Objective To study the change of benzoic acid content in water extract of Paeoniae Radix Alba after decocting, and the influence of different decocting time on the content of benzoic acid. Methods The raw materials were decocted separately or in combination, and concentrate to a density of 1.15-1.20, the content of benzoic acid in the water extract after decocting and concentrating was determined by high performance liquid chromatography. Results Benzoic acid content was not detected (limit of quantification was 0.01 g/kg) in Paeoniae Radix Alba, the benzoic acid content in concentrated liquid of paeony increased to 2.91-3.77 g/kg after single decocting, and the benzoic acid content after two-stage decocting ranged from 3.26 g/kg to 4.02 g/kg. The content of benzoic acid in the mixed concentrate containing Paeoniae Radix Alba was 0.542 g/kg. Benzoic acid was not detected in others. Conclusion The content of benzoic acid in water extract of Paeoniae Radix Alba increased after high temperature decocting, and it's proportional to time. Therefore, when preparing food or health products with Paeoniae Radix Alba as the main raw material, attention should be paid to the control of decocting temperature and time, and the factory inspection of this item should be increased to prevent the harm caused by high content of benzoic acid.

Objective To establish a method based on real-time fluorescent polymerase chain reaction (PCR) for the identification of the genus Cipangopaludina and Bellamya, and identify the snail-derived ingredients in the meat soup package of river snail rice noodle. Methods Specific primers and probes were designed using mitochondrial genes from the genera Cipangopaludina and Bellamya, respectively. The effectiveness of the established real-time fluorescence PCR method was evaluated for its specificity, sensitivity and repeatability. Results The real-time fluorescence PCR identification method developed in our study exhibited strong specificity, detecting fluorescence signals only in the designated channel for the DNA of the Cipangopaludina and Bellamya, with typical amplification curves observed. No fluorescence signals were detected in the designated channel for the genomic DNA of various heterogeneous animals and plants, including aquatic products, poultry, livestock, and spice and seasoning raw materials, with no observable amplification curves. The method demonstrated sensitivity as low as 0.002 ng/μL for Cipangopaludina and 0.001 ng/μL for Bellamya. The method was employed to analyze DNA extracted from snail meat soup packets in 21 batches of prepackaged river snail rice noodle across various brands in supermarket distribution. In 7 batches of prepackaged river snail rice noodle from different brands, Cipangopaludina components were detected in the DNA of the snail meat soup packets, representing 33.3%. In 18 batches of prepackaged river snail rice noodle from different brands, Bellamya components were detected in the DNA of the snail meat soup packets, representing 85.7%. In 3 batches of prepackaged river snail rice noodle from different brands, neither Cipangopaludina and Bellamya components were detected in the DNA of the snail meat soup packets, accounting for 14.3%. In 7 batches of prepackaged river snail rice noodle from different brands, both Cipangopaludina and Bellamya components were detected in the DNA of the snail meat soup packets, representing 33.3%. Conclusion This method boasts strong specificity and high sensitivity, effectively identifying snail-derived components in snail meat soup packets of river snail rice noodle, thereby providing robust technical support for market regulation.

Objective To establish a detection method for simultaneously detecting 9 kinds of biogenic amines in aquatic products using the dansyl chloride precolumn derivazation-reverse phase high performance liquid chromatography. Methods The samples were extracted with a 5% trichloroacetic acid solution and derivatized with a 10 mg/mL dansyl chloride acetone solution. The derivatization reaction was terminated with ammonia, and the resulting solution containing the dansyl chloride derivatives of the 9 kinds of biogenic amines was made up to volume with acetonitrile. The sample solution was analyzed by reverse phase liquid chromatography using a C₁₈ column, with a mobile phase gradient of acetonitrile and water, and detected at 254 nm using a ultraviolet detector. Results The limits of quantitation of the 9 kinds of biogenic amines in aquatic products ranged from 1.08 to 7.59 mg/kg, with recovery rates ranging from 85.2% to 106.7% and precision ranging from 1.5% to 4.9%. The established method was used to analyze 50 batches of high-histamine fish sold in Guangzhou. The results revealed that the overall quality of the high-histamine fish in Guangzhou was good. β-phenylethylamine and cadaverine had relatively higher detection rates compared to other biogenic amines, but their content was all below 35 mg/kg. Histamine, putrescine, spermidine, agmatine, and arginine were not detected. Conclusion The method is fast, simple, and highly sensitive, making it suitable for batch sample determination of the 9 kinds of biogenic amines in aquatic products.

Objective To establish a vegetable safety risk prediction model based on the particle swarm optimization (PSO) algorithm and the stacked generalization (Stacking) model, and to predict the sampling results of fenthion in vegetables sold in Shanghai. Methods Based on the sampling data of fenthion in vegetables sold in Shanghai from 2021 to 2023, task type, sampling area, sampling link, sampling place, sampling month, testing institution, and vegetable variety were selected as feature variables. The target variable was whether the sampling results for fenthion in vegetables were qualified. The PSO-Stacking prediction model was constructed using ten-fold cross-validation to select effective machine learning models and resampling methods and optimized the model parameters using the PSO algorithm. Results Fenthion-positive samples were found in 55 out of 3889 vegetable samples, with an overall failure rate of 1.4%. Bean vegetables had the highest rate at 2.3%, followed by eggplant and fruiting vegetables at 0.2%. The base models were obtained through screening, including Random Forest (RF), categorical boosting (CatBoost), gradient boosting (GB), extreme gradient Boosting (XGBoost), and light gradient boosting machine (LGBM). The best resampling technique was adaptive synthetic sampling (ADASYN). The PSO-Stacking model achieved the highest precision (0.91), recall (0.83), F1 score (0.87), and area under the curve (AUC) value (0.91) on the test set. Conclusion The PSO-Stacking model effectively addresses imbalanced food safety sampling data, accurately predicts the unqualified fenthion samples in vegetables, and provides technical support for vegetable supervision, sampling and risk warning.

Objective To investigate the solvent effect differences in the extraction of substances from flower discs of Helianthus annuus L. using non-targeted metabolomics technology, and to explore the impact of different solvent extraction methods on the metabolic composition of flower disc of Helianthus annuus L.. Methods Liquid chromatography-mass spectrometer (LC-MS) combined with non-targeted metabolomics was utilized to preprocess and statistically analyze the data. Results The study revealed that lipids and lipid-like molecules constituted the largest proportion of metabolites (21.5%), followed by shikimate and phenylpropanoid metabolites (13.4%), and organic heterocyclic compound metabolites (11.1%). Further identification led to the discovery of 8407 kinds of up-regulated and 1054 kinds of down-regulated metabolites, highlighting significant differences in metabolite composition resulting from various extraction methods. The main differential metabolites between the 2 kinds of solvent extraction methods encompassed lipids, shikimate and phenylpropanoids, terpenoids, etc., involving 96 metabolic pathways, with 20 pathways exhibiting significant differences. Based on fold change (FC), using criteria of log₂(FC)>0.6 or -0.2<log₂(FC)<0, and P<0.05 to screen for significantly differential metabolites between alcohol and water extracts, only 11 substances had a log₂(FC) value less than 1, indicating that alcohol extraction significantly increased the content of bioactive components extracted from the flower disc of Helianthus annuus L.. Conclusion The research method is simple and reliable, confirming the importance of non-targeted metabolomics analysis in studying solvent effect differences in flower disc of Helianthus annuus L.. It provides a novel approach for the analysis of flower disc of Helianthus annuus L. products and offers theoretical support for the subsequent development of health foods and pharmaceuticals.

Objective To establish a method for the determination of 11 kinds of residues of benzimidazole drugs in freshwater fish and shrimp by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods The samples were first extracted by acetonitrile twice, purified by mixed strong cationic solid phase extraction column, then separated by Waters C₁₈ column, detected by UPLC-MS/MS, and the internal standard method was adopted for quantitative analysis. Results The 11 kinds of benzimidazole drugs showed good linear relationships at 1.0-50.0 μg/L, with correlation coefficients (r²) greater than 0.99. The ranges of spiked recovery rates for 3 concentrations of blank fish samples were between 78.4% and 104.3%, and the relative standard deviations of the recovery rates for 3 concentrations were between 2.0% and 8.8%; the recovery rates of 3 concentrations of shrimp meat blank samples ranged from 73.3% to 107.5%, with relative standard deviations between 1.5% and 8.7%. The limit of detection of the method in this study was 0.5 μg/kg, and the limit of quantification of the method was 2.0 μg/kg. Conclusion The method has good purification effect, stable reproducibility and recovery, and is suitable for the determination of 11 kinds of benzimidazole residues in freshwater fish and shrimp.

Objective To study the effects of deep eutectic solvent (DES) on the absorbance of tea polysaccharide by visible spectrophotometry, and establish a fast and efficient method for the determination of tea polysaccharide. Methods Choline chloride/DL-tartaric acid was used as the extraction solvent of tea polysaccharide. The influence of DES on the determination of tea polysaccharide content in anthrone sulfuric acid and phenol-sulfuric acid 2 kinds of detection methods was investigated. The linear relationship, precision, stability, repeatability and standard recovery rate of the 2 kinds of detection methods were compared. Results The best method for the determination of tea polysaccharides was phenol-sulfuric acid method, the optimal detection wavelength was 484 nm, and the absorbance had a good linear relationship with glucose concentration between 20 and 100 μg/mL. The precision relative standard deviation (RSD) of this method was 0.10%, the stability RSD was 0.00%, the repeatability RSD was 2.40%, and the recovery rate was 94.25%-111.19%, and the content of tea polysaccharide was 54.76 mg/g. Conclusion Phenol-sulfuric acid method is suitable for the determination of tea polysaccharide in tea with DES as extraction solvent.

Objective To establish an analytical method for the determination of 6 kinds of Sudan dyes in Capsicum annuum powder based on liquid-liquid microextraction with deep eutectic solvents (DES) combined with high performance liquid chromatography. Methods Sudan red I, Sudan red II, Sudan red III, Sudan red IV, Sudan red 7B and Sudan red G in Capsicum annuum powder were extracted by liquid-liquid microextraction. The extract was filtered through a microporous membrane and then determined by high performance liquid chromatography with external standard method for quantification. The effects of DES dilution ratio, DES molar ratio, DES addition amount, extraction time, and extraction method on the extraction efficiency of 6 kinds of Sudan dyes were investigated. Results The results showed that the optimal method conditions were: Dilution ratio of DES 5 times, molar ratio of DES 1:2.5, addition amount of DES 600 μL, extraction time 50 s, and extraction method was vortex extraction. Under these conditions, the established equation had a good linear relationship in the range of mass concentration 0.1-50.0 mg/L, the correlation coefficients were all greater than 0.999, the limits of detection were 0.03-0.20 mg/kg, and the limits of quantitative were 0.10-1.00 mg/kg. The recovery rates of Sudan red G, Sudan red I, and Sudan red II were higher, ranging from 71.6% to 117.5%, with relative standard deviations of 0.6% to 4.7%. Conclusion The established method is simple, efficient, and environmentally friendly, and can be used for rapid detection of 6 kinds of Sudan dyes in Capsicum annuum.

Objective To investigate the type and drug resistance characteristics and virulence gene carrying of some food-borne methicillin-resistant Staphylococcus aureu (MRSA) in Ningxia. Methods MRSA isolates from some food risk monitoring in Ningxia were collected and subjected to drug susceptibility testing, pulsed-field gel electrophoresis (PFGE), and whole-genome sequencing analysis respectively. Results PFGE typing of 9 food-borne MRSA strains was divided into 3 clusters and 8 kinds of types, all of which were more than 85% provenance. ST typing of the whole genome sequencing results was divided into 4 kinds of ST types, 6 strains were ST59, and the other 3 strains were ST3355, ST7 and ST965, respectively. MRSA were all multi-drug resistant, which carrying different resistance genes and virulence genes, resulting in different drug resistance phenotypes. Conclusion Foodborne MRSA isolates have a large number of genes related to antibiotic resistance and pathogenicity, which pose a significant threat to human health. Therefore, it is of great importance to continuously monitor and take effective measures to reduce the contamination level of MRSA in food to ensure food safety.

Curdlan, a type of microbial extracellular polysaccharide, is widely utilized as a food additive due to its exceptional gelling, water-holding, thickening, and freeze-thaw stability properties within food systems. In recent years, the research on the regulation of the interaction between curdlan and biomacromolecules has become a research hotspot in the field of food science, aiming at optimizing the texture of food, enhancing the stability of food, and promoting the development of new healthy foods. However, a systematic summary of the interaction between curdlan and biological macromolecules, as well as their regulatory mechanisms is still insufficient at present. As a result, this review offered a comprehensive overview of recent research progress in the interaction between curdlan and biomacromolecules, particularly emphasized the interactions between curdlan and polysaccharides, proteins and other macromolecules in food applications. This review aims to establish a theoretical foundation for the precise design and innovative development of functional foods.