characteristics. Methods Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze the content of 24 kinds of mineral elements in 40 wild rice samples from the United States, Canada, and China. The data were subjected to variance analysis, multiple analysis, principal component analysis, and discriminant analysis to explore the feasibility of using mineral element fingerprint characteristics for tracing the origin of wild rice. Results The content of 24 kinds of elements showed significant differences among the regions. Principal component analysis extracted 3 principal components, with a cumulative variance contribution rate of 93.1%. Principal component analysis successfully distinguished wild rice from the United States and Canada. Discriminant analysis correctly identified 97.7% of the wild rice samples. Conclusion This study demonstrates the feasibility and accuracy of classifying wild rice samples from different origins.

Objective To establish a chronoamperometry detection method for accurately determining the nitrite content in food. Methods Cobalt nanoparticles, graphene oxide, and polypyrrole were electrodeposited on the electrode surface to construct an electrochemical sensor for nitrite detecting. The detection conditions were optimized, and the linear range of chronocurrent method for nitrite detection was determined. After the specificity of the detection method was verified, the samples were tested using the optimized detection conditions. Results An electrochemical sensor for nitrite detection was prepared. The optimal potential for this method was 0.85 V, the optimal pH was 8.0, and the optimal deposition time was 300 s. The interfering substances dopamine, ascorbic acid and uric acid had little impact on the detection of nitrite, and the detection of samples found that the established method had high accuracy. Conclusion An electrochemical sensor for detecting nitrite is prepared, which has good stability and high accuracy, and is suitable for the determination of nitrite content food.

Objective To optimize a compound desulfurizer of pickled pepper raw material by principal component analysis and response surface method. Methods The limit of detection was based on GB 2760—2014 National standard for food safety-Standards for the use of food additives, selected 3 kinds of desulfurizers with good desulfurization effect and little influences on raw material quality from 9 kinds of common desulfurizers by single factor experiments, designed a 3-factor, 3-level experiment by response surface method, through principal component analysis and response surface analysis, the optimum compound ratio and the optimum operating conditions were obtained. Results When the mass fraction of calcium hydroxide was 44.05%, sodium bicarbonate was 35.57%, chlorine dioxide was 20.38%, and the concentration was 0.10%, the desulfurization rate could reach 94.55%, which was about 36.50% higher than that of no use. At the same time, the color and hardness of pickled pepper materials had no obvious changes. Conclusion The study obtains a kind of compound desulfurizer with good desulfurization effect and little influences on raw material quality, and has high application value.

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.

As the cornerstone of the global food system, wheat flour, a derivative product of limited wheat in various countries, is not only an important component of human daily diet, but also a key element in maintaining global food security. However, in recent years, the frequent contamination of fungal toxins in wheat flour has become a major challenge in the field of food safety, posing a significant threat to food safety and human health. The main types of fungal toxins in wheat flour include deoxynivalenol, aflatoxin, zearalenone, etc. The contamination of deoxynivalenol is the most prominent, but there are certain differences in the relevant limit standards at home and abroad. This study aimed to comprehensively review the types and contamination status of major fungal toxins in wheat flour. By comparing relevant limit standards at home and abroad, it could be found that different countries and regions had different assessment and management strategies for food safety risks. Based on the analysis and discussion of the above content, a comprehensive prevention and control strategy is proposed, aiming to provide scientific guidance and technical support for the safe production, processing, and consumption of wheat flour.

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 study the distribution characteristics and health risk exposure levels of 6 kinds of common quinolone antibiotics in poultry eggs and chicken meat in Inner Mongolia. Methods The content of norfloxacin, enrofloxacin, ofloxacin, pefloxacin, ciprofloxacin and lomefloxacin in poultry eggs and chicken samples randomly collected from some cities in the region. In 2021, 2022 and 2024 were determined by isotope internal standard, solid phase extraction, ultra performance liquid chromatography-tandem mass spectrometry, the data of quinolone residues in poultry eggs and chicken in the whole region were statistically analyzed, according to the reference value of different age groups dietary intake and detected data, the hazard quotient of each age group was calculated and the health risk to the population was analyzed. Results In 2021, the detection rate of poultry eggs was 5.00% (3/60), the exposure levels was 0.09-0.52 μg/(kg·d), and the hazard quotient was 0.004-0.021; the detection rate of chicken was 16.70% (10/60), the exposure levels was 0.23-12.39 μg/(kg·d), and the hazard quotient was 0.009-0.492. In 2022, the detection rate of poultry eggs was 6.25% (5/80), the exposure levels was 0.09-0.49 μg/(kg·d), and the hazard quotient was 0.004-0.019; the detection rate of of chicken was 3.75% (3/80), the exposure levels was 0.01-0.68 μg/(kg·d), and the hazard quotient was 0.0004-0.0270. In 2024, the detection rate of poultry eggs was 3.33% (4/120), the exposure levels was 0.13-0.70 μg/(kg·d), and the hazard quotient was 0.005-0.028; the detection rate of chicken was 6.36% (7/110), the exposure levels was 0.03-1.58 μg/(kg·d), and the hazard quotient was 0.001-0.063. Conclusion The 3 years of analysis data shows that quinolone antibiotics are detected in poultry eggs or chicken almost all cities, the average detected in chicken is higher than that in poultry eggs. The exposure risk of quinolone antibiotics in poultry eggs and chicken in 4 age groups is less than 1 and the health risk is small.

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 understand the prevalence, serotype distribution and drug resistance of Salmonella from foodborne diseases in Fengtai District, Beijing from 2016 to 2023. Methods Salmonella was isolated and identified from the stool samples of foodborne diseases. Serotypes of Salmonella were identified by slide agglutination test. The antimicrobial resistance of Salmonella was determined by micro broth dilution method and minimum inhibitory concentration method. Results The detection rate of Salmonella was 4.33%, which increased from 2.11% to 9.28% from 2016 to 2023. Salmonella infection peaked in autumn. The detection rate of Salmonella was higher in people aged 0-9 old years and 40-49 old years, and people of fever, nausea and diarrhea more than 6. The consumption of meat and meat products was the risk factor of Salmonella infection. The top 5 serotypes were Salmonella enteritidis, Salmonella typhimurium, Salmonella thompson, Monophasic salmonella enterica serovar typhimurium and Salmonella senftenberg. There was an upward trend in the detection rate of Salmonella thompson, and Monophasic salmonella enterica serovar typhimurium. The resistance rate of Salmonella to nalidixic acid (NAL), ampicillin (AMP) and ampicillin-sulbactam (AMS) was higher, the intermediate rate of Salmonella to ciprofloxacin (CIP) was higher, and the sensitivity of Salmonella to gentamicin (GEN), imipenem (IMI) and azithromycin (AZI) was higher. The drug resistance of Salmonella enteritidis was the most serious, the drug resistance rate of tetracycline (TET) and ceftazidime (CAZ) was increasing, and the intermediate rate of CIP was decreasing. The multi-drug resistance rate of Salmonella was 44.00%, which included 31 drug resistance profiles. Conclusion The detection rates of Salmonella are different in different age, different symptoms and food exposure history of people, and different season. Salmonella enteritidis is the main serotype. The serum distribution of Salmonella is dispersive. The resistances of Salmonella to quinolones antibiotics and β-lactam antibiotics are serious, and the situation of multi-drug resistance is serious. We should enhance food safety education on Salmonella, strengthen surveillance on meat food safety, strengthen surveillance on new salmonella species such as Monophasic salmonella enterica serovar typhimurium, strengthen the use of antibiotics, and optimize measures for disease prevention and control of Salmonella.

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.