Objective To establish the qualitative and quantitative methods for water soluble sugars in Cyperus esculentus meal, and to analyze the effects of producing areas and climatic conditions on the kinds and content of sugars in Cyperus esculentus meal. Methods High performance liquid chromatography equipped with a refractive index detector was performed to analyze maltose, raffinose, sucrose, D-glucose, D-galactose, and D-fructose in Cyperus esculentus meal. Aminex^® HPX-87C (300 mm×7.8 mm) sugar-analyzing column was used with a column temperature of 85 °C and a mobile phase of pure water at a flow rate of 0.3 mL/min. The D-galactouronic acid in Cyperus esculentus meal was analyzed with high performance liquid chromatography equipped with an evaporative light scattering detector. XBridge^® Amide 3.5 μm amino column was used with the column temperature of 40 °C. The mobile phase of 0.2% triethylamine water-acetonitrile (20:80, V:V) was used with the flow rate of 0.6 mL/min, and the gas pressure was 40 psi, drift tube temperature was 82 ℃ and the gain of 800. Results An analytical method for 7 kinds of water-soluble sugars in soybean oil was established, which had good accuracy and precision. The limits of detection of the 7 kinds of water soluble sugars were 0.02-0.05 μg and the limits of quantification were 0.06-0.10 μg. The content of 7 kinds of water-soluble sugars, including maltose, raffinose, sucrose, D-glucose, D-galactose, D-fructose, and D-galactouronic acid in 186 samples from 11 Provinces and regions were analyzed based on the method. The total sugar content in the Cyperus esculentus meal samples ranged from 11.10% to 25.51%, with significant differences among different regions. Samples from Northeast, North, and Northwest of China were higher than those from Southern China. The water soluble sugars in Cyperus esculentus meal were mainly sucrose, accounting for 65.48% to 75.85% of total sugar. In addition, maltose, raffinose, and D-galactouronic acid had high content, ranging from 1.01%-2.93%, 0.37%-1.09%, and 1.94%-2.53%, respectively, accounting for 9.11%-12.73%, 1.62%-6.37%, and 7.95%-17.75% of the total sugar content. The content of D-glucose and D-fructose was 0.01%-1.07% and 0.02%-0.78%, respectively, accounting for 0.07%-4.21% and 0.17%-3.28% of the total sugar content, respectively. Except for the samples from Heilongjiang Province, a few amount of D-galactose was also detected in most of other samples. Conclusion This study establish an analysis method for sugar content in Cyperus esculentus meal and investigated the content of water soluble sugars in samples from different producing areas. This provides a basis for breeding and planting research of Cyperus esculentus, and also can offer the guideline to the deep processing of Cyperus esculentus and the preparation and application of carbohydrates.

Objective To establish ultra performance liquid chromatography-tandem quadrupole electrostatic field orbital trap mass spectrometry (UPLC-Q-Orbitrap) and use various data analysis methods to quickly identify the chemical composition of Liubao tea. Methods A Thermo Scientific Hypersil GOLD aQ (2.1 mm×100 mm, 1.9 μm) counm was used with 0.1% formic acid-acetonitrile solution (A) and 0.1% formic acid-water solution (B) as the mobile phase in a gradient elution mode. Detection of chemical components in Liubao tea by positive and negative ion mode of electrostatic spray ion source combined with electrostatic field orbital trap detector. Based on accurate mass to charge ratio data from primary high-resolution mass spectrometry, fragment ions from secondary high-resolution mass spectrometry, Thermo Scientific mzCloud network database, Thermo Scientific high-resolution mass spectrometry database for traditional Chinese medicine components, and relevant literature reports, identify the chemical components. Results Rapid analysis was conducted on the chemical components of Liubao tea, and a total of 36 kinds of compounds were identified, included 3 kinds of amino acid compounds, 3 kinds of phenolic compounds, 16 kinds of flavonoids, 1 kinds of lignin compound, 4 kinds of alkaloids, 1 kinds of terpenoid compound, 2 kinds of coumarins, 4 kinds of organic acid compounds, and 2 kinds of other compounds. Conclusion This study apply UPLC-Q-Orbitrap database to analyze the composition of Liubao tea, which can provide scientific basis for further study on the efficacy and flavor substance basis of Liubao tea.

Objective To establish a method for the determination of nitrite content in pickles by nitroso derivative ultra performance liquid chromatography. Methods A novel and sensitive method for the determination of nitrite content was developed. This is a nitroso derivative produced based on the interaction between nitrite and antipyrine This derivative has strong absorption in 0.02 mol/L acetate buffer solution (contains 0.1% acetic acid) at a wavelength of 345 nm the nitrite content was determined by ultra performance liquid chromatography. Results Nitrite in the linear concentration range of 0.05-5.00 mg/L was determined with a limit of detection 0.01 µg/mL. The high, medium and low concentrations were spiked. The extraction recoveries ranged from 88%-96% (n=6). The relative standard deviation was the precision ranged from 2.0%-4.5%. Conclusion The method can effectively eliminate the interference of chloride ions and other anions and pigments on this experiment. The established analytical method has good sensitivity, accuracy, precision and recovery rate, and is suitable for the detection of nitrite in pickles.

Objective To establish a rapid colloidal gold card method for the determination of fumonisin and T-2/HT-2 toxin in Triticum aestivum L. and Zea mays. Methods The limit of detection, limit of quantitative, precision and accuracy of the method were evaluated in 6 laboratories. Results The limits of detection of fumonisin and T-2/HT-2 toxin methods were 150 μg/kg and 5 μg/kg, respectively. The limits of quantitation were 450 μg/kg and 11 μg/kg, respectively. When the fumonin content in Triticum aestivum L. and corn ranged from 426.39 to 3897.22 μg/kg, the relationship between the method repeatability standard deviation S_r and reproducibility standard deviation S_R and fumonin content was obtained, namely, repeatability standard deviation S_r=1.478m^0.600 and reproducibility standard deviation S_R=4.269m^0.591. When the T-2/HT-2 toxin content in Triticum aestivum L. and Zea mays ranged from 426.39 to 3897.22 μg/kg, the relation between repeatability standard deviation S_r and reproducibility standard deviation S_R and T-2/HT-2 toxin content m was as follows: Repeatability standard deviation S_r=3.1901m^0.218, reproducibility standard deviation S_R=0.2507m^0.492 (Triticum aestivum L. matrix). Repeatability standard deviation S_r=0.8357m^0.333, reproducibility standard deviation S_R=1.1231m^0.585 (Zea mays matrix). The recoveries of fumonisin and T-2/HT-2 toxin ranged from 95.42% to 101.90% and 83.30% to 118.20% respectively. There was no significant difference between the paired t test and the standard method. Conclusion The method has good accuracy and can be widely used for rapid and quantitative determination of fumonisin and T-2/HT-2 toxin in Triticum aestivum L. and Zea mays.

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.

Objective To characterize the composition of amino acids in fish dishes consumed by Liaoning Province residents and to evaluate their nutritional value. Methods The 7 kinds of representative fish dishes for daily consumption were selected, the amino acid composition and content of fish dishes were determined by conventional acid hydrolysis and alkaline hydrolysis methods using a fully automated amino acid analyzer, the amino acid score and amino acid ratio coefficient methods were used to evaluate the comprehensive nutritional value and to analyze the content of essential amino acids in a clustered heat map. Results The 7 kinds of fish dishes had complete amino acid types, with a total amino acid content ranged from 92.88 to 190.00 mg/g; the essential amino acid content ranged from 36.09 to 74.14 mg/g; the ratio of the essential amino acid to the total amino acid ranged from 0.39 to 0.41; and the total content range of sweet amino acids and umami amino acids ranged from 51.23 to 103.37 mg/g. The evaluation of amino acid scores and ratio coefficients showed that the composition of essential amino acids in the 7 kinds of fish dishes was balanced and abundant. The clustering heat map divided the 7 kinds of fish dishes into two categories according to the content of essential amino acids. Conclusion Although there is variability in the amino acid content and nutritional value of fish dishes consumed daily by Liaoning residents, they all contain a wide variety of amino acids with high nutritional value. They can be used as high-quality protein sources. This study can provide a scientific value for the nutritional value analysis of finished dishes.

Objective To establish a method for determination the content and migration of metal elements (lead, arsenic, aluminum) in paper straws by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical spectrometry (ICP-OES), and analyze the changes in the content and migration of 3 kinds of elements. Methods Microwave digestion and immersion in 4% acetic acid for 2 hours were used as pre-treatment conditions. The instrument was analyzed according to the selected working conditions, and a standard working curve was drawn. Three elements were subjected to spiked recovery experiments, and the recovery rate and precision were calculated. Then, the content and migration amount of 3 kinds of elements were detected in 45 samples. Results The linear range of lead and arsenic elements in the ICP-MS method was 5-50 μg/L, with correlation coefficients greater than 0.999 and limits of detection of 0.005 and 0.002 mg/kg. The spiked recovery rates were 96.1% and 104.2%, with relative standard deviations of 1.5% and 3.6%. The linear range of aluminum element in ICP-OES method was 0.5-4.0 mg/L, with a correlation coefficient greater than 0.999 and the limits of detection of 0.3 mg/kg. The spiked recovery rate was 94.0%, with a relative standard deviation of 0.2%. The aluminum content and migration amount in paper straws were relatively high, especially the aluminum content, with an average content of 148.00 mg/kg and a maximum content of 1005.00 mg/kg. The 40% of the straws had a content exceeding 100.00 mg/kg. Conclusion Based on the characteristics of lead, arsenic, and aluminum content in paper straws, this study establishes an analytical method for testing aluminum, lead, and arsenic in paper straws. Based on this method, the content and migration patterns of lead, arsenic and aluminum elements in actual use are explored, providing technical support for a deeper understanding of the safety of paper straws.

Objective To establish a method for the analysis of 19 kinds of metal elements in Nelumbo nucifere Gaertn. by inductively coupled plasma-mass spectrometry (ICP-MS), and to compare and analyze the metal elements content from different areas. Methods The Nelumbo nucifere Gaertn. sample was digested by microwave, and the metal elements content was determined by ICP-MS. The metal element fingerprint was drawn, and principal component analysis was performed on the metal element content using SPSS 26.0 software. Results The fingerprint of 19 kinds of metal elements in the Nelumbo nucifere Gaertn. had certain characteristics, and the content of harmful metal elements should be of concerned. Principal component analysis identified 8 main factors and identified B, S, Ca, Mn, Fe, Zn, Sr, Sb, Ba, As, and Pb as characteristic metal elements for Nelumbo nucifere Gaertn.. The correlation of 19 kinds of metal elements with the comprehensive score value of principal component analysis that were positively correlated in decreasing order were as follows: Pb, As, Ba, Zn, Sb, Mg, Cd, K, S, B, Na, Hg, Cu, Fe, Ni, and negatively correlated correlated in decreasing order were as follows: Sr, Mn, Ca, Mo. Conclusion The method is rapid, accurate and sensitive, and can be used for the simultaneous determination of the content of various metal elements in Nelumbo nucifere Gaertn.. It provides the basis for the quality control and safety evaluation of Nelumbo nucifere Gaertn..