Objective To establish a method for the determination of 17α-estradiol and 17β-estradiol in aquatic products by QuEChERS combined with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods The sample was extracted with water-acetonitrile (2:8, V:V), purified with N-propylethylenediamine, C₁₈ and neutral alumina, blown to dryness with nitrogen, and then reconstituted with water-acetonitrile (8:2, V:V). The sample solution was analyzed using water and acetonitrile (both containing 5 mmol/L ammonia) as mobile phase, separated by C₁₈ chromatographic column, scanned and detected in multiple reaction monitoring (MRM) mode, and quantified by external standard method. Results The results showed that 17α-estradiol and 17β-estradiol showed a good linear relationship in the concentration ranges of 5 to 200 μg/L, and the correlation coefficients were 0.9998 and 0.9985, respectively. The average recoveries at three spiked concentration levels varied from 66.5% to 101.1% with relative standard deviations of 0.62% to 10.17%. The limit of detection was 0.85-0.90 μg/kg, and the limit of quantitation was 2.1-2.4 μg/kg. Conclusion This method is simple, fast, sensitive and accurate, suitable for qualitative and quantitative analysis of 17α-estradiol and 17β-estradiol in aquatic products such as fish, shrimp, crabs and shellfish.

Objective To establish an analytical method for the simultaneous determination of 8 kinds of organophosphate ester flame retardants of major meat and cereal food products by QuEChERS purification technology coupled with ultra performance liquid chromatography-tandem mass spectrometry. Methods Separation was achieved on a Agilent EC-C₁₈ column (3 mm×150 mm, 2.7 μm) with a mobile phase consisting of 0.1% formic acid aqueous solution and acetonitrile under gradient elution at a flow rate of 0.4 mL/min. Detection was performed in positive electrospray ionization (ESI+) mode with multiple reaction monitoring (MRM). Results The 8 kinds of organophosphate ester flame retardants exhibited good separation and showed excellent linearity in the range of 1.0-50.0 ng/mL, with correlation coefficients all greater than 0.99. The limits of detection and limits of quantitation were 1.0 μg/kg and 2.0 μg/kg, respectively. The recoveries of this method were 70.0%-119.6%, and the relative standard deviations were 0.2%-12.7%. Conclusion The established method is simple, rapid and highly efficient in extraction, and has been successfully applied to the analysis of organophosphate ester flame retardants in food samples (including cereals and meat products).

Objective To analyze the content characteristics of 5 kinds of heavy metals including lead (Pb), cadmium (Ca), total arsenic (As), total chromium (Cr), and total mercury (Hg) in Arachis hypogaea L. sold in Anhui Province, and to establish risk assessment of dietary exposure based on consumption data. Methods A total of 80 Arachis hypogaea L. samples were collected from 16 cities in Anhui Province. The content of Pb, Ca, As, Cr and Hg in Arachis hypogaea L. samples were determined using inductively coupled plasma mass spectrometry (ICP-MS). The Nemerow comprehensive pollution index were applied to evaluate the heavy metal pollution status in Arachis hypogaea L.. Combined with the consumption survey data on Arachis hypogaea L. consumption of residents in Anhui Province from 2015 to 2017, to analyze the exposure of various population groups in Anhui Province to heavy metals via Arachis hypogaea L. consumption, and the health effects were evaluated. Results Among the 80 Arachis hypogaea L. samples, the detection rates of Pb, Cd, As, Cr and Hg were 92.5%, 100.0%, 100.0%, 93.8% and 7.5%, respectively. Except for Cr, which had an over-limit rate of 5.0%, all other elements remained within the acceptable limits. The difference was statistically significant (P<0.05). The single-factor pollution index of samples collected from Huainan City and Chuzhou City was greater than 0.7. Males aged 18-50 years had the highest Cr EDI [0.0622 μg/(kg·d), P_97.5=0.413 μg/(kg· d)]. The margin of exposure (MOE)/margin of safety (MOS) values of the 5 kinds of heavy metal elements in Arachis hypogaea L. were all greater than 1. The MOS value of the Cr element from 18-50 aged was lowed than 10, while the MOS values of Cd in were the lowest. Conclusion The detection rates of 5 kinds of heavy metals in Arachis hypogaea L. in Anhui Province are high, but the over-limit rates are low. Cr levels exceeds standards in certain localized areas, while Cd pollution indices varied across different sampling stages. The health risks from heavy metal exposure through Arachis hypogaea L. consumption are determined to be at acceptably low levels for local residents.

Objective To investigate the contamination of fusarium and alternaria toxins in wheat and wheat flour in Shaanxi Province. Methods A total of 140 samples of wheat and wheat flour were randomly collected in circulation of 9 cities from 2022 to 2024. Deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-AcDON), 15-acetyldeoxynivalenol (15-AcDON), nivalenol (NIV), zearalenone (ZEN), tenuazonic acid (TeA), alternariol (AOH), alternariol monomethyl ether (AME) and tentoxin (TEN) were determined by high performance liquid chromatography-tandem mass spectrometry. Results The fusarium and alternaria toxins were detected in wheat and wheat flour. The detection rates of DON, 3-AcDON, 15-AcDON, NIV, ZEN, TeA, TEN, AME in wheat were 83.3% (50/60), 5.00% (3/60), 10.0% (6/60), 11.6% (7/60), 8.33% (5/60), 100% (60/60), 100% (60/60) and 98.3% (59/60), respectively. The detection rates of DON, TeA, TEN, AME in wheat flour were 87.5% (70/80), 96.2% (77/80), 88.7% (71/80) and 63.7% (51/80), respectively. A strong positive correlation between DON and 15-AcDON content was demonstrated in the positive samples, so was between TeA and TEN content. The DON dietary exposure was 959.8 ng/(kg·bw·d), which was less than the corresponding tolerable daily intake value. The TeA, TEN, AME dietary exposures were 159.2, 18.1 and 2.30 ng/(kg·bw·d), which were below the corresponding threshold of toxicological concern values in wheat flour. Conclusion Wheat and wheat flour in Shaanxi Province are generally contaminated with fusarium and alternaria toxins from 2022 to 2024, with the highest detection rates of TeA and TEN, following by DON. The fusarium and alternaria toxins exposure risk of wheat flour are within an acceptable risk range.

Foodborne pathogenic bacteria are one of the main causes of foodborne illness, and pose a serious threat to global public health. At present, the detection of pathogenic bacteria in food primarily relies on conventional plate culture method and auxiliary means, such as chromogenic medium and biochemical identification. However, these methods are long-term, cumbersome and prone to false positives, making them inadequate to meet the demands of modern food safety for rapid and accurate detection. Therefore, the development of rapid and effective detection technologies is crucial for the timely detection, control and elimination of bacterial contamination. This paper took several common foodborne pathogenic bacteria, including Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus, as examples to provide a detailed analysis of the principles, applications, advantages and limitations of various detection methods, and discussed the development trend of detection technology in the future. This study provides both theoretical support and practical guidance for enhancing existing detection methods and the developing new rapid detection technologies, with the goal of more effectively tackling challenges related to food safety.

The contamination problem of Bacillus cereus seriously affects the food safety of China, the development of prevention and control technology against Bacillus cereus is urgent. Lactic acid bacteria, as a safe and efficient biological control method, have a good prospect in controlling Bacillus cereus precisely. Previous studies have found that Lactiplantibacillus, Lactobacillus and Lacticaseibacillus are the main genus of antagonistic bacteria. The antibacterial components against Bacillus cereus are mainly bacteriocins, organic acids and extracellular polysaccharides. The antagonistic mechanism mainly included destroying the integrity of cell membrane, inhibiting spore germination, biofilm formation and toxin expression, but the mechanism of internal gene expression regulation is still lack of in-depth exploration. This paper reviewed the progress in controlling of Bacillus cereus by lactic acid bacteria, summarized the lactic acid bacteria species, antibacterial compounds and their antagonistic mechanisms against Bacillus cereus, as well as the applications in food, also prospected the investigation of new types of microbial antibacterial components, the mechanism of action and the future applications, to provide new insights for the development of green prevention and control technologies of foodborne pathogens.

Objective To study the decontamination effects of different photosensitizers combined with blue light irradiation on Porphyra yezoensis. Methods This study first compared the bactericidal effects of 4 kinds of photosensitizers (curcumin, vitamin K3, riboflavin, and sodium copper chlorophyllin) and 3 kinds of wavelengths (405, 420 and 460 nm) on Escherichia coli and Staphylococcus aureus. Two kinds of blue light wavelengths (405 nm and 420 nm) and photosensitizers (curcumin and riboflavin) were then applied to fresh Pyropia yezoensi before drying. The influences of curcumin concentration, irradiation time, and distance were examined. The changes in hygienic indicator bacteria, color difference (ΔE), and nutritional content were measured before and after treatment and drying. Results The decontamination effect on fresh Pyropia yezoensi were consistent with those in the pure bacterial system. Blue light combined with photosensitizers exhibited stronger sterilization efficiency. The optimal treatment was 420 nm blue light combined with 100 μmol/L curcumin (5 cm distance, 150 min). The total viable count and coliforms in untreated fresh Pyropia yezoensi were 5.69 log CFU/g and 4.34 log CFU/g, respectively, which increased to 6.63 log CFU/g and 4.15 log CFU/g after primary drying. Total viable count and coliforms respectively decreased by 1.88 log CFU/g and 1.46 log CFU/g after treatment, and decreased by 1.94 log CFU/g and 1.35 log CFU/g after drying. ΔE of dried Pyropia yezoensi after treatment ranged between 0.5 and 1.5, indicating a slight but noticeable change, while no significant differences (P>0.05) were observed in nutritional components such as vitamin C and vitamin E. Conclusion After treatment with 420 nm blue light and 100 μmol/L curcumin, the total viable count of dried Pyropia yezoensi was reduced to 4.56-4.82 log CFU/g. Apart from slight color difference due to staining, there was no significant change in nutritional components. This study provides technical support for developing a safe, efficient and environmentally friendly preservation and processing method for Pyropia yezoensi.

Objective To develop a rapid and visual method for detecting Shigella by combining loop-mediated isothermal amplification (LAMP) with clustered regularly interspaced short palindromic repeats and associated protein 12b (CRISPR/Cas12b). Methods Based on the conserved invasion plasmid antigen H gene ipaH7 sequence of Shigella, LAMP primers were designed and screened to establish a LAMP method for detection of Shigella. The candidate sgRNAs were designed based on the target DNA sequence of LAMP amplified fragment, and then the sgRNA, which could specifically recognize and stimulate Cas12b cleavage, was screened. Finally, a rapid detection method for detecting Shigella was developed by combining LAMP with CRISPR/Cas12b, and the specificity and sensitivity were evaluated. Results A set of LAMP primers and sgRNA targeting Shigella ipaH7 were screened, and a LAMP CRISPR/Cas12b detection method was established. The detection could be completed within 1 hour with the lowest limit of detection of 1.1×10¹ CFU/mL for pure culture and 1.1×10¹ CFU/g for spiked pork samples, and no cross reactivity with other pathogens. Conclusion This study successfully establishes a rapid, sensitive and visual detection method for Shigella, which can achieve accurate detecting Shigella in food samples.

Objective To explore the bacterial community composition and abundance, as well as inter-sample variations in species composition and community structure in commercially available peanut butter and sesame paste sold in Yunnan Province using 16S rRNA gene sequence analysis. Methods A total of 160 samples encompassing best-selling peanut butter, sesame paste, and mixed spreads from Yunnan Province were subjected to 16S rRNA V4 region amplicon sequencing. Subsequent analyses included species composition profiling, abundance clustering, phylogenetic relationships, and diversity assessments. Results Characteristic sequence analysis revealed that sesame paste contained the highest number of characteristic sequences, followed by peanut butter, while mixed paste had the least. Bacterial community composition analysis indicated that these unique sequences predominantly belonged to the phyla Proteobacteria, Cyanobacteria and Firmicutes. At the genus level, the top 35 identified genera included Listeria, Escherichia-Shigella, Clostridium_sensu_stricto_1, Bacillus, Vibrio, Streptococcus, Pseudomonas and Aeromonas. α diversity analysis demonstrated significant differences in species diversity between peanut butter and sesame paste (P<0.05). Conclusion Distinct bacterial compositions are observed among peanut butter, sesame paste, and mixed spreads, with sesame paste exhibiting the highest species abundance. Among the top 35 identified genera, 12 are known to include pathogenic species, posing potential food safety risks. It is imperative for manufacturers and regulatory authorities to address these concerns to ensure consumer safety. This study provides a reference for food safety regulatory authorities and offered important data support for the establishment of microbiological safety standards for nut butter products.

Objective To analyze the molecular epidemiological characteristics, virulence gene profiles, and distribution of antibiotic resistance genes of Vibrio parahaemolyticus (VP) isolated from foodborne diseases patients in Dalian City, Liaoning Province. Methods A total of 63 VP clinical isolates were collected from Dalian City in 2023. The whole genome sequencing, multilocus sequence typing, virulence genes and drug resistance genes were analyzed, and the clinical epidemiological data were combined for comprehensive analysis. Results July-September was the main epidemic period of VP. The results of sequence type (ST) showed that ST3 was the main epidemic group. The 63 strains carried both tlh and vcrD, and the carrying rate of tdh and vcrD2 virulence genes was 95.24%. All strains carried blaCARB-47, CARB-20, tet (35), tet (34) and CRP resistance genes, and one ST3 strain also carried aminoglycosides, sulfonamides and other resistance genes. There was a certain correlation between virulence gene carrying type and ST type, but there was no obvious clustering feature in the distribution of drug resistance genes. All isolates from patients with systemic symptoms carried tdh and vcrD2. Conclusion ST3 is the main epidemic group of VP in Dalian, Liaoning Province, which is widely distributed and has a high proportion of virulence genes. Speical attention should be paid to the risk of drug resistance transmission of ST3. This study provides a molecular epidemiological basis for the prevention and control of VP.