Silicon is an essential trace element for the human body and generally exists in mineral water in the form of metasilicic acid. The accurate detection of metasilicic acid, a crucial boundary indicator for natural mineral water, is essential for determining compliance within quality standards. The GB 8538—2022 China national food safety standard—Testing methods for natural mineral drinking water specifies 2 kinds of spectrophotometric techniques, the silicomolybdic yellow method and the silicomolybdic blue method, for the detection of metasilicic acid. However, due to factors such as the stability of colorimetric solutions in spectroscopic analysis and differences in absorption wavelengths, the application of these 2 kinds of methods in metasilicic acid detection still presents issues that require further improvement. Researchers have also reported a number of determination methods for metasilicic acid based on different technologies, such as flow injection (FI), inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), ion chromatography (IC), high performance liquid chromatography (HPLC). This article compared the advantages and existing problems of these methods, so as to provide references for the improvement of existing methods and the development of new methods for metasilicic acid determination.

Objective To screen lactic acid bacteria strains with strong ethanol stress resistance and investigate the effects of their biofilms under different ethanol concentrations and environmental disturbances. Methods The growth, biofilm formation, morphological changes and hydrophobicity of various lactic acid bacteria under ethanol stress were examined. The effects of different metal ions and D-galactose on the growth and biofilm formation of lactic acid bacteria were also explored. Results After 48 h of fermentation under 10% ethanol stress, the biomass and biofilm amount of Lacticaseibacillus paracasei were 1.16 and 0.12, respectively. After 24 h of fermentation, its hydrophobicity reached 42.80%, significantly higher than that of Lactiplantibacillus plantarum, Lacticaseibacillus casei, and Limosilactobacillus fermentum, indicating better ethanol stress resistance. Scanning electron microscopy showed that the thickness of the biofilm decreased significantly with increasing ethanol concentration. The addition of D-galactose and metal ions (Ca²⁺, Na⁺) significantly inhibited biofilm formation. Conclusion Lactic acid bacteria resist ethanol stress through biofilm formation, with ethanol stress resistance correlating closely to biofilm production. D-galactose and metal ions affect the growth and biofilm formation of lactic acid bacteria. This study reveals the relationship between ethanol stress resistance and biofilm formation in lactic acid bacteria, provides a theoretical basis and data support for developing lactic acid bacteria biopreparations suitable for high-ethanol food fermentation environments.

Objective To evaluate the quality differences among the main Vitis vinifera L. varieties in Shanghai, identify key quality indicators. Methods A total of 34 batches of Vitis vinifera L. samples were collected from 10 major cultivars cultivated by 7 enterprises in Shanghai. Twelve quality parameters, including cluster weight, berry weight, fructose, glucose, total acid, vitamin C, amino acids, and anthocyanins, were analyzed to assess Vitis vinifera L. quality from 3 perspectives: Physical appearance, intrinsic nutritional quality and overall quality. Results There were significant differences (P<0.05) in the physical appearance, intrinsic nutritional quality and overall quality of Vitis vinifera L. varieties. Shine Muscat performed exceptionally well in sugar-acid balance, Zuijinxiang showed high levels of vitamin C and overall nutritional quality, Jumeigui had a notable advantage in fructose and glucose content, and Shenyuan exhibited the highest total amino acids, though the amino acid composition needs optimization. Principal component analysis revealed that the main factors contributing to quality differences were the sugar-acid ratio, amino acid composition and fruit weight. Conclusion The major Vitis vinifera L. cultivars in Shanghai exhibit distinct quality advantages. Shine Muscat, Zuijinxiang and Jumeigui are particularly suitable for promotion as premium table Vitis vinifera L. varieties. These findings provide a scientific basis for Vitis vinifera L. varieties breeding, cultivation management, and market positioning, while also serving as a reference for consumer health and the development of functional foods.

Objective To understand the metal element contamination in liquid milk in Inner Mongolia region from 2022 to 2023 and assess the metal health exposure risk for the population in Inner Mongolia region. Methods A total of 4103 samples of locally produced liquid milk were collected from Inner Mongolia region. Lead, total mercury, cadmium, chromium and total arsenic were detected using inductively coupled plasma mass spectrometry. The inverno comprehensive pollution index method was used to evaluate the pollution levels of these elements. Considering the actual dietary intake of residents in Inner Mongolia region, the carcinogenic risk assessment (TCR) and non-carcinogenic risk assessment [target hazard quotient (THQ)] were employed to assess the health risks posed by metal elements in liquid milk to the population in Inner Mongolia region. Results In the 4013 samples monitored, all 5 kinds of metal elements were detected. The over-limit detection rate for lead was 22.26% (187/840), for cadmium it was 5.83% (49/840), for total mercury it was 5.12% (43/840), for total arsenic it was 6.54% (55/841), and for chromium it was 40.18% (262/652). Lead, total mercury, and total arsenic all had samples exceeding the limits, with exceedance rates of 5.83% (49/840), 0.119% (1/841), and 0.12% (1/841), respectively. The inverno index for all 5 kinds of metal elements was below 0.7; the TCR for total arsenic and cadmium was less than 10^-4, Within an acceptable risk range; THQ of lead, chromium, and total mercury were all less than 1. Conclusion This study systematically analyzed and comprehensively assessed the sources of heavy metal pollution in liquid milk from different production and processing types, providing a scientific basis for government decision-making, regulation, and the revision of national food safety standards.

Objective To compare the detection results of aflatoxin B₁ (AFB₁) content in various matrices such as rice, wheat products, and peanut products using 2 kinds of different pretreatment methods: Fully automated immunomagentic bead purification and immunoaffinity column pretreatment method. Methods After extraction with methanol:water (70:30, V:V), a portion of the extract was purified using the immunoaffinity column method with an AFB₁-specific immunoaffinity column, while another portion of the extract was processed by a fully automated immunomagnetic bead purification system paired with an immunomagnetic bead kit. Finally, both purified extracts were analyzed using high performance liquid chromatography coupled with post-column derivatization for detection. Results The efficacy of the immunomagetic bead purification kit and the column efficiency of the immunoaffinity column were both greater than 95%, which could meet the experimental requirements. Within mass concentration range of 1.00-50.00 ng/mL, the linear correlation coefficient (r) was 0.99993, indicating a good linear relationship. The 3 level spiked recovery experiments were conducted in rice matrix (n=6), and the recovery rates of the 2 kinds of pretreatment methods ranged from 98.2%-106.0%, with a relative standard deviation range of 1.0%-5.0%; single level spiked recovery experiments were conducted in wheat products (n=6), with a recovery rate exceeding 80% and a relative standard deviation of 3.7%-7.2%. Meanwhile, the 2 kinds of methods were used to detected AFB₁ positive peanut products and the quality control sample of corn flour matrix, their results were subjected to t-test, which showed no significant difference. Further, Bland-Altman statistical analysis was carried out on the results obtained from the quality control samples of corn flour matrix after 2 kinds of pretreatment methods were used. The results showed that the 2 kinds of methods could replace each other in the detection of AFB₁ in this matrix. The purification step of the immunoaffinity column method was time-consuming, 20 batches of samples take about 3-4 hours. And could only be manually operated, which generated about 1000 mL waste liquid; while the immunomagetic bead method used a fully automatic magnetic bead purifier, which automatically completed 20 batches of samples in 40 minutes at one time, with almost no waste liquid generated. Conclusion The fully automated immunomagnetic bead purification method and the immunoaffinity column method both can achieve good results in detecting AFB₁ in various matrices. Also, the immunomagnetic bead purification method is more efficient, easy to handle, generates less waste liquid, and the cost can be reduced by about 50%.

Objective To evaluate the heavy metal contamination characteristics and health risks of Ziziphus jujuba Mill. from 3 major production regions (Jiao cheng Jun Ziziphus jujuba Mill., Tai gu Hu ping Ziziphus jujuba Mill., and Xiang fen Guan tan Ziziphus jujuba Mill.) in Shanxi Province. Methods Sample pretreatment was performed using a microwave digestion system, followed by quantitative analysis of Cr, Ni, Pb, Cd, As, and Hg in 180 Ziziphus jujuba Mill. samples via inductively coupled inductively coupled plasma-mass spectrometry (ICP-MS). Experimental data were standardized using Microsoft Excel 2022, and non-parametric statistical analyses (Kruskal-Wallis H test, Spearman’s rank correlation) were conducted with SPSS 26.0 IBM to investigate elemental distribution patterns and regional correlations. Health risks were assessed using the United States Environmental Protection Agency (USEPA) model with exposure parameters. Results A highly sensitive multi-element simultaneous detection method was established with a limit of detection of 0.003 to 0.010 mg/kg, with a recovery rates of 92% to 108% and a precision of 2.9% to 4.5%. Key findings included: (1) Hg was undetected in all regions, while Cr and Ni were universally detected, Pb detection rates exhibited regional differences, with the highest in Xiangfen, Cd detection rates were notably higher in the Taigu; (2) The studied elements exhibited significant spatial heterogeneity; (3) Pb, Ni and Cr in Jiao cheng Jun Ziziphus jujuba Mill. and Xiang fen Guan tan Ziziphus jujuba Mill. exhibited a highly significant positive correlation, while the correlations of the same elements between Tai gu Hu ping Ziziphus jujuba Mill. and Xiang fen Guan tan Ziziphus jujuba Mill. showed a synchronous enhancement; (4) health risk assessment identified potential non-carcinogenic risks for Cr and Pb in Xiangfen, and the daily intake of As approached but remained below the international threshold. Conclusion This study systematically map the heavy metal contamination profile of Shanxi Ziziphus jujuba Mill. for the first time and propose region-specific grading standards for pollutants, providing a scientific basis for improving the quality and safety regulatory framework of jujube products.

Objective To develop an enzyme-linked immunochromatographic test strip for the determination of amanita toxin in mushroom based on immunochromatography. Methods N-hydroxysuccinimide (NHS) and N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride (EDC) were used as activators, 6-aminohexanoic acid was introduced to obtain amanitin peptide hapten, and further conjugated with keyhole limpet hemocyanin (KLH) and bovine serum albumin (BSA) to prepare immunogen and coating antigen. Then, the immunogen was used to immunize Balb/c mice to prepare monoclonal antibodies. The colloidal gold immunochromatographic test strip for amanitin was successfully developed by preparing colloidal gold and gold labeled antibody, optimizing the concentration of coating antigen, secondary antibody and extracting solution, and then its cross reactivity, stability, repeatability, and accuracy were evaluated. Results The limits of detection of α-amatoxin, β-amatoxin, and γ-amatoxin peptide were 100, 20 and 50 μg/kg, respectively. The sensitivity was 100%, the false positive rate and false negative rate were 0%, and the results were consistent with the existing instrumental methods without cross reaction with other mushroom toxins. Conclusion The test strip has the characteristics of simple operation, high repeatability and good stability, and is suitable for on-sites creening and rapid detection of amanitin in mushrooms.

Objective To establish a visual detection method of Salmonella based on recombinant enzyme polymerase amplification-CRISPR/Cas12a. Methods In this study, recombinase polymerase amplification (PRA) was combined with clustered regularly interspaced short palindromic repeats/associated protein 12a (CRISPR/Cas12a) system. RPA primers and CRISPR-derived RNA (crRNA) were designed and synthesized based on the target invA gene of Salmonella. Fluorescence and test strip methods were employed to read the results. The optimized RPA-CRISPR/Cas12 detection system were evaluated for specificity and sensitivity, and was applied to the detection of food samples. Results Nano gold test strip base on nucleic acid were developed. The established RPA-CRISPR/Cas12 detection method could specifically detecting Salmonella with a sensitivity of 80 CFU/mL within 1.5 h. Used this method to detect 21 kinds of food samples, the results from fluorescence and test strip read were consistent, with a Salmonella detection rate of 4.8%, which was completely consistent with the results of the national standard method. Conclusion The Salmonella RPA-CRISPR/Cas12a visual detection method established in this study has high specificity and sensitivity and is valuable for on-site rapid detection of Salmonella.

The microbiota in the gastrointestinal tract of humans and animals exhibite diverse characteristics, with microbial communities residing in different ecological niches displaying distinct spatial differences, often characterize by high host specificity. In addition to the compositional differences observe along the longitudinal axis of the gastrointestinal tract, microbes also form discrete characteristic communities within specific microenvironments. This review explored how the physical environment of the gastrointestinal tract affaceded the spatial formation and maintenance of microbial communities, the role of diet in shaping the spatial distribution of gut microbiota, and the importance of this spatial heterogeneity in maintaining organismal health. Focusing on the spatial heterogeneity of gastrointestinal microbiota enables a more comprehensive understanding of the adaptive strategies and biological functions of microbes in different locations and local environments in the gastrointestinal tract. This approach contributed to a better understanding of the role of the gut microbiota in health and disease, providing new theoretical foundations for maintaining gut health, preventing and treating diseases, and developing personalized medical strategies.

The safety problem caused by the illegal addition of non edible substances to food has become a major threat to public health. However, there are still some significant limitations in the existing detection technology system, such as blind areas and a lack of detection ability. With the advantages of high-throughput screening and identification of unknown substances, non targeted detection technology has made great progress in the fields of emerging contaminants, multi-residue detection of agricultural and veterinary drugs and among others. This paper introduced the detection techniques of non-edible substances such as spectrum, chromatography and chromatography-mass spectrometry. The principle and application of non targeted detection technology and the application and limitation of non targeted detection screening based on database, mass spectrometry splitting characteristics and metabonomics were described in detail. The problems and challenges of non targeted detection technology in practical application were discussed. And innovatively put forward suggestions to promote the practical transformation of non targeted detection technology and the optimization path based on the fusion of non targeted detection technology analysis strategy and big data algorithm. The purpose of this paper was to provide a theoretical basis for the establishment of an efficient, accurate and green methodology system for non targeted detection of non-edible substances in food.