Objective To investigate and analyze a food poisoning incident caused by bongkrekic acid (BA) in Xiaogan City, Hubei Province, isolate and identify the pathogenic bacteria, and detect the toxin. Methods Ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to measure BA levels in 2 exposed food samples (cold rice noodles), 3 food storage environment samples, and 2 patient blood samples. Following GB/T 4789.29—2020 Microbiological examination of food hygiene—Examination of Burkholderia gladioli (Pseudomonas cocovenenans subsp. farinofermentans), microbial identification was performed on 2 exposed food samples and 3 environmental samples, including isolation and culture, matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry, 16S rDNA sequencing, real-time quantitative polymerase chain reaction (PCR) analysis, and toxin production experiments. Results The BA concentrations in the 2 patients’ blood samples were 92.2 μg/L and 1059.0 μg/L, respectively. The BA content in the unsold and frozen cold rice noodles was 2.26 mg/kg and 0.39 mg/kg, respectively, while no BA was detected in the environmental samples. Two suspected strains were isolated from the implicated food. VITEK MS MALDI-TOF MS and 16S rDNA sequencing identified both strains as Burkholderia gladioli. Real-time quantitative PCR and toxin production experiments confirmed that both strains could produce BA and tested positive for the bon gene, indicating toxigenic potential. They were comprehensively identified as Burkholderia gladioli pathovar cocovenenans. No Burkholderia gladioli was detected in the environmental samples. Conclusion This food poisoning incident is caused by cold rice noodles contaminated with Burkholderia gladioli pathovar cocovenenans. Relevant authorities need to strengthen food safety supervision to prevent similar poisoning incidents.

Objective To establish and optimize conditions for the determination of octachlorostyrene residues in milk by high performance liquid chromatography (HPLC) method. Methods Milk samples were extracted with acetonitrile and cleared up by sodium chloride and anhydrous magnesium sulfate, filtered through a microporous membrane, and analyzed by the high performance liquid chromatography. The separation was performed on a Waters C₁₈ column (250 mm×4.6 mm, 5 μm) with gradient elution by using 0.3% trifluoroacetic acid solution (pH=3.2) and acetonitrile (20:80, V:V) as the mobile phase, and quantified by external standard method. Results The results indicated that the correlations were greater than 0.999 at the range of 0.1 to 2.0 ng/mL. The limit of detection of octachlorostyrene was 0.05 μg/kg, and the limit of quantitation was 0.1 μg/kg. The average recoveries of octachlorostyrene ranged from 70% to 90% at spiled levels of 0.1 to 0.4 μg/kg with relative standard deviation less then 10%. Conclusion The experiment show that the method is simple, rapid, high sensitivity, good reproducibility and suitable for detection of octachlorostyrene residues in milk. The method provide effective technical support to the government’s food and agricultural product quality supervision work.

Objective To study and develop edible flower resources, evaluate their nutritional components and in vitro antioxidant activities. Methods The 6 kinds of edible flowers—Kanzan flower, loquat flowers, roses, chrysanthemums, jasmine flowers and honeysuckle—were selected as study subjects. The content of polysaccharides, polyphenols, total flavonoids, free amino acids, proteins, cyanidin and petunidin in the samples were measured. Principal component analysis and correlation analysis were used to compare the antioxidant activity of different edible flowers. Results The chemical compositions of the 6 kinds of edible flowers showed significant differences. The free amino acid (11.18%) and protein (22.06%) content of Kanzan flower were significantly higher than those of the other 5 kinds of flowers. The polysaccharide content of the 6 kinds of flowers was concentrated around 4%. The highest polyphenol and total flavonoid contents were found in roses (9.42%-13.94%) and Guangxi honeysuckle (3.62%), respectively. Petunidin and cyanidin were detected in Kanzan flower, loquat flowers, and roses. Except for Pingyin roses, the petunidin and cyanidin contents in roses were generally higher than those in Kanzan flower and loquat flowers. Antioxidant experiments showed that roses exhibited strong scavenging effects on 2,2-diphenyl-1-picrylhydrazyl radicals and hydroxyl radicals. Correlation analysis indicated that polyphenols, petunidin and cyanidin in edible flowers were positively correlated with antioxidant activity, with correlation coefficients all greater than 0.72, while no significant correlation was observed between total flavonoid content and free radical scavenging rates. Principal component analysis and comprehensive scoring revealed that roses ranked highest among the 6 kinds of flowers. Conclusion Overall, roses possess higher nutritional value as a food ingredient compared to the other five edible flowers. The research provide a scientific basis for the selection of food materials and the development of new food products in the field of edible flowers.

Objective To investigate the difference of hydrogen isotope ratio between whole grains and cereals flour and their components and the influence of drying conditions and moisture on the determination of hydrogen isotope ratio in grains and cereals. Methods High temperature cracking/elemental analysis-stable isotope ratio mass spectrometry (TC/EA-IRMS) was used to determine the δ²H values of whole grains and cereals flour (maize, rice, wheat and sorghum) and the fractions (starch, defatted portion, fat, crude fiber and protein). The effects of different drying conditions on the δ²H values of grain were analyzed, and the influence of exchangeable hydrogen on the determination of starch hydrogen isotope ratios was explored. Results The δ²H values of various fractions in the grains and cereals were different. Drying the grain samples at 105 °C to a constant weight was the best water removal effect. After being treated with different standard water samples under the optimal drying conditions, the maximum difference in δ²H of grains and starch was 12.11‰ and 18.41‰. This indicates that exchangeable hydrogen had a significant effect on the δ²H value of starch (P<0.001). Conclusion The isotopic fractionation of sugar, fat, protein and cellulose during the growth of grain makes the distribution of hydrogen isotopes in samples not uniform. Organic compounds contain exchangeable hydrogen, which will exchange isotopes with the water in the environment where the sample is located, affecting the accurate analysis. When measuring the hydrogen isotope ratio in grain, it is necessary to exclude the interference of water. This study provides an effective reference for the determination of hydrogen isotope ratios in grain starch and the study of grain traceability in the future.

Objective To optimize the brewing process of Grossedentata tea flavored beer and evaluate its effect on reducing uric acid. Methods With Grossedentata tea and malt as the main raw materials, the brewing process of Grossedentata tea flavored beer was optimized through single-factor experiments and response surface optimization experiments. Meanwhile, the physical and chemical indicators of Grossedentata tea flavored beer, such as alcohol content, diacetyl, total phenols, and total flavonoids, were determined. A high-uric-acid mouse model was established through animal experiments to detect the uric acid levels and liver function and other biochemical levels of mice after consuming Grossedentata tea flavored beer and ordinary beer, and to evaluate the uric acid-lowering effect of Grossedentata tea flavored beer. Results The optimal brewing process of Grossedentata tea flavored beer was 10 g/L of Grossedentata tea powder, 28% of malt addition, and 4% of yeast addition. Under these conditions, the alcohol content of this beer was 1.57%vol, the diacetyl content was 0.08 mg/L, the total phenol content was 12.41 mg/mL, the total flavonoid content was 86.12 μg/mL, the pH was 4.4, and the sugar content was 7°Brix. Animal experiments indicated that compared with ordinary beer, Grossedentata tea flavored beer could reduce serum uric acid, hepatic xanthine oxidase activity, and hepatic malondialdehyde levels. Compared with the positive control group, the activity retention of hepatic superoxide dismutase and catalase was higher, and it could reduce the content of pro-inflammatory factors, restore the level of anti-inflammatory factors, and had less side effects on the liver than the positive control group. Conclusion Grossedentata tea flavored beer has a clear and bright color, harmonious aroma, rich foam, delicate taste, and a tea aroma aftertaste. The overall sensory experience conforms to the public taste and has the health care effect of reducing uric acid.

Objective To use coleslaw at the retail-to-consumption level as a source of contamination with Staphylococcus aureus, assess the health risk posed to residents of Jilin Province and identify the key contributing factors. Methods Based on the monitoring data of Staphylococcus aureus in coleslaw in Jilin Province from 2011 to 2019, combined with the data of residents’ coleslaw consumption and temperature, a prediction model of Staphylococcus aureus growth was established. The results were analysed and Monte Carlo simulated using @Risk8.0 software, and a quantitative risk assessment of Staphylococcus aureus in commercially available coleslaw in Jilin Province was carried out in 4 parts: Hazard identification, exposure assessment, hazard characterization and risk analysis. Results The data statistics showed that the initial contamination rate of Staphylococcus aureus in coleslaw was 3%, and the average contamination was -2.37 log10CFU/g, with a 95% confidence interval of (-5.88, 1.27) log10CFU/g. The assessment results showed that the probability of triggering Staphylococcus aureus intoxication was 0.1%, and the number of cases of illness that could be caused by Staphylococcus aureus was 154500 cases per year. Conclusion The initial level of Staphylococcus aureus contamination in coleslaw is most important in causing the risk of Staphylococcus aureus infection, follow by storage temperature. Keeping the source ingredients, preparation environment clean and hygienic, and having good refrigerator use habits are important measures to reduce the risk of developing Staphylococcus aureus infections in coleslaw.

Objective To establish a method for the simultaneous determination of quinolones antibiotics (enrofloxacin, ciprofloxacin, norfloxacin, pefloxacin, ofloxacin, lomefloxacin) and doxycycline residues in prepared dishes by high performance liquid chromatography tandem mass spectrometry. Methods The 84% acetonitrile aqueous solution (1% ice acetic acid) was used as extraction solution, Oasis Prime-HLB solid phase extraction column was used to purify and concentrate, all the eluents were collected, nitrogen-blown to nearly dry, and 1 mL of complex solution 10% methanol aqueous solution (containing 1% ice acetic acid) was added to vortex dissolve, and 0.22 μm microporous filter membrane was taken as supernatant. The Waters ACQUITY UPLC TM BEH C₁₈ column (100 mm×2.1 mm, 1.7 μm) was separated, methanol and 0.1% formic acid aqueous solution were used as mobile phase, ionization mode was spray positive ion mode, and the analysis was performed by high performance liquid chromatography tandem mass spectrometry using multiple reaction detection mode. Results The linear correlation of the 7 kinds of antibiotics was good (r>0.9990). The limits of detection were 0.03-0.24 μg/kg and the limits of quantitatation were 0.09-0.72 μg/kg. The recoveries were 84.5%-114.0% and the relative standard deviations were 1.1%-4.1%. Conclusion The method established in this study is convenient, rapid, accurate and stable, and can be used for quantitative analysis of 6 kinds of quinolone veterinary drug residues and doxycycline residues in prepared dishes.

Owing to the high protein content, low fat levels, and rich amino acid profile of Bos grunniens meat, market demand has been steadily increasing. Due tohigh breeding costs, low production yields, and widespread adulteration practices have hindered the industrial development of Bos grunniens meat. Analysis technologies have played a crucial role in ensuring the safety of the supply of Bos grunniens meat products. This paper reviewed the analytical techniques applied to Bos grunniens meat assessment over the past 20 years, namely chromatography, mass spectrometry (MS), biological and spectroscopic techniques. In particular, chromatography, MS and their coupled techniques had proven effective in characterizing the composition and structure of Bos grunniens meat. Biological techniques, notably polymerase chain reaction (PCR) technology, DNA sequencing (DNA-seq), and related methods, were applicable to species identification and genetic analysis. Furthermore, immunoassay (IA) demonstrate high sensitivity in monitoring veterinary drug residues, whileloop-mediated isothermal amplification (LAMP) could be employed for adulterant detection. Spectroscopic techniques exhibited outstanding performance in compositional analysis, freshness evaluation and geographical origin tracing. The integration of chemometrics with spectroscopic techniques showed great promise forrapid analysis and accurate identification of Bos grunniens meat components, driving the evolution of Bos grunniens analysis toward eco-friendly, non-invasive and automated paradigms. It provides comprehensive technical references and theoretical support for quality improvement, market supervision, scientific research, and the sustainable development of the Bos grunniens industry.

Objective To establish 2 kinds of methods for the determination of 17-pentatriacontene in honey by gas chromatography-flame ionization detection (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Methods After dissolved in water, the sample was extracted with petroleum ether, purified on a florisil cartridge, separated by DB-5MS column (15 m×0.25 mm, 0.25 μm), and determined by GC-FID and GC-MS, then quantified by external standard method. Results The GC-FID and GC-MS were quantified using matrix-free standard curve and matrix-matched standard curve respectively, with limits of quantification of 1.0 mg/kg and 0.5 mg/kg, linear ranges of 1-100 mg/kg and 0.5-40.0 mg/kg, and recovery rates ranging from 88.9% to 94.5% and from 91.2% to 98.2%, respectively. The relative standard deviations were 4.0%-6.4% and 4.6%-7.3%, respectively. The results of the 2 kinds of methods were basically consistent, with a relative deviation of no more than 2.4%. The proposed methods were applied to 158 honey samples of Apis cerana honey and Apis mellifera honey, 17-pentatriacontene was only detected in Apis cerana honey, with a content range of 0.58-51.10 mg/kg. Conclusion The accuracy and precision of the GC-FID and GC-MS methods established in this study are both good, and the 2 kinds of methods can be applied to the determination of 17-pentatriacontene in honey. The results of real sample tested indicate that 17-pentatriacontene can be used as a characteristic marker for Apis cerana honey.

Objective To quantitatively analysis and comprehensively evaluate the active component content and nutritional value of hybrid Gastrodia elata and its parent varieties. Methods A combination of ultra performance liquid chromatography, automatic amino acid analyzer and Dumas nitrogen analyzer was employed to conduct a quantitative analysis and comprehensive evaluation of their active component contents and nutritional values. One-way analysis of variance was performed using SPSS. Results The hybrid Gastrodia elata exhibited significant advantages in active component content. For instance, the total content of gastrodin and p-hydroxybenzyl alcohol in WH03 reached 1.082%, with a parishin content of 0.750%, both significantly higher than those of the parent varieties. In terms of nutritional value, the total amino acid content and protein content of hybrid Gastrodia elata were also superior to those of the parent plants. Specifically, the hybrid Gastrodia elata WH03 exhibited a total amino acid content of 7.604% and a protein content of 10.12%. Conclusion This study establishes a chemometrics-based comprehensive evaluation model for Gastrodia elata quality, revealing the chemical quality improvement patterns of hybrid strains, and provides critical scientific evidence for the genetic improvement and industrial development of Gastrodia elata.