Objective To establish a quantitative analysis method for determining the content of 5 kinds of lactose derivatives (3'-galactosyllactose, 4'-galactosyllactose, 6'-galactosyllactose, 3'-sialyllactose, 6'-sialyllactose) in milk and dairy products by pre-column derivatization-high performance liquid chromatography. Methods The proteins in milk and dairy products were precipitated. The 5 kinds of lactose derivatives were reacted with 2-aminobenzamide at 55 ℃ for 120 min to label the fluorescent groups. The 5 kinds of lactose derivatives were separated by high performance liquid chromatography with an amide column and quantified by external standard method. Results The 5 kinds of lactose derivatives exhibited good linear relationships within the concentration range of 0.025-5.000 mg/L, with correlation coefficients (r) all exceeding 0.999. The limits of detection and quantification for the 5 kinds of lactose derivatives ranged from 3.5 to 7.5 mg/kg and 12.0 to 25.0 mg/kg, respectively. The recovery rates for the 5 kinds of lactose derivatives were between 90.8% and 103.3%, with relative deviations in detection results ranging from 2.8% to 5.3% (n=3). Conclusion This method demonstrates good precision, recovery rate, and sensitivity, making it suitable for determining the content of 5 kinds of lactose derivatives in milk and dairy products.

Objective To investigate the contamination level of Vibrio parahaemolyticus (VP) in the production chain of the Liuzhou river snails rice noodles, promptly assess the risk of VP in the production chain. Methods From 2023 to 2024, a total of 487 simlpes, including snails and snail meat, semi-finished soup packets, and pre-packed Liuzhou river snails rice noodles final products, were randomly collected from Liuzhou agricultural markets and manufacturing enterprises in Liuzhou. A conbination of culture-based methods and real-time fluorescent polymerase chain reaction (PCR) was used to detect VP. Results Among 70 snails samples from agricultural market with a detection rate of 38.6% and an average contamination level of 16.1 MPN/g in 44 snails samples. In the 41 snails and snail meat sample from manufacturing enterprises showing the detection rate of 2.4%; no VP was detected in the semi-finished soup package or final product. Conclusion Although VP contamination is relatively common in snails at the retail trade, the contamination rate of snails and snail meat in the enterprise is low. Furthermore, the repeated boiling in Liuzhou river snails rice noodles production can effectively control VP. Therefore, the risk of VP contamination in the Liuzhou river snails rice noodles production chain is relatively low.

Objective To rapidly and non-destructively detect aflatoxin in mildly moldy Zea mays using near-infrared spectroscopy (NIRS) technology. Methods Mildly moldy Zea mays samples were selected as experimental materials, with the content of aflatoxin B₁ (AFB₁) as the detection indicator. A total of 153 sample images were collected using the NIRS imaging acquisition system. Three kinds of preprocessing methods, including multiplicative scatter correction, standard normal variate transformation, and moving average smoothing (MAS), were applied to preprocess the raw near-infrared spectral data (RNSD). Backpropagation neural network (BPNN), extreme learning machine, and support vector machine were employed to model and analyze the preprocessed spectral data along with AFB₁ content data, evaluating the impact of preprocessing methods on model performance. Furthermore, the stepwise projection algorithm (SPA) was performed to select characteristic spectra from the preprocessed data for comprehensive comparison after incorporating them into the models. Results The optimal spectral preprocessing method was MAS. Ten characteristic spectra were selected through SPA, and the BPNN model exhibited the best prediction results, achieving a coefficient of determination of 0.932 and a relative prediction deviation of 3.922. This model demonstrated good performance and reliability. Conclusion It is feasible to determine AFB₁ content in mildly moldy Zea mays using NIRS technology. The findings of this study provide an important reference for the application of NIRS in identifying other agricultural products.

Objective To investigate the effects of different storage conditions on the water migration and volatile component changes of Zea mays, and to screen out characteristic volatile components. Methods Low field-nuclear magnetic resonance (LF-NMR) and gas chromatography-ion mobility spectrometry (GC-IMS) technology were used to study the changes in micro moisture, volatile component composition, and relative content of Zea mays under controlled temperature and humidity conditions. Results With the extension of storage time, moisture, fatty acid value, starch, and alcohol soluble protein indicators all undergo certain changes. When stored for 30 days, the moisture content reached equilibrium; the maximum value of fatty acid value was 46.11 mgKOH/100 g when stored at 65% RH for 90 days at 30 ℃, and the fatty acid value was still suitable for storage after 120 days; storing at 20 ℃ was beneficial for the accumulation of starch content; alcohol soluble proteins were significantly affected by temperature; under 65% RH conditions, as the storage temperature increased, the bound moisture content gradually decreased, resulting in the transformation of T20 strongly bound water to T21 weakly bound water and T22 strongly bound water to T23 weakly bound water; under 55% RH conditions, as the storage temperature increased, the bound water content gradually decreased, and the changes in the peaks of non flowing water and free water were consistent with those of bound water; the volatile components in the sample were classified as acids (2 types), aldehydes (20 types), ketones (15 types), alcohols (15 types), esters (12 types), furans (2 types), olefins (3 types), and amines (1 type). Conclusion As the storage temperature increases, the ability of Zea mays to retain moisture gradually weakens, while as the humidity increases, its ability to retain moisture increases. The high temperature and high humidity environment promotes the release of volatile components such as aldehydes and alcohols, while ketones and esters decrease. The 3-pentanone, 1-octen-3-one-M, 1-butanol, 3-methyl-D, 1-hexanol-D, isovaleric acid, methyl ester can be used as characteristic volatile components to distinguish mold growth in high moisture Zea mays, providing reference for the identification of mold growth in high moisture Zea mays.

Tetracycline antibiotics are widely used in animal husbandry, and their main ways of entering milk are through environmental exposure and direct ingestion by cows. Tetracyclines accumulate toxicity through the food chain and pose a threat to human health. Molecular imprinting technology can customize high molecular network polymers that specifically bind to tetracyclines, with many advantages such as high selectivity, good mechanical properties, low cost, high temperature and acid-base resistance, and reusability. It plays an important role in the detection of tetracycline residues in milk. The combination of molecular imprinting and solid-phase extraction technology can simplify the pretreatment process, optimize methods, and effectively solve the separation and purification problems caused by the complexity of milk matrix, including four solid-phase extraction and chromatography techniques: Solid-phase extraction, solid-phase microextraction, dispersed solid-phase extraction, magnetic solid-phase extraction, etc. The specific recognition ability based on molecular imprinting technology combined with sensors (including 5 types of sensors: Molecular imprinting electrochemistry, fluorescence, photonic crystal, plasma resonance, and photoelectric sensors) can improve selectivity, stability, and response speed. The operation is simple, especially suitable for rapid screening on site. This article introduced the research progress of the above-mentioned technologies and sensors in detecting tetracycline residues in milk, analyzed and discusses their application effects, and pointed out the future direction of molecular imprinting technology in this field, providing reference for subsequent research and application.

There are many types of pollutants in food, and exposure involves multiple stages such as raw material, processing, transportation, storage, packaging, and sales. With the improvement of people's requirements for the healthy, nutritive and safe condiments, the pollutants in food have received more and more attention. Liquid chromatography-high resolution mass spectrometry (LC-HRMS) combines the separation ability of liquid chromatography with the advantages of high resolution mass spectrometry, such as wide mass range, fast scanning speed, and high sensitivity, making it an important means in the field of food safety analysis. This review summarized the technical characteristics of quadrupole-time of flight mass spectrometry and quadrupole-orbitrap mass spectrometry, as well as the research progress in the detection of pollutants in food using LC-HRMS technology over the past 5 years. The article focused on the application of LC-HRMS in the targeted and non-targeted determination of pesticides residues, veterinary drugs and their metabolites, food additives, illegal additives and mycotoxins, and prospected the development trend. Aiming to provide reference for the detection of pollutants in food in the future.

Objective To establish a method for simultaneous determination of 13 kinds of illegally added azo industrial dyes (Sudan red I, Sudan red II, Sudan red III, Sudan red IV, Sudan red B, rhodamine B, Sudan red G, Sudan red 7B, para red, Sudan orange G, basic orange 2, basic orange 21, and basic orange 22) in spices using ultra performance liquid chromatography tandem mass spectrometry. Methods After the sample was soaked with water, it was extracted with acidified acetonitrile (containing 1% acetic acid) by ultrasonic extraction, and purified with anhydrous magnesium sulfate and sodium chloride. After concentration, acetonitrile-0.10% formic acid aqueous solution was used as mobile phase, gradient elution, C₁₈ chromatographic column (2.1 mm×150 mm, 1.7 µm) separation, electrospray multi reaction monitoring and positive ion mode determination were used to qualitatively determine 13 kinds of azo industrial dyes in spices, and external standard method was used for quantitative determination. Results The 13 kinds of azo industrial dyes showed good linear relationships within the mass concentration ranges of 0.5-50.0, 1-50, or 4-100 ng/mL, with correlation coefficients (r²) all greater than 0.99; the limits of detection could reach 1.0-10.0 µg/kg, and the limits of quantification could reach 3.0-30.0 µg/kg. The average spiked recovery rates at 1-fold, 2-fold, and 10 fold concentration levels were 75.7% to 102.4%, with relative standard deviations below 10% (n=6). Conclusion This method has the advantages of simple pretreatment, rapid, accurate, and sensitive, and is suitable for rapid screening and quantitative detection of 13 kinds of azo industrial dyes in spices, in order to provide strong technical support for the supervision of illegal addition of azo industrial dyes.

Objective To obtain a comparative analysis of the unqualified infant and toddler foods in the sampling inspection of national food safety supervision from 2018 to 2023. Methods The information of unqualified infant and toddler food samples sampled by the national food safety supervision from 2018 to 2023 was summarized and analyzed from the sampling quantity and product brands, unqualified rate, food categories, unqualified items and sampled areas. Results The total amount of sampling of infant and toddler food decreased in the past 4 years. The unqualified rate decreased from 0.20% (2018) to 0.02% (2022), however, the unqualified rate increased significantly since 2022. Domestic and foreign brands of infant and toddler food had certain risk of problems. Milk powder and rice flour were the main unqualified infant food categories, accounting for 30.30% and 23.23% respectively. In the unqualified items, mineral content accounted for the highest proportion, followed by vitamin content. The source of unqualified infant food was mostly concentrated in the eastern coastal areas of China, and the unqualified rate of online shop sampling was also quite high. Conclusion In recent years, the state's supervision of infant and toddler food has achieved remarkable results, but it still needs to be strengthened, while the frequency and quantity of sampling inspection should be reasonably arranged. The content of mineral and vitamin in infant food doesn't meet standards, which is an urgent problem to be solved. National market supervision departments need to strengthen follow-up supervision.

Objective To prepare a polydopamine (PDA)-based lateral flow immunochromatography assay for the highly sensitive detection of deoxynivalenol (DON) in cereals. Methods In this paper, PDA was synthesized by dopamine self-oxidative polymerization, and the PDA labeled monoclonal antibody (PDA-mAb) probe was prepared by a one-step conjugation method. Subsequently, the PDA lateral flow immunochromatography assay was established using DON antigen as the test line (T line) and goat anti-mouse antibody as the control line (C line). Results The results showed that the cut-off value of the PDA lateral flow immunochromatography assay for detecting DON was 6.0 ng/mL, the visual limit of detection was 0.9 ng/mL, half maximal inhibitory concentration was 1.13 ng/mL, which were 0.88 times and 3.08 times higher than those of fluorescent microsphere test strip and colloidal gold test strip, respectively. Meanwhile, the PDA lateral flow immunochromatography assay possessed well stability and specificity. In addition, the proposed lateral flow immunochromatography assay has been successfully used for the detection of DON in corn, millet, and oats samples, with minimum detection limits of 8.40, 6.87, and 9.89 μg/kg, recoveries ranging from 80.10%-122.05%, and relative standard deviations less than 12.01%. Conclusion In summary, the PDA lateral flow immunochromatography assay established in this work is sensitive, accurate, rapid and simple, and provides technical support for the detection of mycotoxins in cereals.

Edible agricultural products are primary products derived from agriculture, forestry, livestock husbandry and fishery, which are important components of people's daily diet. The widespread use of pesticides in recent years has effectively promoted agricultural development, but the problem of pesticide residue pollution caused by illegal use of banned or restricted pesticides and unscientific pesticide application has attracted considerable attention to the safety of edible agricultural products. As an agricultural powerhouse, China has a fairly comprehensive range of pesticides, and new pesticides are constantly emerging. Therefore, effective regulation of pesticide residues in edible agricultural products, as well as exploration of more convenient, quick, efficient, and sensitive detection methods, has become an important research topic for the inspection and testing industry. This paper briefly summarized pesticide residues in edible agricultural products, focused on the relevant technical methods of pesticide residues detection in edible agricultural products, and looked forward to new detection technologies and methods, in order to provide references for improving the detection of pesticide residues in edible agricultural products, and ensure food safety and people's health.