To establish a method for determination of single-copy nuclear gene targets of animal-derived components in food by real-time fluorescence quantitative polymerase chain reaction (qPCR).

qPCR primers and Taqman probes were designed to target the specific nuclear genes of common animal-derived components in food to verify and confirm the specificity and sensitivity of the method. The applicability and stability of simulated and actual commercially available animal-derived food detection methods were adopted, and the qPCR detection values were compared and analyzed with those of mitochondrial cytoplasmic gene target detection.

The qPCR primer probe for single-copy nuclear gene targets had good specificity, with a minimum limit of detection of 0.1 ng/μL DNA mass concentration, nuclear genes could accurately identify the minimum adulteration component content of 0.1% (mass ratio). The cycle threshold (Ct) value of the nuclear genes amplification reactions were all greater than that of the cytoplasmic target gene, and the amplification reactions of cytoplasmic genes could recognize a lower adulteration content of 0.01% (mass ratio). In the testing of simulated and actual commercially available samples, the nuclear gene qPCR reaction could accurately and effectively detect animal-derived samples mixed with different source components, and it was not easy to detect chicken essence ingredients and other source contamination components from the production line.

The research results of this paper show that the qPCR amplification system established based on single-copy nuclear gene targets has strong specificity and high sensitivity for the detection of common animal-derived components in food. Compared with the amplification results of mitochondria genes, the nuclear genes’ detection method is less affected by the substitution of ingredients and the cross-contamination on the production line, and can quickly and accurately detect animal-derived component in food, which make it conducive to market supervision and risk assessment.

To investigate the aluminum residue levels in flour products sold in a certain province in Northwest China and assess population dietary exposure risks.

A total of 333 fried flour products, baked goods and Liangpi sold in a certain province in Northwest China from 2023 to 2024 were collected. The products were tested using the inductively coupled plasma mass spectrometry method specified in GB 5009.268—2016 National food safety standard-Determination of multi-elements in foods, with contamination indices analyzed to evaluate aluminum residues. Dietary exposure risks were assessed using point evaluation methods based on adult consumption patterns.

Among 333 batches of wheat flour product samples, the overall detection rate of aluminum was 85.3%, the exceedance rate was 0%, and the average residual concentration was 5.71 mg/kg. For the 3 kinds of commercially available wheat flour products, the single-factor pollution index of aluminum was all less than 1, and the comprehensive pollution index was all less than 0.7, indicating a clean pollution level and a safe pollution grade. The average dietary aluminum exposure of adult residents in this province through the 4 kinds of commercially available wheat flour products was 0.019 mg/(kg·BW), which accounted for 0.97% of the provisional tolerated weekly intake (PTWI) of aluminum. For the high-exposure population, the average dietary aluminum exposure through the 4 kinds of commercially available wheat flour products was 0.046 mg/(kg·BW), accounting for 2.32% of the PTWI. Among the 4 kinds of wheat flour products, fried wheat flour products contributed the most to dietary aluminum exposure. For adult residents of different genders and age groups (18–44 years old, 45–60 years old, and over 60 years old) in this province, both the mean value and the 95th percentile (P₉₅) value of daily dietary aluminum exposure from wheat flour products did not exceed the PTWI, which indicated a low risk of dietary aluminum exposure from commercially available wheat flour products in this province.

In a province in Northwest China, various types of commercially available wheat flour products exhibit generally mild aluminum pollution and relatively high safety from 2023 to 2024. Consistent with the low aluminum residual levels detected, the average dietary exposure and high-exposure dietary risks of aluminum for adult residents across different genders and age groups remain within acceptable ranges. However, continuous attention and monitoring of food safety risks in wheat flour products are still necessary, and targeted measures should be implemented to further prevent and reduce the risk of dietary aluminum exposure from these products.

To develop a dual recombinase polymerase amplification (RPA)-mediated colloidal gold strip assay for the rapid and visible simultaneous detection of 2 kinds of marker genes, the neomycin phosphotransferase II gene (NPT II) and the hygromycin phosphotransferase II gene (HPT II), in transgenic plants.

In this study, highly specific gene fragments of NPT II and HPT II were selected to design corresponding amplification primers. Using RPA technology, the 2 kinds of target nucleic acids were rapidly and stably amplified exponentially. The amplification products were subsequently detected by a dual test strip for rapid visual interpretation. On the test strip, the corresponding detection lines (test line N, test line, T_N and T_H lines) and the quality control line (C line) developed visible signals, allowing qualitative analysis based on the color intensity of the T_N, T_H, and C lines.

The assay was performed under isothermal conditions at 40 °C, involving a 15 min dual RPA reaction followed by a 5 min antigen‑antibody recognition step on the test strip. It achieved precise detection with limits of detection of 615 copies/µL for the NPT II gene and 314 copies/µL for the HPT II gene, and enabled rapid screening in simulated reald samples down to 0.10% for NPT II and 0.05% for HPT II.

The dual RPA-mediated colloidal gold strip method developed in this study enables visual detection of the marker genes NPT II and HPT II. Characterized by user-friendly operation, rapid detection and high specificity, this platform demonstrates significant potential for broad application in point-of-care testing.

To establish an immunochromatographic technique that can provide both visual and fluorescent signal readout at the same time. To evaluate the practical application performance of this technology for high-sensitivity and high-accuracy detection of trace tadalafil in complex matrices of energy drinks.

In this study, magnetic nanoparticles were first combined with quantum dots to prepare magnetic quantum dot composite materials, which were then used to label the anti-tadalafil antibody, thereby constructing a highly sensitive and specific magnetic quantum dot probe. Meanwhile, a pre-incubation step was introduced to effectively eliminate matrix interference. During the experimental process, key conditions including the antibody labeling amount, type of blocking agent, resuspension buffer system and composition of the incubation solution were systematically optimized.

Experimental data showed that the dual-modal immunochromatographic technology achieved a visual limit of detection for tadalafil of 0.5 ng/mL in the colorimetric mode and 1 ng/mL in the fluorescent mode.Additionally, the technology exhibited excellent specificity with no cross-reactivity observed with structural analogs such as sildenafil and vardenafil.

The dual-mode immunochromatographic technique based onmagnetic quantum dots ingeniously combine the high purification capability of magnetic separation technology with the high fluorescence sensitivity of quantum dots, offering significant advantages such as simplicity of operation and strong anti-interference ability. This technique can achieve rapid screening and preliminary quantification of tadalafil in functional foods on-site, providing a practical and efficient technical solution for the detection of illegal additives in functional foods.

To establish a method for the determination of nitroimidazole drugs residues in egg, chicken and pork matrices by high performance liquid chromatography-tandem mass spectrometry.

Samples were ultrasonically extracted with acetonitrile and acetonitrile-water solution, followed by degreasing with N-hexane saturated with acetonitrile. After centrifugation, the lower extract was purified using a Prime HLB solid-phase extraction column to instrumental analysis. Separation was achieved on a C₁₈ column (2.1 mm×100 mm, 1.8 μm) with a gradient elution using 0.1% formic acid in water and acetonitrile as mobile phases. Quantification was performed by the external standard method.

The 10 kinds of nitroimidazole drugs exhibited good linearity within the range of 1–100 ng/mL, with correlation coefficients (r²) exceeding 0.995. The limit of quantitation for all compounds was 1.0 μg/kg. Average spike recoveries at 3 levels (1, 2 and 10 time limit of quantitation) ranged from 80.1% to 107.7%, with relative standard deviations between 0.8% and 7.5%. Analysis of 150 batches of samples using this method detected 3 positive batches: Metronidazole was identified in 2 egg samples (896.0 μg/kg and 1341.3 μg/kg), and dimetridazole was found in 1 chicken sample (480.2 μg/kg).

This method is highly efficient and accurate, capable of conducting qualitative and quantitative analysis of nitroimidazole drugs in pork, chicken and egg products. It effectively addresses the issues of incomplete food matrix and cumbersome operation in the current national standards, and provides technical support for ensuring the hygiene and safety of animal-derived foods.

To investigate the biogenic amine contamination status of commercial fermented alcoholic beverages in Sichuan Province.

The 9 kinds of biogenic amines in 90 fermented alcoholic beverage samples from 5 surveillance sites in Sichuan Province were determined by solid-phase extraction-high performance liquid chromatography. The detection results were analyzed, and a dietary exposure risk assessment for histamine and tyramine frequently detected from wine and Huangjiu was conducted by point estimation method based on the hazard quotient (HQ).

The detection rate of biogenic amines was 87.8%; putrescine, octopamine, tyramine and histamine were relatively frequently occurring biogenic amines, detected from 87.8%, 75.5%, 63.3% and 48.9% of the samples, respectively. In Huangjiu, wine and beer, the average total content of biogenic amines were 75.25, 16.61 and 10.31 mg/L, respectively. The HQ of histamine and tyramine in Huangjiu and wine was less than 1 for the healthy population, while the HQ of tyramine in Huangjiu was greater than 1 for classic monoamine oxidase inhibitor (MAOI) users.

Commercial fermented alcoholic beverages in Sichuan Province are commonly contaminated with biogenic amines. The total content of biogenic amines is the highest in Huangjiu, followed by those in wine and beer. The dietary exposure risk of biogenic amines in fermented alcoholic beverages is acceptable for the healthy population, while the dietary exposure risk posed by tyramine in Huangjiu to classic MAOI users requires attention. Measures including material and strain optimization and process improvement can be taken to further reduce biogenic amine contamination in fermented alcoholic beverages.

To explore the feasibility of constructing a rapid and nondestructive detection model for fumonisin (FUMs) in corn residue using hyperspectral imaging (HSI, spectral range 900–1700 nm) combined with deep learning methods.

Corn bran samples containing a concentration gradient of FUMs (0–6 mg/kg)were artificially prepared (total of 175 samples). After removing interference through multiplicative scatter correction(MSC) preprocessing, the univariate variable elimination (UVE) and variable combination population analysis (VCPA)methods were used to identify key feature wavelengths for FUMs (26 wavelengths), respectively.

After comparing models including partial least squares regression (PLSR), support vector machine (SVM), convolutional neural network (CNN), long short-term memory (LSTM), gated recurrent unit (GRU) and Attention, the CNN-GRU-Attention fusion model demonstrated optimal performance: For FUMs detection, the prediction coefficient of determination reached 0.9328, the root mean square prediction error was 0.3931, and the prediction deviation ratio was 3.8247.

The established detection method enables rapid, precise and nondestructive simultaneous detection of FUMs, providing a novel technical pathway for grain mycotoxin detection and offering reference for the application of interpretable deep learning in spectral analysis.

To establish a method for the simultaneous determination of 46 kinds of antibiotic residues including 22 kinds of sulfonamides, 15 kinds of quinolones, 9 kinds of nitroimidazoles in animal muscle tissues by ultra performance liquid chromatography-tandem mass spectrometry.

The samples were extracted by 90% acetonitrile aqueous solution, purified by PRiME HLB solid-phase extraction column, concentrated by nitrogen blowing and converted to solvent, and determined by ultra performance liquid chromatography-tandem mass spectrometry. The mobile phase consisted of 0.1% formic acid in water and acetonitrile, with gradient elution.Detection was performed in multiple reaction monitoring mode, and quantification was carried out using the external standard method.

The 46 kinds of antibiotics showed good linear relations within their respective concentration ranges, with limits of quantitation ranging from 1-5 μg/kg. The average recovery rates were 60.2% to 106.8%, and the relative standard deviations were 0.2% to 12.2%.

This method features high detection efficiency and high throughput, and can meet the rapid screening requirements of sulfonamides, quinolones and nitroimidazoles in animal muscle tissues.

To establish a method for the detection of residues of 6 kinds of pesticides such as pyrazolimide and benzophenone in vegetables by QuEChERS-gas chromatography-tandem mass spectrometry(GC-MS/MS).

Adopted the improved QuEChERS-GC-MS/MS for detection. The samples were extracted with acetonitrile, separated by SH-1-5SILMS capillary chromatographic column (30 m×0.25 mm, 0.25 µm), and the multiple reaction monitoring (MRM) scanning mode was used to monitor the target ions of pesticides.

The linear relationship of the 6 kinds of pesticides was good within the range of 0.002–0.200 mg/L, and the correlation coefficient (r²) was all greater than 0.998. The limits of detection were 0.33–1.23 µg/kg, the limits of quantitation were 1.10–4.09 µg/kg, and the average recovery rates were 93.66%–111.29%. The relative standard deviation ranged from 2.79% to 11.27%.

This method enables qualitative and quantitative analysis of 6 kinds of pesticide residues, including pyrazoleanilide and benomyl, in vegetables. Characterized by good repeatability, low cost, and efficient convenience, it provides a methodological reference for routine testing of such residues in China. It offers robust technical support for advancing pesticide residue detection techniques and enhancing safety oversight within relevant industries.

To investigate the pollution situation of aflatoxin B₁ in commercially available edible vegetable oils in a certain province in Northwest China and evaluate the dietary exposure risk for local residents.

A total of 233 commercially available edible vegetable oil samples were collected from the northwest province between 2023 and 2024. Aflatoxin B₁ content was determined in accordance with GB 5009.22—2016 National food safety standard-Determination of aflatoxins B and G in foods. The aflatoxin B₁ content in edible vegetable oils was analyzed, and the point assessment method was applied to assess the dietary exposure risk of aflatoxin B₁ among the general population based on adult dietary consumption data.

Among the 233 batches of edible vegetable oil samples, the overall detection rate of aflatoxin B₁ was 0.43%, with no samples exceeding the standard limit. The average aflatoxin B₁ content was 0.017 μg/kg. The average dietary exposure and high exposure level (95th percentile, P₉₅) of aflatoxin B₁ from edible vegetable oils for adult residents in this province were 0.011 ng/(kg·BW·d) and 0.009 ng/(kg·BW·d), respectively. Both the mean and P₉₅ values of the margin of exposure (MOE) were greater than 10000, suggesting that the liver cancer risk associated with aflatoxin B₁ exposure was within the acceptable range for adult residents.

The pollution situation of aflatoxin B₁ in various commercially available edible vegetable oils in a certain province in Northwest China during 2023—2024 is generally mild, with a high level of safety. The average dietary exposure, high-exposure dietary risk and liver cancer incidence risk of adult residents of different genders in all age groups are all within the acceptable range. However, it is still necessary to continuously pay attention to and monitor the food safety risks of edible vegetable oils, strengthen supervision and further prevent and reduce the dietary exposure risk of aflatoxin B₁ in edible vegetable oils.