To establish a method for rapid determination of the aflatoxin B₁ (AFB₁) and zearalenone(ZEN) in Zea mays L. by molecularly imprinted-surface‑enhanced Raman spectroscopy (SERS).

Dual‑template molecularly imprinted materials were prepared and used for the pretreatment and purification of Zea mays L.. Ag nanoparticles were employed as the SERS‑active substrate, and a label‑free detection method was developed based on the characteristic SERS peaks of AFB₁ and ZEN. The effects of molecularly imprinted materials preparation conditions and SERS detection parameters (including substrate concentration and type of aggregating agent)on the analytical performance were investigated.

Under the optimized conditions, dual‑template molecularly imprinted materials pretreatment (template-to-monomer molar ratio of 1:2), Ag nanoparticles concentration of 0.56 mmol/L, and potassium bromide and magnesium chloride as aggregating agents for AFB₁ and ZEN, respectively. The limits of detection were 1.5 ng/mL for AFB₁ and 5.0 ng/mL for ZEN. The linear ranges for both toxins were 10–1000 ng/mL, with determination coefficients of 0.9268 for AFB₁ and 0.9611 for ZEN. The average recoveries ranged from 93.29% to 96.10%, and the relative standard deviations were all below 5%.

The established method is simple, rapid, accurate, and suitable for on‑site rapid screening of AFB₁ and ZEN in Zea mays L. powder.

To develop a method for the rapid quantitative detection of ochratoxin A in grain, oil crops and nuts by quantum dot fluorescence.

Using polystyrene microsphere quantum dot loading technology, a quantum dot microsphere probe with high fluorescence intensity was constructed by covalent coupling, ochratoxin A monoclonal antibody was coupled to the probe surface by activation coupling method, and the quantum detection system of ochratoxin A was constructed.

Through the optimization of experimental parameters, the established quantum dot fluorescence detection system showed excellent analytical performance for ochratoxin A.The linear relationship was good in the range of 1–20 ng/mL (r²>0.99), and the limits of detection and limits of quantitation were as low as 0.5 ng/mL and 2.0 ng/mL. The method had strong specificity, there was not significant cross reaction with common mycotoxins such as deoxynivalenol and zearalenone. The method was validated by methodology according to the standard of LS/T 6142—2023 Evaluation protocol for rapid detection method of mycotoxins in grains, spiked recovery rates were 90.3%–114.5%, and the relative standard deviation was less than 15%, the method of accuracy and precision met the requirements of the detection specification about ochratoxin A.

The quantum dot fluorescence detection system for ochratoxin A has the advantages of high sensitivity, good specificity, simple operation and rapid analysis, it is suitable for rapid and accurate quantitative detection of ochratoxin A in grain, oil crops and nuts, it provides an effective technical means for the field screening and monitoring of mycotoxins in agricultural products.

To develop an electrochemiluminescence (ECL) test strip for the detection of aflatoxin B₁(AFB₁).

The ECL test strip was fabricated by patterning carbon ink electrode onto the surface of a polyvinyl chloride substrate and then assembling them with a lateral flow immunoassay strip. The electrochemical performance of the ECL test strip was investigated using cyclic voltammetry. Meanwhile, Ru-PEI/Ti₃C₂T_x@Au composites were synthesized and conjugated with AFB₁ monoclonal antibodies (Anti-AFB₁) to serve as ECL signal probes. Through the competitive immunoreaction between the AFB₁-bovine serum albumin conjugate immobilized on the test line of the ECL test strip and the ECL signal probes, colorimetric and ECL signals were obtained.

The fabricated ECL test strips exhibited good stability and specificity. Under optimal conditions, the colorimetric signal showed a good linear relationship with the logarithm of AFB₁ concentration in the range from 0.1 ng/mL to 100.0 ng/mL, with a limit of detection of 32 pg/mL. In addition, the ECL signal showed a good linear relationship with the logarithm of AFB₁ concentration in the range from 1.0 pg/mL to 100.0 ng/mL, with a limit of detection of 319 fg/mL. Furthermore, satisfactory recovery rates ranging from 92.6% to 110.3% were achieved by the proposed ECL test strips, along with relative standard deviations of 0.9% to 6.2%.

The developed ECL test strip enables highly sensitive and rapid detection of AFB₁ in corn samples, providing a new perspective for rapid mycotoxin detection.

To establish an analytical method for the simultaneous determination of 50 kinds of mycotoxins in Dimocarpus longan Lour. and its dried products by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

Samples were ultrasonically extracted with formic acid-acetonitrile-water (1:79:20, V:V:V), and purified with an Oasis PRiME HLB solid-phase extraction column.Chromatographic separation was performed on a Waters CORTECS T3 column (2.1 mm×100 mm, 2.7 μm) with gradient elution using 0.1% formic acid aqueous solution and methanol-acetonitrile (4:6, V:V) as mobile phases.Detection was carried out in positive and negative electrospray ionization modes with multiple reaction monitoring, and quantification was achieved using the matrix-matched external standard method.

Under optimized conditions, the 50 kinds of mycotoxins exhibited good linearity in a certain mass concentration (r²>0.995). The limits of detection and limits of quantitation were 0.03–3.48 μg/kg and 0.10–11.59 μg/kg, respectively. The average recoveries at 3 spiked levels (low, medium and high) ranged from 76.3%–119.6%, with relative standard deviations of 0.45%–9.02%. The established method was applied to the analysis of 62 batches of Dimocarpus longan Lour. and its dried products and 16 kinds of mycotoxins were detected in 21 samples, with the average contents ranging from 0.42–13.51 μg/kg.

The established method is simple in operation, high in sensitivity and accurate in results, which is suitable for high-throughput screening and quantitative detection of 50 kinds of mycotoxins in Dimocarpus longan Lour. and its dried products.

To select a strain that effectively inhibits the growth of Aspergillus flavus.

Effective strains were screened using the streak plate method and the confrontation culture method of Aspergillus flavus. The species of the effective strain was determined through morphological observation and 16S rRNA gene analysis. The effect of the effective strain in inhibiting the growth of Aspergillus flavus was verified through experiments of Aspergillus flavus infecting corn and peanut kernels. By using transcriptome sequencing technology, the fermentation broth of the effective strain G10 was co-cultured with Aspergillus flavus for different periods of time, in order to determine the interaction mechanism between the effective strain and Aspergillus flavus.

The strain G10 that inhibited the growth of Aspergillus flavus was selected. It was identified that the effective strain G10 had a 99.93% similarity in the 16S rRNA gene with Burkholderia stagnalis. It belonged to the Burkholderia stagnalis and was named Burkholderia stagnalis G10. The application experiments on infecting corn and peanut kernels had verified that strain G10 had a significant antagonistic effect against Aspergillus flavus. Transcriptome sequencing revealed that the number of differentially expressed genes in strain G10 when co-cultured with Aspergillus flavus for 24 hours was 3341, among which 1830 genes showed up-regulation and 1511 genes showed down-regulation. The number of differentially expressed genes when co-cultured for 48 hours was 5334, among which 2429 genes showed up-regulation and 2905 genes showed down-regulation. Enrichment analysis revealed important gene ontology (GO) entries such as metabolic process, cell process, cell structure components, catalytic complex, etc., and important Kyoto encyclopedia of genes and genomes (KEGG) pathways such as carbon metabolism, amino acid biosynthesis, ribosome generation process, protein processing process, etc.

The selected effective strain G10 can effectively inhibit the growth of Aspergillus flavus, providing a reference for further research on the interaction mechanism between bacteria and Aspergillus flavus and the application of biocontrol bacteria.

To establish a method for the determination of multiple mycotoxins in wheat and its products by direct extraction-ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

Samples (2 g) were extracted with 10 mL 80% acetonitrile-water solution (containing 1% formic acid).After ultrasonic extraction, centrifugation, nitrogen blow-drying and reconstitution, the analytes were detected using an electrospray ionization (ESI) source in both positive and negative ion modes. Quantification was performed using the external standard method calibrated with a wheat flour matrix-matched standard curve.

The linear relationship of the 7 kinds of mycotoxins was good within a certain mass concentration range, with a determination coefficient (r²) greater than 0.998. The limits of quantitation were 0.40–7.70 μg/kg. The spiked recovery rates at the 3 levels were 77.9%–109.2%, and the relative standard deviations were 0.9%–9.0% (n=6).

The method has excellent precision and high sensitivity, it is suitable for the determination and high-throughput screening of mycotoxins in wheat and its products.

To evaluate commercially available rapid test products for aflatoxin B₁ based on the entropy weight method-technique for order preference by similarity to an ideal solution coupling model(EW-TOPSIS).

Rapid test products of different brands for aflatoxin B₁ were tested under multi-dimensional conditions involving different application environments, different operators and different food matrices. The 3 indicators, namely sensitivity, false negative rate and false positive rate, were examined. EW-TOPSIS analysis was performed, in which objective weighting through the entropy weight method was employed to eliminate subjective bias, and then the TOPSIS method was combined to calculate the closeness of products to the ideal solution for ranking. The comprehensive performance of 3 brands was systematically evaluated, and ultimately a complete and scientific evaluation system for AFTB₁ rapid test products was established.

The weights of sensitivity, false negative rate and false positive rate determined by the entropy weight method were 0.3377, 0.3377 and 0.3247, respectively. The ranking of the 3 brands based on the closeness coefficient was brand A (0.8597)>brand B (0.6136)>brand C (0.4214). A higher closeness coefficient indicated better comprehensive performance; therefore, Brand A was identified as the optimal one, which remained stable under extreme temperatures and with different operators, exhibiting outstanding performance in accuracy, specificity, and applicability, followed by brand B and brand C in descending order.

This model is applicable for the comprehensive evaluation of rapid test products of various brands and matrices, providing a basis for product selection at the grassroots level and quality control by regulatory authorities, while also offering a novel approach for the evaluation of rapid test products and promoting the standardized application of rapid test technology in the field of food safety.

To establish a method for the simultaneous determination of 16 kinds of mycotoxins in noodles by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

Samples were ground into powder and extracted with an acetonitrile-formic acid-water solution (70:1:29, V:V:V). The extract was centrifuged, diluted, filtered and analyzed by UPLC-MS/MS. Chromatographic separation was performed on an ACQUITY UPLC® BEH C₁₈ column (2.1 mm×100 mm, 1.7 μm) using a gradient elution with mobile phases consisting of acetonitrile and 0.2% formic acid-water solution. Detection was carried out using electrospray ionization in positive/negative switching mode with multiple reaction monitoring, and quantification was performed using the external standard method.

The 16 kinds of mycotoxins showed good linearity within their respective concentration ranges, with correlation coefficients (r) ranged from 0.9986 to 0.9999. The limits of quantitation ranging from 0.0516 to 105.2628 μg/kg. The recovery rates in their corresponding μg/kg-level spiked samples ranged from 92.7% to 124.4%, and relative standard deviations ranged from 1.95% to 9.32%. Among 30 samples of fresh wet noodles and 30 samples of dry noodles, the detection of rate deoxynivalenol was 100%, the concentration ranged from 21.200 to 229.000 μg/kg, with no significant difference (P>0.05) between fresh wet and dry noodles. The contamination level of aflatoxin B₁ in dry noodles was significantly higher than that in fresh wet noodles (P<0.05). Conversely, the contamination levels of fumonisin B₂ and zearalenone were significantly higher in fresh wet noodles than in dry noodles (P<0.001).

This study establishs a method for the simultaneous and rapid detection of 16 kinds of mycotoxins in noodles. Compared with previously reported methods and national standard methods for mycotoxins detection in food, this method is characterized by simpler operation, faster analysis, lower cost, higher sensitivity and better accuracy. It is well-suited for rapid screening in noodles and their raw materials (wheat flour), providing reliable technical support for contamination monitoring and risk assessment of related foods.

To determine the best medium composition and fermentation conditions to maximize the production of exopolysaccharides from Lentinula edodes through submerged fermentation, as well as to analyze the structure and assess the antioxidant properties of the extracted exopolysaccharides.

Single-factor experiments were conducted to identify the optimal carbon and nitrogen sources and their concentrations. Furthermore, 3 key factors influencing the yield of Lentinula edodes exopolysaccharides—pH, liquid volume and agitation speed were selected for response surface methodology optimization under controlled fermentation parameters (pH, liquid volume, rotation speed, inoculum size and fermentation time). The exopolysaccharides produced under these optimized conditions were characterized using scanning electron microscopy, ultraviolet spectroscopy, infrared spectroscopy and thermogravimetric analysis. Their ability to scavenge free radicals, including 1, 1-diphenyl-2-trinitrophenylhydrazine(DPPH), 2, 2-biazo-di (3-ethyl-benzothiazolin-6-sulfonic acid) diammonium salt, and hydroxyl radicals, was also evaluated.

Glucose at 20 g/L and yeast extract at 5 g/L were identified as the optimal carbon and nitrogen sources, respectively, for submerged fermentation of Lentinula edodes. The ideal fermentation parameters were pH 6, liquid volume of 101 mL, agitation speed of 149 r/min, inoculum size of 5% and an 8-day fermentation period. Scanning electron microscope images showed that the exopolysaccharides had a loose structural morphology. Ultraviolet spectroscopy revealed no absorption peaks indicative of nucleic acids or proteins, while infrared spectroscopy displayed characteristic polysaccharide absorption bands at 3408.1, 2920.5, 1646.1 and 1324.5 cm^–1. Thermogravimetric analysis demonstrated that the polysaccharides maintained good thermal stability between 28 ℃ and 180 ℃. The exopolysaccharides exhibited strong antioxidant activity, with scavenging rates of 60.14% for DPPH radicals, 53.47% for ABTS cationic radicals and 93.94% for hydroxyl radicals.

The study optimize the submerged fermentation process for producing exopolysaccharides from Lentinula edodes, confirming the method’s stability and practicality. These findings provide a theoretical foundation for enhancing fermentation efficiency, increasing polysaccharide yields and supporting further development and application of Lentinula edodes polysaccharides.

To establish a method for the simultaneous determination of trace elements in Pyrus sinkiangensis Yu and Qiuli lung moistening paste by pressure tank digestion and inductively coupled plasma mass spectrometry (ICP-MS).

The samples were digested in a pressure tank at 80 ℃ for 2 h, 120 ℃ for 2 h and 165 ℃ for 4 h, and then analyzed by ICP-MS. The accuracy and reliability of the method were evaluated through methodological studies.

The linear relationship of each element was good within a certain range (r>0.9996)based on the results of the methodological studies. The relative standard deviations (RSDs) of precision were 0.03% to 8.32%, indicating good instrument precision. The RSDs of repeatability were 0.03% to 3.17%, indicating good repeatability. Both Pyrus sinkiangensis Yu and Qiuli lung moistening paste contained 16 kinds of trace elements including beryllium, boron, titanium, vanadium, chromium, manganese, cobalt, nickel, copper, zinc, gallium, arsenic, strontium, cadmium, barium and lead. Pyrus sinkiangensis Yu contained more lithium than Qiuli lung moistening paste. The content of 8 kinds of elements including titanium, vanadium, chromium, manganese, cobalt, nickel, zinc and cadmium in Qiuli lung moistening paste made from Pyrus sinkiangensis Yu was higher than those in the main raw material.

This method requires a small sample size, has a low limit of detection, high sensitivity and accuracy, and can be used for the simultaneous determination of multiple Pyrus sinkiangensis Yu.

To optimize the process conditions for the preparation of Juglans regia L. antioxidant peptides by echelon enzymatic hydrolysis.

Juglans regia L. antioxidant peptides were prepared from defatted Juglans regia L. powder by alkaline protease, neutral protease and acid protease in a consecutive manner. The enzymatic hydrolysis process was optimized by single factor combined with orthogonal experiment and response surface method with antioxidant activity and hydrolysis degree as indexes.

The optimum process of neutral protease was enzymatic hydrolysis temperature 51 ℃, pH 6.87, substrate concentration 5%, enzyme addition 28000 U, enzymatic hydrolysis time 3 h. The optimum process of acid protease was enzymatic hydrolysis temperature 50.0 ℃, pH 5, substrate concentration 5.0%, enzyme addition 30000 U, enzymatic hydrolysis time 3 h. The degree of hydrolysis was 43.74%, the cation radical scavenging rate of 2, 2’-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) was 92.14%, and the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) scavenging rate was 87.55%.

This study optimizes the protein echelon enzymatic hydrolysis process, which can be used as a feasible strategy for the preparation of Juglans regia L. antioxidant peptides.

To optimize the extraction process of walnut flower polysaccharides and explore its potential regulatory effect on intestinal flora.

Walnut flower polysaccharides was extracted by enzyme-assisted deep eutectic solvent method. Based on single-factor experiments, response surface methodology was employed to optimize the extraction parameters with moisture content, enzyme concentration, extraction temperature and liquid-to-solid ratio as independent variables. Fourier transform infrared spectroscopy and ultraviolet spectrophotometry were employed for the preliminary structural characterization of walnut flower polysaccharides.Furthermore, in vitro fermentation experiments were conducted to analyze the effects of walnut flower polysaccharides on the diversity, structure and short-chain fatty acids (SCFAs) production of hyperlipidemia-related intestinal microbiota. The correlation between microbiota and SCFAs was elucidated using a correlation heatmap.

The optimal extraction conditions were determined as follows: moisture content of 30%, enzyme concentration of 2%, extraction temperature of 50 ℃, and liquid-to-solid ratio of 21:1 (mL:g). Under these conditions, the extraction yield of walnut flower polysaccharides reached (5.91±0.42)% and the established model exhibited reliable predictive ability. The polysaccharide content of the extracted walnut flower polysaccharides was determined to be 88.03%. Structural characterization indicated that WFP contained uronic acid groups and pyranose ring structures, as well as both α- and β-glycosidic bonds. In vitro fermentation results showed that walnut flower polysaccharides significantly improved the diversity and structural composition of the intestinal microbiota, promoted the proliferation of beneficial bacteria, inhibited the growth of pathogenic bacteria and increased the production of SCFAs including acetate, propionate and butyrate. Correlation analysis indicated that the aforementioned beneficial genera were strongly positively correlated with core SCFAs, which could serve as biomarkers for the recovery of intestinal beneficial metabolic functions.

The extraction process of walnut flower polysaccharides is feasible and walnut flower polysaccharides exhibits regulatory effects on the intestinal microbiota. This study provides a theoretical basis for the development of functional foods in the field of intestinal health.

To analyze the content of dehydroacetic acid (DHA) in wet rice flour products in Hubei Province from 2024 to 2025 and assess the exposure levels of residents.

From 2024 to 2025, 218 samples of wet rice and flour products sold in 7 cities of Hubei Province were collected by random sampling. The content of DHA in the samples was detected by high-performance liquid chromatography according to GB 5009. 121—2016 National food safety standards-Determination of dehydroacetic acid in food and the DHA exposure level was evaluated using a point assessment model.

The overall content of DHA in wet rice and flour products in Hubei Province from 2024 to 2025 ranged from ND to 0.855 g/kg, with an average value of 0.119 g/kg. The overall detection rate of DHA was 32.1%, and the overall exceedance rate was 4.6%. There were statistically significant differences in the content, detection rate and exceedance rate of DHA in different years, types of wet rice and flour products (P<0.01). Compared with other years, the highest mean DHA content was observed in the first half of 2024(0.290 g/kg), the highest detection rate also in the first half of 2024 (72.5%), and the highest exceedance rate in the first half of 2025 (9.8%). The average content of DHA (0.270 g/kg) and the detection rate (59.6%) were the highest for wet rice noodles. The P₉₅ value of DHA content (0.731 g/kg) and the exceedance rate (18.2%) were the highest for wide noodles. There were statistically significant differences in the content and detection rate of DHA in rice noodles, cold noodles and rice flour products in different years (P<0.05). The average content and detection rate of DHA in these three foods were the highest in the first half of 2024 and then decreased year by year. There were statistically significant differences in the DHA exposure levels in different years (P<0.01). The average and P₉₅ values of DHA exposure levels decreased first and then increased over the years, with the highest exposure level in the first half of 2024. The average and P₉₅ values of DHA exposure levels in urban areas were higher than those in rural areas.

The content of DHA in wet rice and flour products in Hubei Province from 2024 to 2025 is low, and the exposure level is also relatively low. Relevant departments need to pay special attention to the excessive use of DHA in cold noodles and rice noodles.

To assess the dietary exposure risk of cyanide in fruits and processed fruit products sold in Jiaxing City in 2025.

The content of cyanide in fruits (expressed as hydrocyanic acid) and processed fruit products was detected by gas chromatography referring to GB 5009.36—2023 National food safety standard-Determination of cyanide in food. The dietary exposure risk was evaluated by using the point assessment model and the hazard quotient method, combined with the average consumption of various foods for residents of different age groups.

A total of 90 fresh fruit samples were analyzed and the overall positive rate was 16.7%, with concentrations ranging from not detected to 0.690 mg/kg and an average of 0.0465 mg/kg. Among the 50 fruit processed products (21 fruit wines, 19 fruit juices and 10 fruit jams), the overall positive rate was 56.0%, with total detected values ranging from ND to 6.98 mg/kg, and an average value of 0.681 mg/kg. The average chronic dietary exposure amounts of cyanide in fruits, fruit juices, fruit wines and fruit jams for different gender and age groups were 0.0514, 1.0200, 1.2300 and 0.0218 μg/kg bw·d, respectively, all of which were lower than the maximum allowable daily intake value of 20 μg/kg bw·d for hydrogen cyanide.

Risk assessment indicates that while the intake risk from processed fruit products is higher than that of fresh fruits, both remain within safe limits. However, due to their lower body weight, children were identified as a sensitive group with relatively higher acute and chronic exposure estimates, warranting specific attention.

To understand the content of trace elements in the livers and kidneys of sheep and pigs sold in some areas of Inner Mongolia and evaluate their safety.

Randomly selected the livers and kidneys of sheep and pigs from the marketplaces and supermarkets in some areas of Inner Mongolia. After microwave digestion, determined the content of lead, cadmium, total arsenic, total mercury, barium, copper, manganese, selenium, chromium and nickel using inductively coupled plasma mass spectrometry. Statistical analysis was conducted, exposure risk assessment was carried out in combination with single-factor pollution index, target hazard index and carcinogenicity index.

There were significant differences in the content of manganese, selenium, copper and cadmium in the kidneys and livers (P<0.05); there were significant differences in copper, total arsenic and selenium in sheep liver and pig liver (P<0.05); there were no significant differences in the content of 10 kinds of elements in sheep kidney and pig kidney (P>0.05). The copper pollution index in sheep liver, the single-factor pollution index of selenium in pig liver and pig kidney were greater than 1, reaching the severe pollution level; the comprehensive pollution index of heavy metals such as Nemerol in pig liver, pig kidney and sheep liver was at a slightly polluted level. The comprehensive pollution index of heavy metal Nemerol in sheep kidneys was 0.59, which was within the safety level. The cumulative target hazard coefficient and carcinogenicity coefficient were both within the safe range.

The overall levels of harmful heavy metal elements in the liver and kidneys of sheep and pigs in the Inner Mongolia region are relatively low, with only 3 samples exceding the cadmium limit. cadmium.The content of trace elements is abundant, but the copper content in the liver and the selenium content in the kidneys are too high, posing potential food safety risks. Further identification of the pollution source is necessary, along with continuous monitoring and risk assessment. By studying the content of trace elements in the liver and kidneys of sheep and pigs in the Inner Mongolia region and evaluating their safety, this research aims to guide people in reasonable dietary combinations and ensure the reasonable intake of trace elements.

To establish a method for the determination of acetochlor, metolachlor and propisochlor residues in green soybeans, soybeans and soybean oil, and to investigate the interference of structurally related compounds on the quantification of acetochlor quantified as its metabolites.

Residues of the 3 kinds of parent herbicides were determined by QuEChERS pretreatment combined with ultra performance liquid chromatography-tandem mass spectrometry. On the basis of the same extract, alkaline hydrolysis and liquid-liquid extraction procedures were introduced, and an analytical strategy for hydrolytic conversion was established using 2-methyl-6-ethylaniline (EMA) as an indicator, with systematic optimization of hydrolysis and cleanup conditions.

Good linearity was obtained for the 3 kinds of parent pesticides and EMA within the corresponding concentration ranges. The average recoveries ranged from 77.8% to 106.6%, and the limits of quantitation were all 0.02 mg/kg. Metolachlor and propisochlor could both be converted to EMA under alkaline heating conditions, thereby interfering with the quantification of acetochlor expressed as EMA.

This method can meet the requirements for accuracy, precision and sensitivity in the determination of parent residues of acetochlor, metolachlor and propisochlor, as well as the hydrolysis product EMA, in green soybeans, soybeans and soybean oil.

To establish a method for the simultaneous determination of 13 kinds of flavor compounds in rice by gas chromatography-tandem mass spectrometry (GC-MS/MS).

The sample was extracted with 25% ethanol solution, followed by liquid-liquid extraction using dichloromethane. The lower dichloromethane phase was filtered through anhydrous sodium sulfate and subjected to high-speed centrifugation.Separation was performed on a DB-5MS column (30 m×0.25 mm, 0.25 μm) with a programmed temperature.Detection was carried out under multiple reaction monitoring (MRM) mode, and quantification was achieved via the external standard method with calibration curves prepared using matrix-matched extract.

All 13 kinds of flavor compounds showed good linear relationships within their respective concentration ranges, with correlation coefficients greater than 0.990. The limits of detection and the limits of quantitation were 0.5–5.0 μg/kg and 2.0–20.0 μg/kg, respectively. Spike recovery experiments were conducted at 3 different levels in rice matrices, and the average recoveries were in the range of 81.55% to 115.10%, with the relative standard deviations varying from 1.6% to 6.3%.

The developed method features high sensitivity, accurate qualitative and quantitative results, simplicity and high efficiency, and is suitable for the simultaneous determination of 13 kinds of flavor compounds in rice.

To establish a method for the determination of 19 kinds of sex hormone residues in Pheretima by QuEChERS combined with enhanced matrix removal-lipid (EMR-lipid) and ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

The samples were pretreated using a QuEChERS dispersive solid-phase extraction combined with an EMR-lipid solid-phase extraction cleanup method.Separation was achieved on a Zorbax Eclipse Plus C₁₈ column (3.0 mm×150 mm, 1.8 μm) using a gradient elution with a mobile phase consisting of 0.02% ammonia solution and methanol. Detection was performed by multiple reaction monitoring (MRM) in positive and negative electrospray ionization modes.

The 19 kinds of analytes were showed good linearity within their respective concentration ranges, with correlation coefficients all above 0.999. The average recoveries at 3 spiked levels ranged from 71.39% to 118.78%, with relative standard deviations ranging from 0.90% to 14.33%. The limits of detection were 2.5 μg/kg to 25.0 μg/kg, and the limits of quantitation were 5.0 μg/kg to 50.0 μg/kg.

This method exhibits high specificity and accurate results. It is suitable for the complex matrix of lipid-rich traditional Chinese medicines such as Pheretima and has been successfully applied to the detection of practical samples.

To determine the content of 11 kinds of organic acids (citric acid, malic acid, tartaric acid, succinic acid, maleic acid, lactic acid, acetic acid, tannic acid, fumaric acid, gallic acid and coumaric acid) in green plum wine by high performance liquid chromatography (HPLC) and the chemical pattern recognition analysis is performed.

The analysis was performed using HPLC with a CAPECELL PAK ADME C₁₈ (4.6 mm×250 mm, 5 μm)column, where mobile phase A was methanol and mobile phase B was a 0.1% (V:V) aqueous phosphoric acid solution.Gradient elution was employed at a column temperature of 30 ℃, with a detection wavelength of 210 nm. The results were subsequently analyzed using chemopattern recognition software, specifically SPSS 25.0 and SIMCA 14.1.

The 11 kinds of organic acids exhibited excellent linearity (r≥0.9993) within their respective mass concentration ranges, with average addition recovery ranging from 92.69% to 104.35% and relative standard deviations of 0.29% to 4.72%. Cluster analysis of 9 batchs samples revealed 3 distinct groups when Euclidean distance was set to 5. Principal component analysis identified 3 major components, consistent with cluster results: the first principal component included tartaric acid, malic acid, tannic acid, citric acid, succinic acid and fumaric acid; the second principal component comprised acetic acid and gallic acid; while the third principal component consisted of lactic acid, maleic acid and coumaric acid. Orthogonal partial least squares discriminant analysis identified citric acid and malic acid as potential flavor difference markers.

The method is simple, accurate and sensitive, and is suitable for qualitative and quantitative analysis and evaluation of organic acids in green plum wine and other foods.

To establish a method for simultaneous determination of Cr, Cu, As, Cd, Hg and Pb in Sanghuangporus spp. by microwave digestion-inductively coupled plasma mass spectrometry.

Nitric acid was used as the only digestion reagent, the appropriate proportion of Au element was selected as mercury stabilizer, and ¹⁰³Rh was used as the single internal standard element for correction.

The correlation coefficients of the 6 kinds of heavy metal elements were not less than 0.999, and the method limits of detection were 0.00009-0.00090 mg/kg.The relative standard deviations (RSDs) of each element content in the sample ranged from 1.79% to 7.26%, and the recoveries of 2 different concentrations ranged from 92.2% to 105.2%. The certified reference material of astragalus(GSB–19) was detected by this method, and the measured values were all within the range of standard values, with RSDs ranging from 1.54% to 6.04%.

The method is accurate, reliable, rapid, efficient and reagent saving, and is suitable for the analysis and detection of heavy metal elements in Sanghuangporus spp..

To determine of γ-aminobutyric acid (GABA) in suancai fermentation broth by high performance liquid chromatography with diode array detection (HPLC-DAD) coupled with pre-column derivatization with dansyl chloride.

In this study, HPLC-DAD was used to perform real-time online spectral scanning of derivatives. Combined with single factor experimental method, the derivatization reaction conditions and chromatographic separation parameters were systematically optimized.

Using NaHCO₃-Na₂CO₃ as buffer system, 45 ℃ water bath derivatization reaction for 5 min, and without ammonia, the derivatization effect was the best, but the sample pH still needed to be adjusted to more than 10 when determining the suancai fermentation broth. The mobile phase with 0–15 min, 30%–42% acetonitrile, 70%–58% 20 mmol/L phosphoric acid could not only achieved a stable baseline, but also made the target and interferents baseline separation. when the organic mobile phase changed from methanol to acetonitrile, the derivative λ_max changed from 219 nm to 222 nm, that was the λ_max shifted red. At the wavelength of λ_max(222 nm), coefficient of determination reached 0.99999, with the highest sensitivity and the lowest limit of detection (0.023 mg/L), which revealed that λ_max was the optimal detection wavelength. The method validation results showed that the optimized method exhibited a good linear relationship within the mass concentration range of 0.05–100.00 mg/L. The limit of detection of the method was 0.074 μg/mL, and the limit of quantitation was 0.241 μg/mL. The recovery rate was 87.02%–107.25%, with a relative standard deviation of 2.34%–3.49%. Furthermore, it was found that GABA had poor stability and should not be stored for extended periods even under refrigeration.

The optimized method can be used to determine GABA in suancai fermentation broth with complex matrices, demonstrating good sensitivity, precision and reproducibility. It is also confirmed that ammonia can induce derivative side reactions, changes in the organic mobile phase can cause changes in λ_max, and the GABA has poor stability.

To establish a method for determining the purine content in prepackaged solid beverages by high performance liquid chromatography and to apply it to the analysis of commercially available ones.

The 4 kinds of purines were extracted from solid beverages using acid hydrolysis. Chromatographic columns were screened based on resolution and peak shape. Detection conditions, including mobile phase pH, flow rate and column temperature, were optimized, and method validation was performed.

Using a Sunniest C₁₈ column, a mobile phase of 10 mmol/L ammonium formate solution at pH 3.68 methanol (99:1, V:V), a flow rate of 1.0 mL/min, a column temperature of 30 ℃, an injection volume of 10 μL, and a detection wavelength of 254 nm, the 4 kinds of purines were completely separated with good peak shapes. Guanine, adenine and hypoxanthine exhibited good linearity in the range of 1–40 mg/L (r²≥0.9990), while xanthine showed good linearity in the range of 0.1–4.0 mg/L(r²=0.9998); the limits of detection were 0.01–0.14 mg/L, and the limits of quantitation were 0.04–0.46 mg/L;spiked recovery rates were 88.00%–113.00%, with relative standard deviations were 0.05%–5.90%. The purine content in the 11 kinds of milk tea samples ranged from 6.66 mg/100 g to 30.46 mg/100 g, and in the 11 kinds of coffee samples, it ranged from 5.28 mg/100 g to 26.11 mg/100 g.

This method exhibits good precision and accuracy and can be used for the simultaneous determination of 4 kinds of purines in solid beverages, providing a scientific basis for dietary choices among individuals with hyperuricemia and gout.

To systematically evaluate the nutritional composition and quality characteristics of different commercially available brands of ready-to-cook grilled fish.

Ready-to-cook grilled fish samples from 8 different brands were collected, and variations in indicators including basic composition, amino acids, fatty acids, sensory evaluation, total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARs), color, shear force and water-holding capacity were analyzed.

There were significant differences in the moisture, crude protein, crude fat and ash content among the 8 brands of grilled fish (P<0.05). The amino acid composition of roasted fish was consistent, with essential amino acids (EAA)/total amino acids (TAA) at 0.45, and EAA/non-essential amino acids (NEAA) ranging from 0.81 to 0.83. This met the standard for high-quality protein. The ready-to-cook grilled fish contained unsaturated fatty acids (UFA) accounting for 78% of the total fatty acids, content of oleic acid and linoleic acid was relatively high. Regarding quality characteristics, the comprehensive sensory scores of HY-1 to HY-4 were superior to those of HY-5 to HY-8. The TVB-N (5–8 mg/100 g) and TBARs (<2.2 mg/kg) of the 3-month stored samples were all well below the established limits, indicating good freshness and compliance with safety standards.Significant differences in color, shear force and water-holding capacity were observed among the ready-to-cook grilled fish products from different brands (P<0.05), which could be attributed to variations in raw materials and processing parameters. The results of low-field nuclear magnetic resonance indicated that there were significant differences in the content of immobilized water and free water among different brands. The grilled fish samples exhibited pronounced signals for nitrogen oxides, methyl compounds, sulfides, alcohols, aldehydes/ketones and organosulfur compounds, along with analogous principal component profiles.

The 8 brands of ready-to-cook grilled fish maintain well-preserved nutritional value, freshness and edible safety, while variations in raw materials and processing techniques among different brands give rise to significant product differences. This study aims to scientifically evaluate the overall quality of commercially available ready-to-cook grilled fish, clarify the current situation and challenges of ready-to-cook grilled fish, and provide a scientific basis for promoting the high-quality development of the ready-to-cook grilled fish industry.

To develop a nanozyme-based immunochromatographic test strip with high sensitivity for rapid identification of bovine milk or goat milk adulteration in camel milk, utilizing the property that nanozymes can catalyze substrates to amplify detection signals.

The competitive method was adopted to develop the immunochromatography test strip. The rabbit antibody (Ab) of β-casein labeled with cobalt iron oxide (CoFe₂O₄)nanozyme was sprayed onto the binding pad. The β-casein antigen and mouse anti-rabbit immunoglobulin G (IgG) were respectively coated on the detection line (T line) and the control line (C line) of the nitrocellulose membrane to assemble the nanozyme immuno-chromatographic test strip. The nanozyme test strip was evaluated for consistency, sensitivity, limit of detection and specificity with the commercial colloidal gold immuno-chromatographic kit.

The nanozyme strip demonstrated a sensitivity of 5 μg/mL for antigen detection, which was 200 times higher than that of the commercial colloidal gold strip (1000 μg/mL). The limit of detection was 0.02% (capable of detecting cow milk diluted up to 5000 times), demonstrating a significant advantage over commercially colloidal gold strips with a limit of detection was 0.1%. It exhibited excellent specificity and achieved 100% consistency with the commercial colloidal gold strip.

This method is simple to operate, and can quickly screen out adulteration in camel milk on the spot.It has higher sensitivity than the commercial colloidal gold reagent strip.

To establish a qualitative and quantitative analytical method for determination of 6 kinds of microplastics (MPs) in packaged drinking water by pyrolysis-gas chromatography-mass spectrometry.

Diatomaceous earth was used as a diluent, and cryogenic grinding technology was applied to prepare 6 kinds of solid MPs standard substances. Characteristic pyrolysis product ions corresponding to each MPs were identified using pyrolysis-gas chromatography-mass spectrometry, serving as the basis for qualitative and quantitative analysis. The established method was subsequently applied to determine MPs in commercially available packaged drinking water.

Characteristic pyrolysis product ions for the 6 kinds of MPs were successfully identified. The constructed quantitative calibration curves all exhibited good linearity, the limits of detection were 0.10–1.10 μg/L, the spiked recovery rates were 65.2%–89.5% and the relative standard deviation was less than 10%. Polystyrene, polyethylene, polyethylene terephthalate (PET), and polyvinyl chloride were detected in 8 kinds of commercially available packaged drinking water samples, with polyethylene terephthalate being the most abundant.

The pyrolysis-gas chromatography-mass spectrometry pretreatment method established in this study is simple and efficient, featuring high sensitivity and good repeatability. It is suitable for the quantitative detection of MPs in packaged drinking water

To optimize the curing process for ready-to-cook Pampus argenteus using response surface methodology.

The Pampus argenteus was cured in a brine solution, and the process parameters were optimized. The effects of brine concentration, curing time and curing temperature on the quality of Pampus argenteus were investigated. Based on single-factor experiments, the curing process for ready-to-cook Pampus argenteus was optimized using response surface methodology with sensory score as the response value.

According to indicators such as sodium chloride content and cooking loss rate, the optimal curing parameters were determined as follows: curing concentration of 4.2%, curing time of 2.75 h, and curing temperature of 15 ℃±1 °C. The sensory score of the cured ready-to-eat Pampus argenteus was 4.2. While significantly increasing the moisture content of the fish(from 74.6 g/100 g to 80.1 g/100 g), the process had little effect on the basic nutritional composition of the product, and the salt content remained within a controllable range.

This process effectively preserves the original nutritional components of Pampus argenteus when used for processing cured ready-to-eat Pampus argenteus, yielding a product with good appearance and desirable texture. The results provide a technical reference for the processing of cured ready-to-eat Pampus argenteus.

To analyze the characteristics and origin of one food-derived ST45 methicillin-resistant Staphylococcus aureus (MRSA) strain and evaluate its pathogenicity.

This study conducted antimicrobial susceptibility testing, whole genome sequencing and analysis, hemolytic activity, biofilm formation ability and the lethality of the food source ST45-MRSA (SAV15) to comprehensively assess its potential threat. Using the genomic data of Staphylococcus aureus included in the National Center for Biotechnology Information database (NCBI), the ST45 Staphylococcus aureus dataset was constructed. A phylogenetic tree was established based on single nucleotide polymorphism analysis to trace the food source SAV15.

The foodborne SAV15 exhibited resistance to cefoxitin, oxacillin, penicillin and erythromycin, carrying multiple resistance genes including mecA, erm(C) and blaZ.SAV15 harbored hemolysin genes (hla, hlb and hld) and adhesion-related factors (clfAB and icaABCDR), exhibiting strong biofilm formation capacity. Notably, its lethality in Galleria mellonella showed no significant difference compared to the hypervirulent USA300 and bloodstream infection strains (P>0.05). Phylogenetic analysis revealed that SAV15 belongs to the Chinese ST45-MRSA lineage and carries multiple human immune evasion cluster genes, such as chp, scn and sak. These findings suggested that the foodborne SAV15 likely originated from human carriers through contamination of the food chain via horizontal transmission.

Human-origin ST45-MRSA may be horizontally transmitted through food chain contamination. Strengthening the surveillance of MRSA within the food chain is essential to provide data support for food safety and public health policy-making.

To establish a method for the simultaneous determination of dichloroacetic acid (DCAA)and nitrite in water by suppressed ion chromatography, and optimize their separation conditions through response surface methodology.

Thermo Scientific Dionex IonPac™ AS19 anion exchange column was used. Taking the separation degree of DCAA and nitrite as the core evaluation index, the effects of 3 key factors (column temperature, DCAA concentration and eluent concentration) on the separation degree were investigated by single-factor experiments. Building upon this, a Box-Behnken central composite design was employed to construct a response surface model, thoroughly exploring the interactions between the factors and determining the optimal separation conditions.

The optimal separation conditions obtained by response surface methodology were as follows: column temperature 25 ℃, DCAA mass concentration 1000 μg/L and eluent mass concentration 6 mmol/L (with nitrite mass concentration fixed at 100 μg/L as the experimental background). Under the optimized conditions, the separation degree between DCAA and nitrite reached 2.71, meeting the requirement for effective separation of components during detection. Methodological validation results demonstrated good linearity within a certain concentration range(determination coefficient r²>0.999), the relative standard deviations were below 3.5%, and spike recovery rates were 95%-107%. These findings indicated that the method possessed high accuracy and stability.

The detection method optimized in this study can effectively achieve simultaneous and accurate determination of DCAA and nitrite in water. It is characterized by simple operation, high efficiency and reliability, making it suitable for the routine monitoring of these 2 kinds of substances in actual drinking water. This provides strong technical support for water quality safety assessment.

To investigate the contamination status of Listeria monocytogenes in the production and processing of Flammulina velutipes in Lianyungang City.

Samples were collected from the production and processing chain of Flammulina velutipes in Lianyungang City. Isolation, identification and multilocus sequence typing of Listeria monocytogenes were performed.

A total of 67 samples were positive for Listeria monocytogenes among 359 samples collected from the production and processing chain of Flammulina velutipes, with an overall detection rate of 18.66%. The differences in the detection rate of Listeria monocytogenes among different sampling years and sampling locations were statistically significant (P<0.05), whereas no significant difference was observed among different sample types (P>0.05). The contamination rate in 2024 was relatively high(24.71%), and the positive detection rate of samples from the mycelium scraping room (38.46%) was much higher than that from other sampling sites. Environmental samples showed the highest contamination rate (25.32%).Sequence typing (ST) of the 67 Listeria monocytogenes isolates revealed that ST87 (32 isolates) and ST8 (31 isolates)were the dominant sequence types.

Listeria monocytogenes contamination exists in the production and processing chain of Flammulina velutipes in Lianyungang City, with the scraping room and harvesting and packaging area being the most heavily contaminated sites. It is essential to strengthen monitoring and supervision in these links, and formulate targeted prevention and control measures focusing on highly contaminated areas and environmental management.

To investigate the extraction efficiency of Pteris vittata polysaccharides via an ultrasound-assisted cellulase method, and explore its hypoglycemic and hypolipidemic activities.

Response surface methodology was applied to optimize the technical parameters for the ultrasound-assisted cellulase extraction of Pteris vittata polysaccharides. The in vitro hypoglycemic activity was evaluated by determining the inhibition rates of α-amylase and α-glucosidase activities, while the in vitro hypolipidemic activity was assessed by analyzing the inhibition rate of pancreatic lipase activity as well as the binding rates to sodium glycocholate and sodium taurocholate.

The optimal extraction parameters for Pteris vittata polysaccharides were determined as follows: solid-liquid ratio of 1:20 (g:mL), cellulase dosage of 2.2%, ultrasonic power of 316 W, ultrasonic temperature of 51 ℃ and ultrasonic time of 22 min. Under these conditions, the extraction yield of Pteris vittata polysaccharides was measured to be 4.19%±0.08%. In vitro bioactivity assessment demonstrated that Pteris vittata polysaccharides possessed certain hypoglycemic and hypolipidemic biological activities. The half-maximal inhibitory concentrations (IC₅₀) of Pteris vittata polysaccharides against α-amylase and α-glucosidase were 3.52 mg/mL and 2.75 mg/mL, respectively. Its IC₅₀ against pancreatic lipase was 4.08 mg/mL, and the half-maximal effective concentrations (EC₅₀) for glycocholate and taurocholate were 4.45 mg/mL and 4.38 mg/mL, respectively.

The ultrasound-assisted cellulase method can efficiently extract Pteris vittata polysaccharides. Pteris vittata polysaccharides are potential functional food material with hypoglycemic and hypolipidemic properties.

To investigate the types and differences of volatile compounds in ethyl ester-type fish oil after the addition of different adsorbents.

The carbon tube composite adsorbent was characterized using a scanning electron microscope (SEM). The quality of ethyl ester-type fish oil was evaluated by determining its acid value, peroxide value and p-anisidine value. Gas chromatography-ion mobility spectrometry (GC-IMS) combined with multivariate statistical analysis was applied to screen the key volatile compounds in ethyl ester-type fish oil treated with different adsorbents.

SEM analysis confirmed the stability of the carbon nanotube-activated carbon composite structure; after treatment with the carbon tube composite adsorbent, the quality of ethyl ester-type fish oil complied with GB 5009. 229—2025 National food safety standard-Determination of acid value in foods, GB 5009.227—2023 National food safety standard-Determination of peroxide value in foods, GB/T 24304—2024 Animal and vegetable fats and oils-Determination of anisidine value; GC-IMS analysis detected a total of 53 kinds of volatile compounds, including 11 kinds of aldehydes, 10 kinds of alcohols, 8 kinds of ketones, 7 kinds of esters, 6 kinds of alkenes and 11 kinds of other compounds. Combined with orthogonal partial least squares discriminant analysis and variable importance in projection, GC-IMS screening finally identified 14 kinds of key volatile substances, namely (E, E)-2, 4-nonadienal, N-nitrosodimethylamine, 2-butanone (D), (Z)-3-hexenol, ethanediol (D), (E, E)-2, 4-heptadienal (D), decanal, 1-butanol, 3-methyl-1-butanol, ethanediol (M), ethyl propionate (M), (E, E)-2, 4-heptadienal (M), 3-penten-2-one (M) and camphene.

This study clarifies the regulatory rules by which a novel new type carbon tube composite adsorbent the flavor compounds in ethyl ester-type fish oil, providing scientific guidance for optimizing the refining process of ethyl ester-type fish oil, as well as theoretical support and practical evidence for the development of new adsorbent materials.