To establish a method for simultaneous detection of 38 kinds of veterinary drug residues(including tetracyclines, sulfonamides, quinolones, β-agonists, amantadine, chloramphenicol, thiamphenicol, etc.) in raw pork puree for infant complementary foods by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).

Samples were extracted with acetonitrile and ethylenediaminetetraacetic acid disodium salt (Na₂EDTA)–Mcllvaine buffer, cleaned-up on an Oasis PRiME HLB cartridge, concentrated to dryness under nitrogen at 40 °C and reconstituted in 0.2% formic acid. Chromatographic separation was performed on a Phenomenex Kinetex® 2.6 µm EVO C₁₈ column, and the analysis was conducted using multiple reaction monitoring with dynamic polarity switching via an Agilent Jet Stream electrospray ionization source (AJS ESI), with quantification based on a matrix-matched calibration standard approach.

The 10 kinds of target compounds and 28 kinds of target compounds showed good linear responses in the concentration ranges of 10–400 µg/L and 10–500 µg/L, respectively, and the correlation coefficients (r) of the obtained calibration curves were all no less than 0.995. The limits of detection were determined to range from 0.03 to 1.47 µg/kg, with the limits of quantitation established between 0.10 and 4.90 µg/kg. At 3 spiked levels of 5, 10 and 20 µg/kg (n=6), the average recoveries ranged from 64.32% to 111.66% with relative standard deviations of 2.17%–10.70%, meeting the requirements specified in GB/T 27404—2008 Specifications for quality control in laboratories-Physical and chemical testing of food.

This method offers straightforward operation, high sensitivity, good accuracy and precision,enabling high-throughput screening and confirmation of 38 kinds of veterinary drug residues in pork puree used as raw material for infant complementary foods.

To optimize the composition of the culture medium for Pediococcus acidilactici TC-4 and the formula of freeze-drying protectants.

The composition and mass concentration of the culture medium for Pediococcus acidilactici TC-4 and the formula of the freeze-drying protectant were screened by combining single-factor experiments, Plackett-Burman experiments and response surface methodology.

The optimal composition of the culture medium was: Glucose 26 g/L, yeast extract 30 g/L, sodium acetate 8 g/L, diammonium hydrogen citrate 2 g/L, dipotassium phosphate 2 g/L, magnesium sulfate 0.4 g/L, manganese sulfate 0.075 g/L and Tween 80 1 g/L. The viable count increased from 3.50×10⁹ CFU/mL to 1.09×10¹⁰ CFU/mL, which was 3.11 times that before optimization. The optimal formula of the freeze-drying protectant was: Sodium L-glutamate 8%, maltitol 14%,skim milk powder 18%, and the survival rate reached 90.77%.

The optimization of the culture medium for Pediococcus acidilactici TC-4 is completed, and a high-viable probiotic preparation is successfully prepared, lays a solid theoretical foundation for the industrialization of this strain.

To establish a method for the rapid identification of duck-derived components in mutton by duplex real-time fluorescence polymerase chain reaction (dRT-PCR).

First, the response surface methodology was used to optimize various conditions for the rapid extraction of DNA from animal tissues.Subsequently, multiple sets of specific primers were designed based on the differences between the sheep mitochondrial cytochrome b gene (CYTB) and the duck cytochrome c oxidase subunit III (COX3). The dRT-PCR experiment was conducted using the rapidly extracted animal tissue DNA. By analyzing the melting curve, the sheep and duck-derived components were qualitatively identified according to the differences in peak temperature.

The optimized method for crude extraction of animal tissue DNA could extract 586 ng/μL of DNA suitable for species detection from 20 mg of animal tissue within 5 minutes. The sheep-derived gene products and duck-derived gene products produce melting peaks at 84.79 ℃ and 81.66 ℃ respectively, with no specific amplification for non-target species. It could quickly detect more than 0.01 ng/μL of crude duck DNA within 1 hour.

This method is simple to operate, low in cost, and has high sensitivity, providing effective technical support for the identification of adulteration in mutton products.

To understand the distribution and prevalence characteristics, virulence gene carriage,drug resistance trends and multi-drug resistance situation of Bacillus cereus in Ningxia Region.

This study conducted biochemical and mass spectrometry re-identification, multiple fluorescence quantitative polymerase chain reaction for virulence genes and microbroth dilution method for drug sensitivity tests on 312 isolates of Bacillus cereus obtained from monitoring points from 2010 to 2025, and analyzed the results.

A total of 312 strains of Bacillus cereus were detected from 2010 to 2025, including 284 strains from food samples and 28 strains from food poisoning. Among them, 78 strains were isolated in the early period, 112 in the middle period, and 122 in the late period. There were regional differences among the 5 cities of Yinchuan, Shizuishan, Wuzhong, Guyuan and Zhongwei. Yinchuan had the highest rate, followed by Wuzhong City, and the lowest was Shizuishan City. The carriage rate of virulence genes in Bacillus cereus exceeded 97%. The dominant genotype was double positive for gene nheB and gene hblC accounted for 52.82%. The resistance rates to ampicillin (AMP), penicillin (PEN), cefoxitin(CFX) and oxacillin (OXA) all exceeded 90%. The strains were 100% sensitive to ciprofloxacin (CIP),chloramphenicol (CHL), gentamicin (GEN), vancomycin (VAN) and imipenem (IMP). The most common resistance pattern was AMP-PEN-OXA-CFX, accounting for 60.90%.

The number of Bacillus cereus detected in Ningxia has been steadily increasing. It showes diversity in terms of time, source and region. The carriage rate of virulence genes is high, and the drug resistance situationwas is severe. Continuous monitoring of food and patients should be carried out, and effective measures should be taken for control to better ensure food safety and public health.

To establish a technical method based on untargeted metabolomics, analyze the differences in metabolites after blending glacial acetic acid (ethanol fermentation method) in brewed vinegar, and screen characteristic markers for adulteration identification.

Taking Ninghuafu traditional aged vinegar as the research object, ultra performance liquid chromatography-quadrupole-Orbitrap tandem mass spectrometry(UPLC-Q-Orbitrap MS/MS) was used to collect metabolite components of vinegar samples with different dilution degrees (acidity ranging from 6.0%–8.0%). Combined with multivariate statistical analysis methods such as principal component analysis and partial least squares discriminant analysis, differential metabolites were screened and identified.

A total of 5 markers with significantly differences were identified, including oleamide,N-benzyl-linoleamide, triethylcitrate, dibutyladipate and monopalmitin. When the content of oleamide was significantly lower than 479.99 µg/kg, and the content of N-benzyl-linoleamide, triethylcitrate, dibutyladipate and monopalmitin were higher than the levels in traditional brewed vinegar (0.92, 0.89, 10.82 µg/kg and 56.56 mg/kg,respectively), these compounds could effectively distinguish whether the vinegar had been adulterated. The content of oleamide showed a significant downward trend with increasing glacial acetic acid concentration, with a content of 39.40 µg/kg in samples with an acidity of 8.0%. N-benzyl-linoleamide (9.50 µg/kg) reached peaks in the sample groups 7.0% acidity. Triethylcitrate (4.22 µg/kg), monopalmitin (129.26 mg/kg) and dibutyladipate (27.66 µg/kg) in the 8.0% acidity sample reached 4.75, 2.29 and 2.56 times that of traditional vinegar.

The untargeted metabolomics method based on UPLC-Q-Orbitrap MS/MS established in this study screens out significantly differential biomarkers, which provides a novel technical approach for the authenticity identification of vinegar, and guarantees the quality of vinegar products as well as protects the health rights and interests of consumers.

To investigate the aluminum contamination level and its sources in Amorphophallus konjac K. Koch products in Southern Shaanxi in 2022—2025, and assess the dietary exposure risk of aluminum from these products.

A total of 109 Amorphophallus konjac K. Koch products were systematically collected from Southern Shaanxi. The aluminum content was determined according to GB 5009.182—2017 National food safety standard-Determination of aluminum in foods. The average daily consumption was estimated under 2 kinds of extreme assumptions, namely the tuber consumption estimation method and the dietary fiber recommended intake back-calculation method. Combined with the aluminum content data, the chronic hazard quotient (cHQ) was calculated using the point assessment approach to evaluate the dietary exposure risk of aluminum.

The detection rate of aluminum in 109 samples was 78.0%, with a median content of 28.8 mg/kg. Among the 29 samples with aluminum content exceeding 100 mg/kg, bulk products accounted for 65.5% and non-ready-to-eat products accounted for 86.2%. Under the general consumption level estimated by the tuber consumption estimation method,the cHQ values of all samples were less than 1, indicating acceptable risk. Only when the theoretical consumption(0.0982 kg/d, based on the average recommended intake) calculated by the dietary fiber recommended intake back-calculation method was combined with the 90th percentile (P90) aluminum content (261 mg/kg), the cHQ value was greater than 1, suggesting a theoretical potential risk.

The overall aluminum content in Amorphophallus konjac K. Koch products in Southern Shaanxi is relatively low, and conventional consumption by the general population is safe. However, localized contamination is prominent, and bulk non-ready-to-eat products are high-risk categories for aluminum contamination. It is recommended that small workshops and farmers’ markets be taken as key supervision targets to further reduce the dietary aluminum exposure risk of residents.

To establish a method for the determination of glucosamine hydrochloride content in health foods, with phenyl-isothiocyanate as the derivatizing reagent by pre-column derivatization-high performance liquid chromatography (HPLC).

Samples were ultrasonically extracted with water, and the extract was derivatized with phenyl-isothiocyanate. Separation was achieved on an Agilent Poroshell 120 EC-C₁₈ column (4.6 mm×150 mm, 4 μm) via gradient elution with sodium acetate and methanol as mobile phases at a flow rate of 0.8 mL/min.Detection was performed at 245 nm using a HPLC-ultraviolet detector. Pre-column derivatization conditions: 1 mL sample solution was vortex-mixed with 6 mL phosphate buffer, equilibrated at room temperature for 15 min, then mixed with 2 mL phenyl-isothiocyanate reagent in the same colorimetric tube. The mixture was heated in an 80 ℃water bath for 30 min, rapidly cooled to room temperature, and diluted to 10 mL with water.

Glucosamine hydrochloride exhibited a good linearity in the range of 25–250 mg/100 g (r²=0.9993). The limit of detection for glucosamine hydrochloride was 0.0050 mg/mL, and the limit of quantitation was 0.0100 mg/mL. The repeatability relative standard deviation was 0.81%, and the recovery rates ranged from 97.9% to 99.9%.

This method is simple to operate and exhibits good repeatability, making it suitable for the determination of glucosamine hydrochloride content in health foods.

To establish n method for simultaneously identifying multiple meat species within a single reaction system by efficient multiplex polymerase chain reaction (PCR) technology.

Based on species-specific variations in animal mitochondrial gene sequences, primers were designed and screened using multiple bioinformatics tools, and an octuple PCR assay was developed for the simultaneous detection of 8 kinds of meat species, namely mutton, chicken, rabbit, pigeon, goose, turkey, ostrich and dog. The specificity of the amplification products was confirmed through reaction condition optimization and DNA sequencing. The sensitivity and applicability of the method were further evaluated by multi-species DNA mixtures and adulterated meat model samples.

The octuple PCR assay enabled stable and simultaneous amplification of DNA from all 8 kinds of target species in a single reaction tube, with no nonspecific amplification observed. Sequencing results were consistent with the corresponding target species. Sensitivity analysis showed that, in both raw and heat-processed meat samples, the limits of detection for the target species ranged from 0.01 to 0.05 ng of genomic DNA. In adulterated samples, target meat components were detectable at levels as low as 0.10%.

The established octuple PCR method can be successfully applied to the authenticity assessment of commercially available meat products, allowing rapid and accurate identification of multiple meat species. This method demonstrates good practical applicability and provides effective technical support for food safety surveillance and market regulation.