Carbamate pesticides are synthesized by substituting amino group onto the carbonyl group of carbamic acid derivatives, and are widely used in agriculture because of their short environmental persistence and low residue accumulation. However, due to unreasonable use, the residues of such pesticides and their metabolites in agricultural products far exceed the national standard limits. Long-term consumption of food containing carbamate pesticide residues will induce nervous system diseases, along with carcinogenic, teratogenic and mutagenic effects on the human body, and lead to death in serious cases. Therefore, it is very important to monitor the residues of carbamate pesticides and their metabolites in agricultural products in real time to ensure food safety. This paper summarized and analyzed the commonly used pre-treatment technologies and detection methods of carbamate pesticides in agricultural products, introduced the characteristics of different pre-treatment technologies such as liquid-liquid extraction, solid-phase extraction and QuEChERS method for the extraction of these pesticides, and introduced the detection methods of enzyme inhibition assays and instrument analysis method respectively. The application characteristics of different detection methods for pesticide residues were analyzed, and new detection technologies and methods were prospeced, in order to provide references for the detection and safety supervision of carbamate pesticide residues in agricultural products, so as to ensure food safety and public health.

Objective To investigate the differences in mineral element content between sole fish and basa fish and establish an authenticity identification method. Methods Inductively coupled plasma mass spectrometry were employed to determine 25 kinds of mineral elements in 29 sole fish samples and 24 basa fish samples. Principal component analysis were performed using SPSS 25.0 software on the measurement results, and comparative analysis were conducted on mineral element contents among 3 kinds of different genera of sole fish. Results The total mineral element content in sole fish were significantly higher than that in basa fish. Na, K and Ca were identified as the primary mineral elements in both species, with Sr, As, Mn, Fe and Zn serving as secondary elements. Notably, Sr, As, Mn and Fe were detected exclusively in sole fish but absent in basa fish. Significant differences were observed in 9 kinds of elements: Mg, Ti, Zn, As, K, Ca, Na, Mn, and Fe. Principal components of sole fish within the same genus exhibited relative clustering, with marked differences in 7 kinds of elements: V, Mn, B, Ba, Fe, As and Sr. Conclusion Mineral element analysis can effectively distinguish sole fish from basa fish for authenticity verification.

Objective To construct a novel fluorescent aptamer sensor based on MXene nanomaterials by combining X-type DNA with aptamers for the simultaneous detection of Pb²⁺ and Cd²⁺ in food. Methods X-type DNA structures were prepared by complementary base pairing, and in the presence of Pb²⁺ and Cd²⁺, the aptamer within the X-type DNA structure specifically bound to the target ions and triggers desorption from the MXene surface, thereby restoring the fluorescent signal. Results Under the optimal experimental conditions, the fluorescence signal intensity was linearly correlated with Pb²⁺ and Cd²⁺ in the range of 0.5-500.0 nmol/L, with the limits of detection were 0.33 nmol/L and 0.28 nmol/L, respectively, and the results showed that the sensor had good working performance. Conclusion The fluorescent biosensor prepared in this study has been successfully applied to the spiked analysis of tap water and cornmeal with good recoveries, indicating that it can be used as an effective tool for the detection of Pb²⁺ and Cd²⁺ in food.

Food safety issues induced by pesticide residues pose multiple threats to public health, ecological balance and international trade. In this context, the development of novel analytical technologies featuring rapid response, high sensitivity and on-site applicability has become an urgent requirement in food safety detection. Electrochemical biosensors have demonstrated significant potential in pesticide residue detection due to their unique analytical advantages. Particularly, high performance sensing interfaces constructed with nanomaterials show remarkable improvements in sensor sensitivity, selectivity and stability through their high specific surface area, excellent catalytic activity, and superior electrical conductivity. This paper reviewed the working principle of electrochemical biosensors, focused on discussing the application of nanomaterials in constructing different types of electrochemical biosensors for pesticide residue detection, and looked forward to the future technological development, providing theoretical support and research directions for building a precise and efficient pesticide residue detection system.

Objective To establish a method for the determination of 9 kinds of organic acids (oxalic acid, tartaric acid, quinic acid, malic acid, lactic acid, citric acid, fumaric acid, succinic acid and gallic acid) in fruits and vegetable crisps by liquid chromatography-high resolution mass spectrometry (LC-HRMS). Methods The samples were cleaned up by a SAX solid-phase extraction column. The samples were eluted with 0.1% formic acid in water and methanol as mobile phases and separated on an Eclipse Plus C₁₈ column (4.6 mm×250 mm, 5 μm), and monitored in electron spray ionization (ESI)- mode and quantified by external standard method. Results The calibration curves for 9 kinds of organic acids showed good linearity in the concentration range of 50-5000 ng/mL. The correlation coefficients (r) were all greater than 0.9991, the limits of detection (LODs) were in the range of 1-10 ng/mL, the limits of quantitation (LOQs) were in the range of 10-50 ng/mL, the spiked recoveries were in the range of 96%-98%, and the relative standard deviations (RSDs) were in the range of 1.5%-4.9%. Among them, lactic acid [(16.16±0.30) mg/g] and citric acid [(15.53±0.11) mg/g] were the main organic acids in the fruit and vegetable crisps, and their content was significantly higher than those of other organic acids. In contrast, tartaric acid [(1.29±0.11) mg/g] and oxalic acid [(1.56±0.25) mg/g] were found at lower levels. Conclusion The method is simple, rapid, and accurate and can be used for the qualitative and quantitative determination of organic acids (oxalic acid, tartaric acid, quinic acid, malic acid, lactic acid, citric acid, fumaric acid, succinic acid and gallic acid) in fruit and vegetable crumbles as well as other food.

Objective To develop an ultra performance liquid chromatography-tandem mass spectrometry method for the determination of Nisin residues in various foods. Methods The samples were extracted with 0.1% formic acid solution+acetonitrile (80:20, V:V), delipid with n-hexane, eluted with 0.1% formic acid solution and acetonitrile as mobile phase gradient, and separated by ZORBAX Eclipse Plus C₁₈ (100 mm×2.1 mm, 1.8 μm). Electrospray ion source and positive ion multi-reaction monitoring mode were used for detection, and matrix matching standard curve external standard method was used for quantification. Results The linear relationship between Nisin A and Nisin Z was good in the range of 0.5 to 50.0 μg/mL, and the correlation coefficient was greater than 0.995. The limits of detection and quantitation were 0.05 to 0.30 mg/kg and 0.15 to 1.00 mg/kg, respectively. The recoveries ranged from 88.8% to 106.2% and the relative standard deviations were 1.32% to 8.85% at the 3 added levels of 1.0, 5.0 and 200.0 mg/kg. Conclusion The established method is fast, efficient, repeatable, sensitive and accurate, and can be used for the determination of Nisin A and Nisin Z in batch food samples.

Objective To optimize the processing technology of red glutinous sorghum cookies by response surface methodology. Methods Based on single-factor experiments, the sensory score of red glutinous sorghum cookies was taken as the response value, and the process of red glutinous sorghum cookies was optimized by response surface methodology. Results Based on the basic ratio of total flour 500 g, with other ingredients accounting for the proportion of total flour as butter 75.6%, powdered sugar 37.8%, milk 5.5%, and whole egg liquid 16.8%, and using a 12-tooth piping tip for shaping, the optimal process was that the proportion of red glutinous sorghum flour in the total flour was 53%, the baking time was 24 min, and the baking temperature was 158 ℃. Through verification, the cookies made under these conditions had a complete shape, an attractive color, a crispy texture, and the best sensory quality. Conclusion This process is stable and reliable for processing glutinous sorghum cookies, and the research results can provide theoretical support for the processing of glutinous sorghum cookies.

Objective To analyze the quality characteristics of Ripe Pu-erh tea from Pu'er City. Methods A total of 43 local fermented Ripe tea samples were collected from Pu'er City, and the quality characteristics of this batch of products were systematically analyzed by sensory evaluation combined with biochemical component detection. Results The color dry tea leaves were brown or reddish brown; the infusion were brown red or reddish brown; the aroma were mellow aged fragrance; the taste had typical pure characteristics of stale aroma; the infused leaves were reddish-brown and soft. Biochemical detection data showed that the content of tea sample water extract, tea polyphenols, free amino acids, soluble sugar and theabrownin in these tea samples were 38.7%-51.5%, 4.55%-11.16%, 1.56%-2.89%, 3.49%-8.27% and 6.84%-12.82%, respectively. The total content of catechins and flavonols were 6.76-18.23 mg/g and 0.18-1.90 mg/g, respectively. The content of theophylline and caffeine were 0.01-0.12 mg/g and 15.21-27.31 mg/g, respectively. The content of gallic acid was 1.22-6.56 mg/g. Conclusion Compared with the Ripe Pu-erh tea from other regions, Pu'er City-fermented tea samples demonstrates significantly higher levels of water extract, soluble sugars and free amino acids, coupled with relatively lower caffeine content. This distinctive biochemical composition corresponds to their sensory profile characterized by a thick mellow taste, pronounced sweetness, and reduces bitterness in the tea infusion. The study systematically delineates the sensory quality attributes and biochemical reference ranges of Ripe Pu-erh tea fermented in Pu'er City, providing scientific data support for future cross-regional comparative studies on the quality characteristics of Pu-erh tea.

Objective To establish a method for simultaneous determination of 23 kinds of per-and polyfluoroalkyl substances (PFASs) in food by high efficiency reinforced fat removal bilayer column-ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods The sample was extracted and centrifuged, high efficiency reinforced fat removal bilayer column method was adopted for the purification, the sample solution was separated on an Shim-pack GISS Hp 3 μm C₁₈ column using 2 mmol/L ammonium formate and methanol as mobile phase for gradient elution, detected by tandem mass spectrometry with multiple reactions monitoring (MRM), and quantified by internal standard method. Results The 23 kinds of target compounds of PFASs were well retained on the chromatographic column with good linearity in the range of 0.2-50.0 µg/L (r²>0.995). The limits of detection (LODs) and the limits of quantitation (LOQs) about perfluorobutanoic acid (PFBA) and perfluoropentanoic acid (PFPeA) were 0.06 μg/kg and 0.18 μg/kg respectively. LODs and LOQs about the remaining 21 kinds of perfluorinated compounds were 0.03 μg/kg and 0.09 μg/kg, respectively. The recoveries of the 23 kinds of target compounds of 2.0 μg/kg and 10.0 μg/kg spiked levels in the meat, fish and milk matrix ranged from 70.3%-120.0% with relative standard deviations of 1.56%-9.65%. Conclusion This method is easy, fast, accurate and sensitive, which is suitable for the determination of 23 kinds of PFASs in food.

Objective To establish a method for simultaneous determination of 50 kinds of antibiotics in dried sea cucumbers by multifunctional purification column combined with ultra performance liquid chromatography-tandem mass spectrometry. Methods The sample was extracted with 50% acetonitrile aqueous solution. After purification by multifunctional purification column, 50 kinds of antibiotics were separated using Waters ACQUITY UPLC HSS T3 (100 mm×2.1 mm, 1.8 μm) column with acetonitrile and 0.1% formic acid aqueous solution (include 5mmol/L ammonium acetate) for gradient elution. The mass spectrum was performed by electrospray positive ion mode scanning and multi-reaction monitoring acquisition, and quantified by external standard method. Results The results showed that 50 kinds of antibiotics exhibited good linearity in the range of 0.1-100.0 ng/mL, and the correlation coefficients were all greater than 0.99. The limit of detection ofthe method was 0.1-2.0 µg/kg, the limit of quantitation was 0.5-5.0 μg/kg. Recovery tests were carried out at 3 levels (1 times, 2 times, 10 times of the limit of quantitation) in the blank matrix, the average recoveries of the limit of detection were in the range of 54.83%-120.01%, and all the relative standard deviations (n=6) were 0.08%-9.15%. Conclusion This method has the technical advantages of simple operation process, excellent detection sensitivity, reliable precision, and good reproducibility, it can be applied to rapid screening and qualitative and quantitative detection of multiple antibiotics in dried sea cucumbers.