Objective To establish a method for simultaneously determining the migration amounts of 24 kinds of organophosphate esters (OPEs), organophosphite antioxidants (OPAs), and parabens (PBs) in food contact materials by liquid chromatography-tandem mass spectrometry. Methods The food contact materials to be tested were subjected to migration experiments in accordance with the expected types of food and contact modes, so as to obtain the soaking solution. After centrifugation, the soaking solution was separated by liquid chromatography, determined by tandem mass spectrometry, and quantified by matrix-matched standard curve. Results The optimized method could simultaneously detect 24 kinds of OPEs, OPAs, and PBs in the migration soaking solutions of food contact materials. The limits of detection were 0.01-0.58 µg/L and the limits of quantitation were 0.03-2.00 µg/L. The spiked samples recovery rates ranged from 69.0%-129.6%, with relative standard deviations of 0.5% to 10.9% (n=6). The 20 packaging film bags, 10 disposable take-out boxes and 20 paper tableware items were tested. The ΣOPEs ranges were <limit of detection-19.1 μg/L, ΣOPAs were <limit of detection-1248 μg/L, and ΣPBs were <limit of detection-0.501 μg/L. The monitoring of the migration amounts of food contact materials was limited, its health risks required more attention and research. Conclusion This method is simple to operate and highly sensitive, which is suitable for the determination of the migration amounts of OPEs, OPAs and PBs in food contact material samples.

Objective To investigate and analyze the current situation of pesticide residues in tea in Tongzhou District market of Beijing in 2024. Methods This study tested and analyzed 17 kinds of pesticide residues in 262 tea samples by using gas chromatography-tandem mass spectrometry (GC-MS/MS). Results The detection rate of pesticide residues in tea in Tongzhou District was 96.56%. Especially, the detection rate of chlorfenapyr was the highest (89.31%) and bifenthrin was the second (85.11%). Furthermore, two kinds of prohibited pesticides (methyl parathion and methamidophos) and 2 kinds of restricted pesticides (fenvalerate and ethoprophos) were detected. These 4 kinds of harmful pesticides exceeded the maximum residue limits. In addition, the obsolete pesticide hexachlorobenzene was detected in other 5 samples. The analysis of residue characteristics revealed that 75.57% of the samples had 2-5 kinds of compound residues, of which oolong tea had the most residues. There were 6 tea detected to have excessive pesticide residues. The exceedance rate in descending order was white tea (12.20%), oolong tea (10.77%), dark tea (8.11%), green tea (6.52%), yellow tea (5.88%), black tea (1.79%). There was no significant difference in pesticide detection rate among different markets (P>0.05). Conclusion The detection rate of pesticide residues in tea in Beijing Tongzhou market is high, and complex pollution is common, but the overall over-standard rate is low (7.63%). The presence of prohibited and restricted pesticides in some samples highlights the need for stricter source control and routine monitoring by relevant authorities to ensure tea quality and safety.

Objective To explore the antioxidant capacity and enzyme inhibition activity of strong fragrance natural spices. Methods The total phenolic content in spices was determined using the Folin-phenol colorimetric method. The antioxidant activity of spices was studied using the scavenging ability of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) ammonium salt (ABTS) cation radical and total antioxidant activity as indicators. Using polyphenol oxidase (PPO) and peroxidase (POD) activities as indicators, the enzyme inhibitory activity of spices was studied. Results The results showed that there was a difference in the total phenolic content among strong fragrance spices, with the highest content in Eugenia caryophyllata. Among the spices, Syzygium aromaticum, Eugenia caryophyllata, Cinnamomum loureirii, Cinnamomum burmanni and Pimenta dioica exhibited strong DPPH free radical scavenging ability. Syzygium aromaticum, Eugenia caryophyllata and Cinnamomum burmanni had strong ability to scavenge ABTS cation free radicals. The 8 types of spices, including Syzygium aromaticum, Eugenia caryophyllata, Elettaria cardamomum, Cinnamomum loureirii, Artemisia dracunculus, Cinnamomum burmanni, Pimenta dioica and Cinnamomum cassia, had a certain total antioxidant capacity. Cinnamomum cassia had the strongest inhibitory activity on PPO enzyme, while Cinnamomum burmanni had the most significant inhibitory effect on POD enzyme. The total phenolic content in spices was significantly correlated with antioxidant activity and enzyme inhibition activity. The total phenolic content was negatively correlated with the median inhibition concentration (IC₅₀) value of DPPH free radical scavenging ability, ABTS cation radical scavenging ability and inhibition of POD activity, and positively correlated with total antioxidant capacity (P<0.05, P<0.01). Conclusion Eugenia caryophyllata, Syzygium aromaticum, Cinnamomum burmanni, Cinnamomum loureirii and Cinnamomum cassia have antioxidant and enzyme inhibitory activities, and are potential natural antioxidants and browning protectants, which have the prospect of developing into healthy, efficient and economical natural antioxidants, preservatives and color protection agents.

Objective To study the changes of acid value, benzo [a] pyrene, 4 kinds of polycyclic aromatic hydrocarbons (PAH4) and 16 kinds of polycyclic aromatic hydrocarbons (PAH16) content in frying french fries soybean oil/peanut oil at different temperatures and times. Methods The acid value in oils was titrated by anhydrous ether:isopropanol (1:1, V:V) using phenolphthalein as an indicator. The polycyclic aromatic hydrocarbons in samples were saponified by KOH/ethanol, extracted with n-hexane and cleaned-up by solid-phase extraction column, detected by gas chromatography-mass spectrometer. Results With the increase of frying temperature and time, the acid value increased rapidly, and the changes in peanut oil were more sensitive. At the same temperature, both benzo [a] pyrene and PAH4 showed an irregular fluctuating growth with time, and the higher the temperature, the faster the increase. The content of PAH16 rapidly increased with time and temperature, and its changes were more sensitive than those of benzo [a] pyrene and PAH4. Under the same conditions, the increase of benzo [a] pyrene, PAH4 and PAH16 in peanut oil was less than that in soybean oil. Conclusion At the same conditions, PAH16 shows more significant changes compared to benzo [a] pyrene and PAH4, so the limits of PAH16 should be given more attention.

Objective To establish a method for the determination of 9 kinds of pesticide residues in black tea and green tea based on multi-walled carbon nanotubes (MWCNTs) combined with gas chromatography-tandem mass spectrometry (GC-MS/MS). Methods The key parameters were optimized by single factor experiment, including the amount of MWCNTs, ultrasonic extraction time and extraction solvent, and the methodological performance was evaluated, including linear range, detection limit, quantification limit, accuracy and precision. Results The linear relationship of this method was excellent, with correlation coefficients all greater than 0.99. The limits of detection and limits of quantitation were 0.002-0.004 mg/kg and 0.007-0.012 mg/kg, respectively. The recoveries of 9 kinds of pesticides in black tea and green tea were 71.52%-118.80%, and the relative standard deviation were 1.00%-6.92%. Conclusion This study successfully establishes a pesticide residue detection method based on MWCNTs combined with GC-MS/MS, which has the advantages of high sensitivity, high recovery rate and low solvent consumption, and significantly improves the detection efficiency. The actual sample detection shows that this method is suitable for the rapid screening of commercially available tea, and provides reliable technical support for the regulatory authorities.

Objective To investigate the microbial contamination in frozen drinks sold in Taicang City from 2022 to 2024. Methods A total of 118 samples of frozen drinks sold in Taicang City were collected from 2022 to 2024, inspected and judged according to GB 2759—2015 National food safety standard-Frozen drinks and ingredients. Results One sample had an excessive total bacterial count, and 4 samples had an excessive coliform group, with failure rates of 0.85% and 3.39%, respectively; the 72.88% (86/118) of the samples had a measured total bacterial count of greater than or equal 5 CFU/g, and 6.78% (8/118) of the samples had a measured coliform bacterial count of greater than or equal 5 CFU/g; Staphylococcus aureus, Salmonella and Listeria monocytogenes were not detected in the sample. Conclusion From 2022 to 2024, the hygiene quality of frozen drinks sold in Taicang City is relatively good. It is recommended that regulatory authorities continue to conduct hygiene supervision on frozen drinks production enterprises. Enterprises continue to strengthen hygiene management, control production, transportation and storage processes, to ensure the hygiene quality of frozen drinks.

Objective To establish a safety, rapid, cost-effective and reliable analytical method for trace elements detection in aluminum foil based on fiber laser induced breakdown spectroscopy. Methods Using standards to evaluate analytical sensitivity and limit of detection of fiber laser induced breakdown spectroscopy after optimization of laser pulse width, pulse energy, repetition rate and baseline-correction, and the optimized method was applied to analyze trace elements in aluminum foil samples. Results Calibration curves for most elements achieved regression coefficients up to 0.99. Detection sensitivity and limit of detection followed the descending order of Mn>Cr>Cu>Ti>Mg>Fe>Zn>Si, and the average relative error of leave-one-out cross validation of all the elements was 14.45%. The detection results of 8 kinds of trace elements in 27 kinds of aluminum foil samples showed that Fe and Si were frequently detected, while Cu and Ti elements were rarely detected and Cr, Mg, Mn and Zn elements were not detected. Conclusion This method requires no sample preparation, offers rapid analysis speed, and enables simultaneous multi-element detection with high sensitivity, which promisingly makes it a reliable approach for rapid determination of trace elements in aluminum foil.

Pork quality is an economically critical trait in swine production, necessitating rapid and accurate evaluation methods to optimize processing efficiency and ensure trade compliance. Recent advancements in artificial intelligence algorithms and sensor technologies have driven the development of non-destructive detection methods based on artificial intelligence, which are now widely applied in the meat industry. Integrating digital image processing with artificial intelligence learning algorithms and multi-sensor data fusion to achieve automated, real-time monitoring of pork quality throughout processing chains represents a pivotal research direction for ensuring meat safety and quality. This article summarized the current key technologies for non-destructive testing of pork quality, including near-infrared spectroscopy, hyperspectral imaging, Raman spectroscopy, fluorescence spectroscopy, terahertz spectroscopy, electronic nose/tongue technology and computer vision systems, elaborated the principles, characteristics and application status of different technologies, and discussed and forecasted the shortcomings and future development directions of different technologies, aiming to provide reference for the application of non-destructive testing technology in pork quality evaluation.

Objective To establish a qualitative identification model and rapid identification method of local mutton in Henan province by using near infrared spectroscopy and fisher method. Methods A total of 181 mutton samples were selected from 5 local sheep breeds and 1 Huyang breed in Henan Province, and dried powder samples were prepared. Spectral scanning was performed in the wavelength range of 1400-2500 nm, and discrimination models were established through different pretreatment. Results The results showed that the spectral patterns of different breeds of mutton showed the same trend, and the original spectra could be used to identify sheep and goats with an accuracy of 94.0% and 85.0%, respectively. After spectrum processing by smoothing, first-order derivation, multiplicative scatter correction (MSC) and other different methods, the discrimination accuracy was improved, among which the combination of first-order derivation+MSC had the best effect, the discrimination accuracy of 1400-2500 nm wavelength was 100.0%, and the cross-validation rate was 92.8%. When the model was used to identify 6 varieties of mutton, the accuracy of calibration set reached 100.0%, the cross-validation rate was above 87.5%, and the prediction set of 4 varieties reached 100.0%. After wavelength segmentation, the prediction accuracy for the range of 1400-1620 nm was the best, but the accuracy of individual identification decreased; For different discrimination methods, the identification accuracy of sophora goat was all above 95.0%. Conclusion In summary, near infrared spectroscopy technology in the long-wave range of 1400-2500 nm could accurately identify the variety of mutton, of which the first derivative+MSC preconditioning was the best. For the different varieties, the accuracy of sophora goats was the highest.

Objective To investigate the characterization of potential pathogen and antibiotic resistance genes (ARGs) from some commercially raw fruit and vegetables in Beijing, 2024, and explore their potential food safety risks. Methods In this study, the characterization and potential risks of ARGs, mobile genetic elements (MGEs) and potential pathogens were described by the combining high-throughput quantitative polymerase chain reaction (HT-qPCR), 16S rRNA amplicon sequencing with bio-informatics and multivariate analysis. Results A total of 182 ARGs subtypes belonging to 9 antibiotic types and 9 MGEs subtypes were detected with the abundance of 6.08×10³-1.57×10⁸ copies/g and 3.77×10⁴-3.50×10⁸ copies/g, respectively. It was seen that the diversity and abundance of ARGs, MGEs and bacterial community in fruits were significantly lower than those in vegetables (P<0.05). Acinetobacter, Leuconostoc, Klebsiella, Stenotrophomonas and Serratia were the main potential pathogens, with Enterobacterales and Acinetobacter johnsonii as signature potential pathogens in solanaceous and leafy vegetables, respectively. MGEs and multiple ARGs were carried by the most of potential pathogens with multiple antibiotic resistance, whose transmission among them were mainly drove by the horizontal gene transfer of MGEs carrying ARGs (57.56%). Conclusion There are various and abundant ARGs and potential pathogens in raw vegetables and fruits in Beijing, 2024, with multiple antibiotic resistance, whose transmission among bacterium are mainly drove by the horizontal gene transfer of MGEs carrying ARGs, which can threaten human health. High attention shall be attached.