Objective To investigate the Effects of lactic acid bacteria fermentation on the sensory, physicochemical, and flavor quality of sour bamboo shoots. Methods Fresh Dendrocalamus latiflorus bamboo shoots were cut into strips and subjected to fermentation using lactic acid bacteria or natural fermentation in pure water as a control. The study investigated changes in total acidity, amino nitrogen, nitrite content, sensory evaluation, and volatile flavor compounds in sour bamboo shoots fermented with lactic acid bacteria compared to natural fermentation. Results After 60 days of fermentation, the total acidity and amino nitrogen content of the lactic acid bacteria-fermented sour bamboo shoots were 19.28 g/kg and 0.506 g/100 g, respectively, significantly higher than those of the naturally fermented sour bamboo shoots (16.14 g/kg and 0.448 g/100 g, respectively). The nitrite content of the lactic acid bacteria-fermented sour bamboo shoots was less than half that of the naturally fermented sample, with both fermentation methods yielding nitrite levels below 2.9 mg/kg. Solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) analysis detected 10 kinds of volatile flavor compounds in the lactic acid bacteria-fermented sour bamboo shoots, compared to 9 in the naturally fermented ones, with p-cresol being the primary flavor compound. The lactic acid bacteria-fermented sour bamboo shoots exhibited a uniform milky-white color, crisp texture, rich aroma and moderate acidity, achieving a sensory evaluation score of 88 points. Conclusion Sour bamboo shoots fermented with lactic acid bacteria have high sensory scores, good quality, and high food safety.

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.

Pyrus spp. are cherished by consumers for their unique taste and flavor, which has led to their widespread cultivation and consumption around the globe. Pesticides, an essential input for Pyrus spp. production, are vital in the prevention and control of pests and diseases; however, they also contribute to the issue of pesticide residues, which has emerged as a significant concern affecting the quality and safety of Pyrus spp. products. This paper briefly described the registered and commonly used pesticides in China's Pyrus spp. production, analyzed the contamination characteristics of pesticide residues in Pyrus spp. both domestically and internationally, discussed recent findings on the dissipation of pesticide residues in Pyrus spp., reviewed principal analysis techniques and recent advancements for their determination, including sample preparations such as solid phase extraction, dispersive solid phase extraction, multi-plug filtration cleanup, and array-thin film micro-extraction, as well as analytical procedures like triple quadrupole mass spectrometry, quadrupole-time-of-flight mass spectrometry, surface-enhanced raman scattering, and immunoassay, and offered current shortcomings and future research recommendations in this field. This review aims to provide valuable references for ongoing studies on pesticide residues in Pyrus spp.

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 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..

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 analyze the characteristics and differences of volatile components in Wuliangye liquor based on non targeted metabonomics technology. Methods The characteristics and differences of volatile components of 5 series of liquor including Wuliangye, Wuliangye alcohol, Wuliangchun, Wuliangtequ and Wuliangtouqu liquor was analyzed by non targeted metabonomics technology. Results A total of 900 kinds of compounds were detected in 5 series of liquor, including 26 kinds of amines, 86 kinds of alcohols, 51 kinds of aromatics, 18 kinds of phenols, 11 kinds of nitrogenous compounds, 11 kinds of sulfur compounds, 3 kinds of halogenated hydrocarbons, 4 kinds of ethers, 47 kinds of aldehydes, 28 kinds of acids, 143 kinds of terpenes, 78 kinds of hydrocarbons, 79 kinds of ketones, 139 kinds of heterocyclic compounds, 172 kinds of esters, and 4 kinds of others. The number and composition of compounds detected in different Wuliangye liquor were different. The number of compounds with significant differences in Wuliangye was significantly higher than that in Wuliangye alcohol, Wuliangchun, Wuliangtequ and Wuliangtouqu. Conclusion The difference of composition and content in different Wuliangye series liquor is an important factor reflecting the quality of liquor. Non targeted metabonomics technology has good application in the analysis and identification of liquor characteristic components, providing reliable data support for scientific differentiation of Wuliangye series liquor.

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.

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.

Objective To study the characterization and antioxidant activity of Maillard reaction products of autolytic peptides from Stichopus japonicus. Methods The autolysis phenomenon of Stichopus japonicus was taken to dissolve their body walls. Further used D-xylose and Stichopus japonicus autolytic peptides for Maillard reaction to modify autolytic peptides, and the physical and chemical properties and antioxidant activity differences of the Maillard reaction products were analyzed. Results The Maillard reaction conditions were as follows: Reaction time 4 h, reaction temperature 120 ℃, mass ratio of Stichopus japonicus autolytic peptides to D-xylose 1:2. After the reaction, the content of free amino group decreased from (32.35±1.90) μg/mL to (12.68±1.10) μg/mL. The maximum fluorescence emission peak of the Maillard reaction products shifted from 401 nm to 434 nm, and an absorption peak appeared at 288 nm in the ultraviolet absorption spectrum. The molecular weight measurement showed that the large molecular weight material above 3600 u increased significantly. The appearance of the Maillard reaction products from the autolytic peptides of Stichopus japonicus and D-xylose was verified. When the mass concentration of Maillard reaction products was 8 mg/mL, the scavenging ability of hydroxyl free radical, 1,1-diphenyl-2-picrylhydrazine (DPPH) free radical and 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) cation free radical were above 85%, and the reducing ability of Fe³⁺ was 6.3 times higher than that of autolytic peptides from Stichopus japonicus before the reaction. Conclusion The results provide a new reference for utilizing the autolysis of Stichopus japonicus and improving the antioxidant activity of the Stichopus japonicus autolytic peptides.