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.

Objective To investigate the effects of different brewing conditions on the antioxidant activities and effective components of Taraxacum mongolicum tea soup. Methods The method used a controlled univariate design to study the extraction content of total flavonoids, total polyphenols, total polysaccharides, and total amino acids in dandelion tea under different brewing times, temperatures, tea water ratios, and water quality conditions by ultraviolet-visible spectrophotometry. The antioxidant activities of dandelion tea soup were explored using 2,2-diazine-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) cationic radical, 1,1-diphenyl-2- picrylhydrazyl (DPPH) radical and nitroso scavenging rate, and ferric ion reducing antioxidant power (FRAP) as indicators. The relationships between its antioxidant activities and the content of total flavonoids, total polyphenols, total polysaccharides, and total amino acids in the dandelion tea soup were analyzed. Results When the brewing time was 5 min, the nitroso scavenging activity was the best, expressed as the equivalent concentration of vitamin C (VC) per gram of sample was 0.3938 mg VC/g, which was significantly correlated with the contents of total polyphenols, theanines, and glutamic acids, with correlation coefficients of 0.597, 0.598 and 0.616, respectively; When the brewing temperature was 94 ℃, the iron ion reduction capacity was the strongest, at 0.1784 mg VC/g, significantly correlated with the total polysaccharide content, with a correlation coefficient of 0.529; when the tea water ratio was 1:50 (g:mL), the DPPH radical scavenging activity was the strongest, at 0.2571 mg VC/g, significantly correlated with the contents of total theanines and glutamic acids, with correlation coefficients of 0.483 and 0.497, respectively; when the brewing water was tap water, the ABTS cationic radical scavenging activity was the strongest, at 0.2072 mg VC/g, significantly correlated with the total flavonoids and total polyphenols content, with correlation coefficients of 0.417 and 0.787, respectively. In summary, different brewing conditions affected the antioxidant activities and effective components of dandelion. The antioxidant activities of Taraxacum mongolicum tea were the results of the combined effects of various active compounds, including flavonoids, polyphenols, polysaccharides and amino acids. Conclusion To ensure the optimal antioxidant effects of Taraxacum mongolicum tea, when primarily considering antioxidant activities, it is recommended that the best brewing conditions are: A brewing time of 5 min, a brewing temperature of 94 ℃, a tea-to-water ratio of 1:50 (g:mL), and using tap water for brewing.

Objective To detect and analyze the content of As, Cd, Cr, Cu, Ni and Pb in different dried Lycium barbarum L. from Nuomuhong Farm, Chaidamu, and evaluate the health risk of heavy metals in Lycium barbarum L. via the dietary route to humans. Methods The content of 6 kinds of heavy metals in Lycium barbarum L. was determined by inductively coupled plasma emission spectrometer. The pollution degree of Lycium barbarum L. heavy metals was evaluated by single factor index, mean pollution index, pollution factor analysis and Nemero's composite pollution index. The target risk factor method was used to evaluate the health risk of single and complex heavy metal intake of Lycium barbarum L. Results The single pollution index of 6 kinds of heavy metals in Lycium barbarum L. in this area was less than 1, and the comprehensive pollution index was less than 0.7, and the mean pollution index of the lock-in freshness group was less than 0.1, which was uncontaminated, and the mean pollution index of the sun-dried, hot air dried, and hang-dried groups was less than 0.2, which was a slightly contaminated state, and among them, Cu, and Cd were the main contaminating factors. Through correlation and principal component analysis, the sources of heavy metal pollution in the drying process of Lycium barbarum L. were characterized by diversified and multiple pathways, and the heavy metal content of Lycium barbarum L. that had undergone lock-in freshness treatment and hang-dried treatment had a higher safety coefficient; the single or compound heavy metals ingested by the human body through the consumption of Lycium barbarum L. did not pose a health risk to either children or adults. Conclusion The pollution degree of heavy metal of Lycium barbarum L. in this region is low, and the content is in accordance with the limited requirement of Chinese Pharmacopoeia 2020, and there is a certain effect of different drying on the heavy metal content of Lycium barbarum L., and this test can provide a reference basis for the prevention and control of heavy metal pollution of Lycium barbarum L. in the drying system.

Objective To analyze Cyperus esculentus by near infrared spectroscopy, and trace geographical origin of Cyperus esculentus by the identification model in chemometrics. Methods A total of 408 samples of Cyperus esculentus samples from Hebei, Hunan, Shandong, Xinjiang, and Yunnan were analyzed for provenance tracing using near-infrared spectroscopy and chemometric software, 3 kinds of spectral preprocessing methods including multiplicative scatter correction, standard normal variate transformation and standard normal variate transformation & detrending, were used respectively, and 5 kinds of recognition modes such as support vector machine (SVM), soft independent modeling of class analogy (SIMCA), orthogonal partial least squares discriminant analysis (OPLS-DA), partial least squares discriminant analysis (PLS-DA), and K-nearest neighbor algorithm (KNN) were used to identify the geographical origin. Results The modeling recognition rates of the 5 kinds of modes including SVM, SIMCA, OPLS-DA, PLS-DA, and KNN were 91.89%, 94.47%, 62.37%, 65.32%, and 100.00% respectively. The KNN was selected as the origin identification model, and the impact of different preprocessing methods, data preprocessing and sample distance on the stability of the model prediction results were analyzed in order to select the optimal model parameters. The prediction set recognition rate could reach 100.00% by using multiplicative scatter correction spectral preprocessing method, one of data preprocessing methods including UV, Pareto, automatic, or centering, and block distance as the sample distance. Conclusion The technology of near infrared spectroscopy combined with KNN mode has the advantages of fast analysis speed, simple operation, easy sample pretreatment, non-destructive, on-line qualitative and quantitative analysis, etc., and has a certain application prospect.

Objective To develop a method for the simultaneous determination of lutein, zeaxanthin, α-carotene, and β-carotene in infant formula milk powder and natural foods by online solid phase extraction-liquid chromatography (online SPE-LC). Methods Samples were saponified with 50% potassium hydroxide solution at 70 ℃ for 15 min. Saponified solution was diluted with 70% ethanol, and after high-speed centrifugation, the supernatant was directly analyzed. A styrene-divinylbenzene copolymer-based SelectCore PSS-packed chromatographic column was chosen as the online SPE column, using 80% methanol-water as the initial loading solvent and acetonitrile/methyl tert-butyl ether as the washing solvent. A ChromCore C₃₀ column (4.6 mm×250 mm, 3 μm) was used as the analytical column, with acetonitrile-methanol (26:74, V:V, 0.4 g/L of ascorbic acid) and methyl tert-butyl ether as the mobile phase for gradient elution. The flow rate was 1.0 mL/min, and the detection wavelength was 450 nm. Results The 4 target analytes in infant formula milk powder and natural foods were well separated. Linear correlation coefficients for all target analytes were greater than 0.9999. The limit of quantification of method for lutein, zeaxanthin, α-carotene, and β-carotene were 0.77, 0.72, 0.94, and 1.40 μg/100 g, respectively. Average recovery rates of infant formula milk powder were 99.76%, 103.51%, 99.16%, and 97.92%, respectively. The relative standard deviations of method repeatability for all the analytes were less than 2.5%. Conclusion This method is accurate, reliable, and reproducible and can meet the quantitative requirements of lutein, zeaxanthin, and α-carotene, β-carotene in foodstuffs. It can be applied to the determination of real samples.

Objective To explore of odor differences and volatile differences between rape honey-adulterated and syrup-adulterated samples and real honey. Methods Different proportions of 5%, 10%, 20% and 30% syrup-adulterated and rape honey-adulterated samples were constructed, and the electronic nose technique and headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS) were used to analyze the odors and volatiles of the adulterated and authentic honey samples. Results The electronic nose (E-nose) combined with the principal component analysis (PCA) and sparse partial least squares discriminant analysis (sPLS-DA) could distinguish different botanical honey of linden honey, jujube honey acacia honey, and could distinguish syrup-adulterated samples from real honey, but could not distinguish rape honey-adulterated samples from acacia honey. The GC-MS results showed that 62 kinds of volatile compounds were identified in acacia honey, linden honey and jujube honey, with the highest content of alcohols in acacia honey, aldehydes in jujube honey, terpenes in linden honey. The content of volatile compounds in combination with sPLS-DA could distinguish 100% acacia honey, 100% linden honey from 5%-30% syrup-adulterated samples and 5%-30% rape honey-adulterated samples. Conclusion The odor analysis and volatiles analysis based on E-nose and GC-MS combined with chemometrics analysis can be used to identify syrup-adulterated and rape honey-adulterated samples. The results of the study provide a reference for honey traceability and adulteration identification studies.

Objective To explore the effects of harvesting periods on nutritional quality, processing properties and antioxidant activities of different parts of Fagopyrum tataricum. Methods The harvesting period was determined based on the first flowering time, and the flavonoid content, protein content, dietary fiber content, water holding capacity, oil holding capacity and antioxidant activity of seeds, stems, flowers and leaves of Fagopyrum tataricum at different harvest periods were determined measured and analyzed. Results The seeds, stems, leaves, and flowers of Fagopyrum tataricum all include the rich nutrients and the biological activity ingredient, with excellent processing properties. The flavonoid content, protein content, dietary fiber content, water and oil holding capacity of Fagopyrum tataricum seeds showed a downward trend, while the dietary fiber content of Fagopyrum tataricum stems and flowers generally showed an upward trend. The flavonoid and protein content of Fagopyrum tataricum stems and leaves decreased. The dietary fiber content of Fagopyrum tataricum leaves, flavonoid content and total antioxidant activity of Fagopyrum tataricum flowers increased first and then decreased. The total antioxidant capacity and flavonoid content of Fagopyrum tataricum flowers were significantly higher than other parts of tartary buckwheat. The highest total antioxidant capacity and flavonoid content were found 14 days after flowering, at 369.42 μmol/g and 7.83%, respectively, which were 6.2 and 8.8 times that of Fagopyrum tataricum seeds. Conclusion As food processing raw materials, different parts of Fagopyrum tataricum have the potential and value for food development and processing, and can be fully utilized. The nutrition and functional components of different parts of Fagopyrum tataricum are directly affected by harvest period, and the reasonable harvest period shall be determined based on the purpose in production.

Objective To establish a high performance liquid chromatography-ultraviolet detector method for the determination of xylo-oligosaccharide content in food. Methods The sample size, hydrolysis time, derivatization time and purification times in the pre-treatment method were investigated. Gradient elution was compared with isocratic elution to fix the chromatographic conditions. Moreover, the detection wavelength and column temperature were obtained at the same time. Results The optimized condition was as follows: Weighing sample 2.0 g; hydrolysis time 100 min; derivation time 100 min; purification for 3 times; mobile gradient elution was employed, column temperature 30 ℃; detection wavelength 250 nm. Conclusion This method has good accuracy and sensitivity for the determination of xylo-oligosaccharides in food. This study provides data support for the development of a method for the determination of xylo-oligosaccharides in food.

Objective To explore the optimal conditions of different deodorization treatment methods and compare the main flavor components of oyster raw materials, oyster enzymatic hydrolysates and the products obtained through different deodorization methods. Methods Taking the Crassostrea hongkongensis enzymatic hydrolysate as the research object, the changes in flavor after deodorization of the samples were investigated by means of single-factor experiments, sensory analysis and physicochemical analysis in combination. Results The optimal conditions for activated carbon deodorization were reaction time 50 min, reaction temperature 50 °C, and the amount of activated carbon addition was 1.0%. The optimal conditions for yeast deodorization were a fermentation temperature of 40 °C and a fermentation time of 60 min, and the yeast addition amount was 1.0%. Compared with oyster raw materials, the total free amino acid content in the enzymatic hydrolysate increased, both bitter and sweet amino acids increased, while the umami amino acids decreased slightly. Compared with the enzymatic hydrolysate, the sweet amino acids of the product treated with combined deodorization increased slightly, while the bitter and umami amino acids decreased slightly. The relative content of alcohols and acids increased by 21.50%. The relative content of ketones decreased by 8.49%, and the clam flavor and oil flavor decreased. Conclusion The combined deodorization of activated carbon and yeast effectively improves the flavor of Crassostrea hongkongensis enzymatic hydrolysate, providing valuable preliminary data for the development of oyster condiments.

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.