To investigate the sensory characteristics and determine the biochemical components of different grades of Daguan Cuihua tribute tea.

The 5 green tea samples were selected, including flat-shaped tea and 4 grades of golden ear curly tea (special grade I, special grade III, grade I, grade II). Sensory evaluation shall be conducted in accordance with GB/T 23776—2018 Methods for sensory evaluation of tea. The content of water extract,tea polyphenols, free amino acids, catechins, caffeine and flavonoids were determined using the constant weight method,folin-phenol colorimetry, ninhydrin colorimetry and high performance liquid chromatography, respectively.

Golden ear special grade II showed the highest water extract content (49.37%), while golden ear special grade III had the lowest (42.67%). The content of free amino acids (2.34%) and tea polyphenols (32.52%) in flat-shaped tea were both significantly higher than those in other samples, whereas golden ear grade II had the significantly lowest free amino acid content (1.33%). Sensory evaluation results indicated that flat-shaped tea presented a “rich, mellow and refreshing taste with prominent bean fragrance”, golden ear special grade I “tasted fresh, strong and mellow with distinct tender aroma”,and golden ear special grade III “delivered fresh, strong and rich flavor with lasting sweet aftertaste and obvious tender aroma”, while golden ear grade I and II had relatively weaker taste intensity.

Daguan Cuihua tribute tea exhibits excellent sensory evaluation and abundant biochemical components, making it suitable for development as a premium green tea in Yunnan.

To investigate the suitability of 3 kinds of tea plant varieties in Fuliang County for black tea production.

Fuliang black tea was produced using the Group variety, Zhuyeqi and Zhuye variety as raw materials. The sensory quality, biochemical components and flavor compounds of the 3 kinds of Fuliang black teas were systematically compared.

Sensory evaluation indicated that Zhuyeqi exhibited prominent golden tips, a pure red-yellow liquor color and the highest overall score; Zhuye variety produced the brightest liquor color. Physicochemical analysis revealed significantly higher water-soluble substances (43.53%±0.02%), caffeine (43.70mg/g), catechin gallate(0.67%±0.01%) and gallic acid (4.11 mg/g) in Zhuye variety; higher tea polyphenols (8.85%±0.13%) and catechins(0.37%±0.02%) in Group variety; and superior theabrownins (7.23%±0.05%) accumulation in Zhuyeqi. Analysis of the taste activity value (TAV) showed that caffeine was a common key bitter compound, while epigallocatechin and gallic acid contribute to astringency to varying degrees across different varieties. Specifically, epigallocatechin (TAV=1.08)was the key bitter compound in Group variety; epicatechin (TAV=1.15) was the key astringent compound in Zhuyeqi;and catechin gallate (TAV=1.22) was the key astringent compound in Zhuye variety. The aroma components varied significantly. Geraniol was the dominant aromatic component in Group variety (33.09%) and Zhuyeqi (29.91%),imparting rose-like and sweet fragrance notes, whereas Zhuye variety exhibited a balanced profile consisting of β-linalool (25.38%) and geraniol (17.24%).

This study clarifies the differences in sensory quality,characteristic flavors and aroma components among the 3 kinds of varieties, providing experimental basis for variety selection, targeted processing and quality control of Fuliang black tea.

To construct a flavor wheel and systematically characterize the sensory characteristics of Yunnan large-leaf white tea.

Following established international methodologies for flavor wheel development and the national standard GB/T 16861—1997 Sensory analysis-Identification and selection of descriptors for establishing a sensory profile by a multidimensional approach, 22 representative tea samples varying in vintage,origin and cultivar were selected for sensory evaluation. Core sensory descriptors were extracted, screened and refined to develop the Yunnan large-leaf white tea flavor wheel. Furthermore, M and multivariate statistical analysis was employed to identify key differential descriptors.

Finally, a total of 38 descriptive words that represent distinct flavor profiles were determined, comprising 16 aroma terms (e.g., orchid, osmanthus), 7 infusion color terms (e.g., yellowish green, light yellow, deep yellow) and 15 taste/mouthfeel terms (e.g., sweet aftertaste, mellow sweetness, fresh briskness).These descriptors were successfully applied in flavor profiling.

The proposed descriptive system effectively characterizes the flavor profile of Yunnan large-leaf white tea and successfully differentiates samples across categories, validating the scientific robustness of the constructed flavor wheel. This study provides a standardized framework for quality assessment and facilitates communication among producers, consumers and connoisseurs by establishing a shared sensory vocabulary, thereby enhancing the overall appreciation of this tea.

To explore the quality characteristics of Laoshan ancient tree sun-dried green tea in Malipo and analyze the internal correlations among physicochemical indexes, color, electronic sensory properties and artificial sensory evaluation.

The content of water extract, tea polyphenols, free amino acids, caffeine and catechins were determined in the sun-dried green tea water of ancient trees on the Laoshan of Malipo. A colorimeter, electronic nose and electronic tongue were employed to quantitatively characterize the color, aroma and taste of tea infusions,respectively followed by comprehensive analysis combined with artificial sensory evaluation.

The content of water extract, tea polyphenols and catechins in all samples were higher than the national standard GB/T 14456.2—2018 Green tea Part 2: Dayezhong green tea. The absolute values of the coefficients of variation for the polyphenol-amino acid ratio, a^* and sour, astringent, bitter and salty taste indicators all exceeded 30%. Principal component analysis extracted 5 principal components, which could be integrated into 3 core evaluation dimensions (physical and chemical constituents-taste, physical and chemical constituents-tea soup color and volatile aroma) and 2 secondary auxiliary dimensions, enabling effective quality discrimination of tea samples. Significantly positive correlations were found between free amino acids and sweetness, L^* and infusion color score, a^* and astringency as well as b^* and bitterness(P<0.05). Partial least squares regression analysis showed that the response values of b^* and W1C, W1W, W3S,astringency, bitter aftertaste, saltiness and sweetness made significant contributions to the artificial sensory score.

Laoshan ancient tree sun-dried green tea in Malipo exhibits excellent overall quality. The polyphenol-amino acid ratio, a^* as well as sour, astringent, bitter and salty taste indicators are the core factors driving quality differences. Tea quality is synergistically determined by water-soluble taste substances, color and aroma components, and precise quality evaluation can be achieved through principal component analysis.

To establish a method for simultaneous determination of 6 kinds of synthetic sweeteners in tea and tea products by QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry.

Samples were extracted with acetonitrile-water (8:2, V:V), salted out with anhydrous magnesium sulfate and sodium acetate, and purified via dispersive solid-phase extraction using octadecylsilane adsorbent and N-propylethylenediamine adsorbent sorbents. Chromatographic separation was performed on a Waters ACQUITY UPLC HSS T3 column (100 mm×2.1 mm, 1.8 μm) using gradient elution with a water-acetonitrile mobile phase at a flow rate of 0.2 mL/min and an injection volume of 5 μL. The analytes were detected in electrospray negative-ion multiple reaction monitoring mode and quantified by external standard method.

The linear relationship of the 6 kinds of synthetic sweeteners was good within the mass concentration range of 2–1000 μg/kg (r>0.99). The limits of detection were 5–25 μg/kg and the limits of quantitation were 15–75 μg/kg. The average recoveries at 100, 500, 2500 μg/kg spiked levels ranged from 88.34%–103.21%, with relative standard deviations of 0.56%–7.63%.

The proposed method is simple,rapid, sensitive, accurate and reliable, making it well suited for the simultaneous rapid detection of various synthetic sweeteners in tea and tea products.

To investigate the flavor quality characteristics of sun-dried green tea from Mangjing Village, Jingmai Mountain.

Sun-dried green tea samples from different regions were selected as research objects. The quality components of tea samples were detected by biochemical component analysis, electronic nose technology and headspace solid-phase microextraction-gas chromatography-mass spectrometry, and the key aroma components were screened in combination with the relative odor activity value.

The biochemical components of sun-dried green tea from different regions showed certain differences, whereas the overall variation was relatively small. Electronic nose analysis indicated that all samples exhibited the highest response values on the W1S sensor. Although differences in volatile compounds were observed among samples, their overall odor profiles were highly similar. A total of 126 volatile compounds were identified by gas chromatography-mass spectrometry.Among them, linalool, hexanal, nonanal, octanal, heptanal, hexanol, α-ionone, α-terpineol and 1-octen-3-ol were identified as key aroma-active compounds in tea samples from different regions.

Under the same mountain ecological environment, regional differences exert relatively limited effects on the flavor characteristics of sun-dried green tea. This study provides a reference for revealing the regional flavor characteristics of sun-dried green tea from Mangjing Village, Jingmai Mountain.

To optimize the brewing conditions of Zigui Simian tea, and analyze its quality.

By means of single-factor and orthogonal experiments, through sensory evaluation and analysis of the main physical and chemical components, the process optimization of the tea-to-water ratio, water temperature, brewing time and brewing frequency was carried out, and their influences on the quality of Simian tea were analyzed.

The single‑factor brewing experiment results showed that brewing at 80–90  ℃ produced tea infusions with light‑green and bright liquor,tender chestnut‑like aroma, relatively fresh-mellow taste, and tender‑green bright infused leaves. At a tea‑to‑water ratio of 1:40–1:50 (g:mL), the liquor was light‑green and bright with moderately strong tender chestnut‑like aroma and moderately fresh‑mellow taste. The optimal comprehensive sensory quality was obtained with 40–60  s for the first infusion, 40–46  s for the second infusion and 40–80  s for the third infusion. Orthogonal experiments indicated that brewing temperature was the core factor determining the total sensory score, aroma purity and infused‑leaf colour of Simian tea; tea‑to‑water ratio affected liquor brightness and taste freshness‑mellowness. Under the conditions of 80–85  ℃, tea‑to‑water ratio of 1:40–1:50 (g:mL) and brewing duration of 40–60  s, the tea infusion exhibited light‑green bright liquor, prominent tender chestnut‑like aroma and fresh‑mellow taste, and tender‑green bright infused leaves. Quality component analysis demonstrated that tea polyphenol concentration in infusion was most strongly affected by brewing temperature, showing a high positive correlation; other indicators were most influenced by tea‑to‑water ratio, presenting a high negative correlation. Brewing time exerted no significant effect on all indicators(P>0.05).

The optimized brewing conditions in this study can better manifest the colour, aroma and taste qualities of Zigui Simian tea, providing theoretical basis and practical guidance for its scientific brewing.

To compare the characteristics of antioxidant and antimicrobial activities of polyphenol-enriched extracts from 3 Lamiaceae plants—Perilla frutescens, Rosmarinus officinalis and Thymus vulgaris.

The polyphenol-enriched extracts of the 3 plants were prepared using macroporous adsorption resin. The content of total polyphenols and their common component-rosmarinic acid were determined. The antioxidant activities were evaluated by the scavenging capacities against 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) disodium salt positive ion radical (ABTS⁺·), as well as the ferric ion reducing capacity. The antimicrobial activities against Escherichia coli, Staphylococcus aureus and Aspergillus niger were evaluated by the minimum inhibitory concentration (MIC) and fungal inhibition rate.

After enrichment with macroporous resin, the content of rosmarinic acid in the polyphenol-enriched extracts of Perilla frutescens,Rosmarinus officinalis and Thymus vulgaris were (21.59±0.19)%, (20.56±0.03)% and (23.25±0.97)%, respectively. All 3 extracts exhibited strong antioxidant activities, which enhanced with the increase of total polyphenol and rosmarinic acid content; among them, the ferric ion reducing capacity of the Thymus vulgaris extract was particularly prominent, higher than that of the positive control group (vitamin C). Antimicrobial tests showed that the 3 extracts had certain inhibitory effects on Escherichia coli and Staphylococcus aureus, being particularly sensitive to Staphylococcus aureus. The MIC of the extracts from Perilla frutescens, Rosmarinus officinalis and Thymus vulgaris were 0.31, 0.63 and 0.31 mg/mL,respectively. In the antifungal test against Aspergillus niger, the Thymus vulgaris extract showed the best inhibitory effect, with an inhibition rate of (51.55±3.27)% on the 4th day, while Perilla frutescens showed no significant inhibitory effect.

The polyphenol-enriched extracts of the 3 Lamiaceae plants possess excellent antioxidant and antimicrobial activities, which are closely related to the enriched total polyphenols and rosmarinic acid. This provides a theoretical basis for the formulation development of plant-based natural food preservatives and preservation agents.

To determine the moisture retention rate, 1,1-diphenyl-2-trinitrophenylhydrazine (DPPH)free radical scavenging rate, fatty acid content and volatile components composition of the Brassica oleracea var. italica seeds oil and sprouts oil respectively.

Gas chromatography-mass spectrometry (GC-MS) was employed to analyze the fatty acid profiles and volatile constituents of Brassica oleracea var. italica seeds oil and sprouts oil.

The main fatty acids in Brassica oleracea var. italica seeds oil were erucic acid (31.94%) and oleic acid (31.28%), with a total unsaturated fatty acid content of 84.07%. For sprouts oil, the predominant fatty acids were erucic acid (29.43%)and oleic acid (29.62%), and the total unsaturated fatty acid content reached 85.21%. In addition, 57 kinds of compounds were identified in brassica oleracea var. italica seeds oil. Alcohols were the most abundant class both in species and content, with 15 kinds of alcohol compounds detected; cubanol, propanol and butanol were the major alcohols, while ethanol was present at a low level. Tert-butyl alaninate was the most abundant ester. Only 3 kinds of aldehydes, namely hexanal, nonanal and 2-propenal, were detected. By contrast, 26 kinds of volatile compounds were identified in sprouts oil, which lacked olefins compared with seeds oil. Aromatic compounds were the most diverse and abundant components in sprouts oil, with 6 kinds of species detected, among which 1-benzylindole was the most dominant.Meanwhile, Brassica oleracea var. italica seeds oil also exhibited moisturizing and strong DPPH radical scavenging activity. The ability of Brassica oleracea var. italica seed oil to scavenge DPPH free radicals showed a significant dose-dependent effect. When the mass fraction was 10%, the scavenging rate could reach 97%.

Brassica oleracea var. italica seeds oil and sprouts oil possess high safety and distinctive flavors, supporting their further development and utilization.

To establish a mothod for determination of oleuropein content in Oleaeuropaea L. related products by high performance liquid chromatography.

Ultrasonic-assisted extraction was employed to extract oleuropein from samples. The extraction conditions and mobile phase composition were optimized through single-factor experiments. The developed method was subjected to systematic method validation and subsequently applied to the determination of oleuropein content in commercially available products.

The optimal extraction conditions were 30% methanol with a solid-to-liquid ratio of 1:40 (g:mL), extraction temperature of 45 ℃ and extraction for 2 times. The chromatographic conditions consisted of acetonitrile-water (25:75, V:V) with a detection wavelength of 232 nm. Methodological validation demonstrated a good linear relationship (r²=0.999), and the precision [relative standard deviations (RSDs)<4%], repeatability (RSDs<3%) and spiked recovery (87.49%–115.00%) all met the required criteria.The oleuropein content in commercially available products typically ranges from 0 to 10 mg/g.

The method developed is highly sensitive and specific, can overcome complex matrix interferences, and is suitable for determining the content of oleuropein in Oleaeuropaea L. related products.

To investigate the inhibitory effect of hyperoside on α-amylase and its mechanism of exerting hypoglycemic activity.

The inhibitory effect and type of hyperoside on α-amylase were evaluated via enzymatic kinetics. Fluorescence spectroscopy was used to observe the effect of hyperoside on α-amylase activity and its underlying mechanism. Molecular docking technology was employed to elucidate the molecular interactions between hyperoside and α-amylase from a microscopic perspective.

Hyperoside exhibited a significant inhibitory effect on α-amylase, with a median inhibitory concentration (IC₅₀) of 1.081 mg/mL. The inhibition type was identified as reversible mixed competitive and non-competitive inhibition. Hyperoside induced a fluorescence quenching effect on α-amylase, and the quenching mode was determined to be static quenching. With the increase in hyperoside concentration, the maximum emission wavelength of α-amylase showed a blue shift, indicating a change in its spatial conformation. Molecular docking results revealed that hyperoside could enter the cavity of α-amylase,competitively bind to the active site, and interact with amino acid residues (THR163A, LEU165A, TRP59A,GLN63A, ARG195A, HIS201A, GLU233A, ASP300A and HIS305A) through hydrogen bonds and hydrophobic interactions. The binding energy between hyperoside and α-amylase was –8.3 kcal/mol, indicating a tight binding.

Hyperoside forms a complex with α-amylase, thereby hindering enzymatic catalysis of substrates,further diminishing enzymatic activity, and ultimately contributing to its hypoglycemic effect.

To optimize the extraction process for total flavonoids from pomelo flowers and investigate their antioxidant activity.

The extraction process of total flavonoids, the bioactive constituents from pomelo flower extracts, was optimized by single-factor experiments and orthogonal tests, while their antioxidant activities were evaluated.

The optimal extraction process conditions of total flavonoids from pomelo flowers were as follows:solid-liquid ratio 1:30 (g:mL), ethanol volume fraction 70% and ultrasonic time 50 min. Under these conditions, the extraction rate of total flavonoids was 12.44%. When the total flavonoid content was 49.86 mg/g, the scavenging rates of 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) disodium salt kation (ABTS⁺) and 1,1-diphenyl-2-picrylhydrazyl(DPPH) radicals reached 93.91% and 92.59%, respectively. The scavenging rate of hydroxyl radicals was as high as 99.51%, when the total flavonoid content was 24.93 mg/g.

Total flavonoids extracted from pomelo flowers exhibit excellent antioxidant capacity and possess superior application value in the food industry.

To investigate the extraction and purification processes of Cinnamomum cassia polyphenols and assess its in vitro biological activities.

A water extraction process combined with microfiltration and ultrafiltration membrane separation was employed to prepare a high-polyphenol, low-coumarin Cinnamomum cassia polyphenol extract (CPE).

The CPE contained 48.3% polyphenols and 0.022 mg/g coumarin. Compared with conventional aqueous extracts, the polyphenol content of CPE increased by 213.5%; the total content of procyanidin B₁ and B₂ increased by 148.7%, and the coumarin content decreased by 77.08%. In vitro experiments demonstrated that,compared with conventional aqueous extracts, CPE showed significantly stronger scavenging capacities for 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical cation(ABTS⁺), along with improved iron chelating ability and total reducing power. CPE exhibited stronger inhibitory activity against α-amylase and α-glucosidase.

The extraction and purification processes established in this study greatly improve the purity of Cinnamomum cassia polyphenols, and the obtained CPE exhibits stronger in vitro antioxidant activity and inhibitory capacity against carbohydrate digestive enzymes.

To investigate the dynamic changes of metabolites in Betula pendula Roth juice during the harvesting period, and analyze their intrinsic associations with physicochemical indices including soluble solid content,pH and electrical conductivity.

Betula pendula Roth juice collected on 7 consecutive days from the Yakeshi production region in Inner Mongolia, China, was pretreated by methanol-water (7:3, V:V) ultrasonic extraction in an ice-water bath, centrifugation and 0.22 μm membrane filtration, and was then analyzed by ultra performance liquid chromatography-quadrupole-orbitrap high resolution mass spectrometry (UPLC-Q-Exactive-MS) based untargeted metabolomics. Principal component analysis (PCA) was used to examine the overall variation of the metabolome,differential metabolites were screened with variable importance in projection (VIP)>1 and P<0.05, key metabolic pathways were resolved by UpSet plots, volcano plots and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis, and the soluble solid content, pH and electrical conductivity were determined to construct a metabolite-physicochemical index correlation network by Spearman rank correlation analysis.

The results showed that the metabolome of Betula pendula Roth juice could be divided into 3 stages along the harvesting period:D1–D3, stress-responsive metabolites such as alkaloids and organic acids were up-regulated, with log₂FC of +0.88 for pilocarpine and +2.68 for alpha-ketoglutaric acid, and as many as 119 kinds of differential metabolites (41 kinds of them unique to this comparison) were detected between D1 and D2; D4–D6, carbohydrates, lipids and amino acids predominated, the pentose phosphate pathway, starch and sucrose metabolism and phenylpropanoid biosynthesis were significantly enriched and alpha-linolenic acid (log₂FC=+4.21) and methyl jasmonate (log₂FC=+2.95) peaked at this stage; D7, most functional metabolites were down-regulated whereas aroma-associated benzenoids increased selectively,and only 4 kinds of differential metabolites were detected between D6 and D7, indicating that the metabolome tended to be stable. During the harvesting period, the pH, electrical conductivity and soluble solid content of Betula pendula Roth juice ranged from 4.11 to 6.99, from 211.16 to 608.40 μS/cm and from 0.80 to 2.66 °Brix, respectively; the correlation network showed that the soluble solid content was strongly and positively correlated with various carbohydrates and organic acids, and DL-malic acid and acetic acid acted as metabolic hub compounds simultaneously linking multiple physicochemical indices.

The metabolite composition of Betula pendula Roth juice undergoes a clearly stage-dependent evolution within a harvesting period of only 7 d, D4–D6 represent the stage richest in functional metabolites, and DL-malic acid and acetic acid can serve as candidate markers for quality evaluation; these findings provide a theoretical basis for scientifically defining the harvesting window and for the quality evaluation and high-value utilization of Betula pendula Roth juice.

To establish a method for qualitative and quantitative determination of Asini Corii Colla in Ejiao Yishou oral liquid by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).

The Ejiao Yishou oral liquid sample was digested with trypsin prior to HPLC-MS/MS analysis. A ZORBAX Eclipse Plus C₁₈ column (3.0 mm×150 mm, 1.8 μm) was adopted, using 0.1% formic acid aqueous solution-acetonitrile as mobile phase for gradient elution. Under the electrospray ionization mode, multi-reaction monitoring was carried out and the specific identification of Asini Corii Colla and the determination of the content of characteristic peptides of Asini Corii Colla were conducted.

The polypeptides derived from Asini Corii Colla exhibited good linearity relationships, with all correlation coefficients above 0.999. The relative standard deviations for instrumental precision,sample stability and method repeatability were all less than 4.0%, and the spiked recoveries at 3 concentration levels ranged from 88.30% to 100.22%. Asini Corii Colla was detected in all 126 batches of samples, while 91.3% of the samples had total content of the donkey-derived peptide A₁ and peptide A₂ below the proposed limit.

The established method is accurate, reliable and highly specific, and can be used for the quality control of Asini Corii Colla in the Ejiao Yishou oral liquid.

To investigate the effects of different storage durations on the volatile flavor components of Osmanthus fragrans‑aged liqueur by gas chromatography‑tandem mass spectrometry (GC‑MS/MS).

Taking Chuanshanyan cave‑aged Osmanthus fragrans‑aged liqueur as the research object, 3 groups of samples were selected:initial bottling stage, after 2 years of storage durations and after 3 years of storage durations. GC‑MS/MSwas used to qualitatively detect and compare the volatile flavor components of the Osmanthus fragrans‑aged liqueur at different storage durations.

With increasing storage durations, the total number of volatile flavor compounds in the Osmanthus fragrans‑aged liqueur showed an initial increase followed by a decrease: 29 kinds of compounds were detected at the initial bottling stage, which increased to 32 kinds of after 2 years of storage durations, and further decreased to 27 kinds of after 3 years of storage durations. The number of alcohol species remained stable across all 3 stages, but their content gradually decreased with prolonged storage. The numbers of ester and aldehyde both exhibited an initial increase followed by a decline, with esters decreasing significantly after 3 years of storage, and acids increasing by one species at the 2‑year stage and then remaining stable. Other compounds gradually diminished during storage and completely disappeared after 3 years. During the aging process, unstable and pungent flavor components gradually diminished.

This study reveals the evolution patterns of volatile flavor compounds in Osmanthus fragrans‑aged liqueur during cave aging, clarifies the differential responses of various flavor components to the storage duration, and makes the aroma structure of structure more streamlined and coordinated. It can provide a reference for controlling reasonable storage durations and ensuring stable quality production of this type of characteristic fruit liqueur.

To establish an electrochemical sensing method based on a copper oxide nanoparticle-modified electrode for the determination of carbendazim in foods.

The 3 kinds of modified electrodes were prepared by the drop-coating method. The screen-printed electrode (SPE) and the 3 kinds of modified electrodes were electrochemically characterized and screened by cyclic voltammetry and electrochemical impedance spectroscopy. The electrochemical response behavior of carbendazim on the surface of copper oxide nanoparticle-modified SPE (CuONPs/SPE) and the effects of scan rate were investigated by cyclic voltammetry. The supporting electrolyte and pH were optimized by differential pulse voltammetry, and the analytical performance such as the limit of detection and repeatability of the method was investigated.

The oxidation peak current of carbendazim on different electrode surfaces showed significant differences. Among them, CuONPs/SPE exhibited the largest oxidation peak current response. Under the optimal conditions, the oxidation peak current showed a good linear relationship with carbendazim concentration in the range of 0.1–200.0 µmol/L, and the limit of detection was 29.6 nmol/L.This method was applied to detect fresh shiitake mushrooms, fresh yam and grass carp samples. The spiked recoveries were 92.7%–113.9%, 84.9%–110.2% and 89.0%–93.5%, respectively.

The established CuONPs/SPE electrochemical sensing method has the advantages of simple electrode preparation, low detection cost and rapid response. It is suitable for the rapid determination of carbendazim content in various actual samples.

To comparatively study the Bact/Alert 3D microbiological detection system method(referred to as the instrument method) in the detection of commercial sterility items of ultra-high temperature instantaneous (UHT) sterilized milk, pure milk and room-temperature yogurt, with reference to the national standard methods.

The inclusivity of the instrument method was assessed by performing suitability tests on 36 kinds of microbial species. The sensitivity and detection time of the 2 methods were compared by detecting UHT pure milk artificially contaminated with Bacillus licheniformis and room-temperature yogurt artificially contaminated with Candida albicans using the GB 4789.26—2023 National food safety standard-Food microbiological examination-Commercial sterility testing (national standard method) and the instrument method; sensitivity was compared using 50% limit of detection (LOD₅₀), and the detection timeliness was evaluated. Additionally, the sensitivity was validated across 5 laboratories.

The instrument method demonstrated 100% inclusivity for the 36 kinds of microbial species tested. The LOD₅₀ of the instrument method was slightly lower than that of the national standard method for UHT pure milk with Bacillus licheniformis, but slightly higher for room-temperature yogurt with Candida albicans. The time to positivity for the instrument method was significantly shorter than that of the national standard method.

The instrument method shows good applicability for the 36 kinds of microbial species tested.While there are slight differences in sensitivity compared to the national standard method depending on the sample matrix, the instrument method offers superior timeliness.

To systematically evaluate the quality of Perilla frutescens seeds from diverse germplasm sources by integrating principal component analysis with the technique for order preference by similarity to ideal solution (TOPSIS) using a comprehensive multi-indicator framework, and to identify and screen for elite Perilla frutescens seed germplasm resources.

The total flavonoids, rosmarinic acid, thousand-seed weight, moisture content, oil content and relative content of fatty acids in the seeds of 31 purple Perilla frutescens germplasms were tested. Principal component analysis was used to screen the key indicators affecting the quality of purple Perilla frutescens seeds, and TOPSIS was employed for comprehensive quality evaluation. Systematic cluster analysis was used for resource classification.

The total flavonoids and rosmarinic acid contents of the 28th germplasm of purple Perilla frutescens seeds were significantly higher than those of other germplasms; the oil content of the 3th germplasm was the highest at 44.67%; the fatty acid test results indicated that the fatty acids in purple Perilla frutescens seeds were mainly composed of palmitic acid, stearic acid, oleic acid, linoleic acid and α-linolenic acid; the 4th germplasm resource had the highest α-linolenic acid content of 75.47%. Principal component analysis extracted 3 principal components with eigenvalues greater than 1. Based on the criterion that the absolute value of the loading value is greater than 0.4, the indicators with the largest loading values in different directions on each principal component were selected as the key indicators for comprehensive quality evaluation, and then the TOPSIS method was used for comprehensive evaluation. According to the relative proximity degree ranking, the 28th germplasm was the one with the highest comprehensive quality, possessing both high medicinal components and good oil quality. Systematic cluster analysis divided the 31 purple Perilla frutescens seeds into 4 categories: high medicinal component-high-quality oil use type, balanced medicinal and oil type, oil use specialized type and basic type.

This study established a multi-index comprehensive evaluation method for the quality of purple Perilla frutescens seeds, providing a theoretical basis for the development of purple Perilla frutescens functional oils and the selection of medicinal resources.

To compare the effects of roasting pretreatment combined with different oil-extraction methods on the quality, antioxidant activity and volatile aroma of raw and roasted flaxseed oils.

Raw and roasted flaxseeds were used as materials, and oil samples were prepared by supercritical CO₂ extraction (SC-CO₂) and spiral pressing (SP). Their basic physicochemical properties, fatty acid composition, total phenol and tocopherol content,antioxidant activities [1,1-diphenyl-2-picrylhydrazyl radical (DPPH), 2,2’-azino-bis(3- ethylbenzothiazoline-6-sulfonate acid)diammonium salt cation (ABTS⁺) and ferric reducing antioxidant power (FRAP)] and volatile aroma components were determined, and the effects of different processing methods on oil quality were analyzed.

Both different oil-extraction methods and roasting pretreatment significantly affected the quality of flaxseed oil. The SP roasted group showed the highest iodine value, peroxide value and relative content of polyunsaturated fatty acids and total unsaturated fatty acids, reaching 178.00 g/100 g, 0.13 g/100 g, 69.56% and 89.61%, respectively. The untreated SC-CO₂ group e x h i b i t e d t h e h i g h e s t a c i d v a l u e a n d t o c o p h e r o l c o n t e n t, a t 2.0 0 m g/g a n d 3.96 mg α-TE/100 g, respectively. The roasted SP group had the highest total phenolic content (0.62 mg/g), which was not significantly different from that of the untreated SC-CO₂ group (0.60 mg/g, P>0.05). In terms of antioxidant activity,the untreated SP group exhibited the strongest ABTS⁺ radical scavenging capacity, whereas the SP roasted group showed the highest FRAP. Volatile aroma analysis indicated that roasting combined with SP promoted the accumulation of volatile compounds such as aldehydes, ketones, alcohols and pyrazines.

Roasting pretreatment and different oil-extraction methods significantly affects the nutritional quality, antioxidant activity and volatile aroma characteristics of flaxseed oil, providing a theoretical basis for optimizing flaxseed oil processing technology and its high-value utilization.

To investigate the speciation composition of arsenic and the differences in arsenic bioaccessibility among various edible mushrooms, and to evaluate their impacts on dietary health risk assessment outcomes.

The 18 kinds of common edible mushroom species collected in Guizhou Province were selected as research materials. Arsenic speciation analysis and in vitro physiologically based extraction test were performed.Combined with estimated daily intake, target hazard quotient and target cancer risk models, the transformation pattern of arsenic species during gastrointestinal digestion was quantitatively elucidated, and subsequent health risk assessment was conducted.

The total arsenic concentrations in the tested edible mushrooms ranged from 0.0245 to 0.7458 mg/kg.Only Agaricus blazei exceeded the national limit specified in GB 2762—2022 National food safety standards-Limits of contaminants in food (stipulates 0.5 mg/kg). The proportion of inorganic arsenic to total arsenic varied from 2.83% to 90.04%, with its bioaccessibility ranging between 0.00 and 70.42%, showing significant interspecies differences. After bioaccessibility correction, the concentration of toxic inorganic arsenic decreased to 0–0.1138 mg/kg, meanwhile, the estimated daily intake, target hazard quotient and target cancer risk of inorganic arsenic in digestive fluids were reduced to values closer to the actual human exposure levels.

Arsenic speciation and the bioaccessibility during gastrointestinal digestion exert prominent influences on health risk assessment of arsenic in edible mushrooms.Incorporating both indicators into the risk assessment framework can substantially improve the accuracy of risk evaluation, and provide scientific evidence for the formulation of arsenic pollution prevention and control strategies as well as food safety standards for edible mushrooms.

To systematically evaluate the multi-dimensional quality attributes of Lycium barbarum L.shaped by geographical terroir.

This study conducted a comprehensive assessment of 95 representative Lycium barbarum L. samples from the 4 major production areas in northwest China, namely Gansu (GS), Ningxia (NX),Qinghai (QH) and Xinjiang (XJ). The morphology, nutritional components, flavor metabolites and antioxidant capacity were analyzed, and the analysis was carried out using multiple chemometrics methods.

The longitudinal diameter of the fruits in the QH region was the most prominent, averaging 21.86 mm, which was significantly higher than that in other regions (P<0.05). However, the fruits from the XJ region were relatively short in longitudinal diameter (averaging 16.40 mm); the QH region demonstrated the highest standard of commercial quality, followed closely by the XJ region. Analysis of the basic nutritional components of Lycium barbarum L. from 4 production areas: samples from the XJ production area showed lower moisture content (average 12.39 g/100 g) and protein content(average 12.86 g/100 g), and their ash content (20.15 g/100 g) was significantly higher than that of the other three regions. The crude fat content (average 0.61 g/100 g) was the lowest among the 4 production areas. The content of vitamin C was relatively high. Lycium barbarum L. from all production areas had demonstrated excellent free radical scavenging capabilities, but they showed different free radical preferences. The sensory quality showed significant characteristic differences in different production areas (P<0.05). The aroma and taste of Lycium barbarum L. from the XJ production area were significantly higher than those from other regions (P<0.05), and the color showed obvious abnormal pigment deposition or a tendency of browning of the fruit skin.

There are significant morphological differentiations among different production areas, and this variation is influenced by the interaction between genetics and the environment. This study identify 12 key biomarkers driving regional differentiation, providing a scientific basis for the origin traceability, quality standardization and variety screening of Lycium barbarum L. in different ecological environments.

To isolate and screen lactic acid bacteria with antioxidant capacity from Chaenomeles speciosa.

The probiotic properties and antioxidant capacity of Chaenomeles speciosa were evaluated by screening, isolating and identifying the lactic acid bacteria strains in it.

The 4 dominant strains, namely MG3,MG9, MG13 and MG21, were identified as Lactiplantibacillus plantarum. Strain MG13 exhibited excellent probiotic performance and strong antioxidant activity. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging rates of its fermentation supernatant and bacterial suspension reached 90.93% and 59.30%, respectively; the hydroxyl radical scavenging rates were 93.47% and 49.19%; and the superoxide anion radical scavenging rates were 91.00% and 72.25%.When MG13 was applied to ferment Chaenomeles speciosa juice, the antioxidant activity of the juice was significantly improved. Compared with unfermented juice, the DPPH and 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid)radical scavenging rates of fermented juice increased significantly to 78.91% and 87.02%, respectively. The content of flavonoids and polyphenols in fermented juice rose by 55.44% and 30.25%, which effectively enhanced the functional properties of Chaenomeles speciosa juice.

Fermentation with strain MG13 significantly optimizes the quality of Chaenomeles speciosa juice. This study provides theoretical support and high-quality strain resources for the microbial fermentation and utilization of medicinal and edible plant materials.

To investigate the hepatotoxic effects of nano-sized and food-grade TiO₂ on mice liver.

A total of 80 Kunming mice was randomly divided into the control group and TiO₂ exposure groups with different particle sizes. The mice were intragastrically administered with nano-sized titanium dioxide (Nano-TiO₂) or food-grade TiO₂ (E171) suspension at doses of 50, 150 and 500 mg/kg BW for 14 consecutive days. Purified water was used as the negative control. At the end of the experiment related biochemical indexes were determined, the liver coefficient was calculated and liver antioxidant indexes were detected. Mice AML12 cells were treated with Nano-TiO₂ or E171 suspension at concentrations of 0, 25, 50 and 100 μg/mL, and cell viability and intracellular reactive oxygen species (ROS) content were subsequently measured.

After 14 days of exposure, neither nano-sized nor food-grade TiO₂ exerted significant effects on body weight, liver coefficient and liver-related biochemical indexes in mice. Nano-TiO₂ induced obvious oxidative damage in the liver of mice, while E171 had no significant influence on hepatic antioxidant indexes. In all dose groups, Nano-TiO₂ reduced cell viability and increased intracellular ROS levels.Decreased cell viability and elevated ROS content were only observed in the 100 μg/mL E171 treatment group.

Under the research same exposure conditions, the hepatic oxidative toxicity of Nano-sized TiO₂ is stronger than that of the food additive E171. This research provides a scientific basis for the safe application of food additive E171.

To explore the genomic characteristics and drug resistance of Salmonella Rissen in Yongchuan District, Chongqing from 2023 to 2025.

The 10 strains of foodborne Salmonella Rissen isolated in Yongchuan District, Chongqing City from 2023 to 2025 were identified, subjected to molecular identification, drug sensitivity tests and whole-genome sequencing. Based on sequencing data, molecular tracing and prediction of drug resistance genes were conducted.

The 10 strains of Salmonella Rissen had a resistance rate of 100.00% to tetracycline (TET), and the resistance rates to ampicillin (AMP), ampicillin/sulbactam (AMS), chloramphenicol (CHL),florfenicol (FFC) and trimethoprim/sulfamethoxazole (SXT) were greater than or equal to 50%, and all showed multi-drug resistance strains. All of the Salmonella Rissen carried a total of 94 drug resistance genes of 8 types. The prediction results of drug resistance genes were highly consistent with the drug resistance phenotype. A total of 9 virulence islands were carried. All isolates carried C63PI, SPI-1–3, SPI-5, SPI-8 and SPI-9 virulence islands.Phylogenetic analysis revealed that in this study, Salmonella Rissen was more closely related to the Eurasian branch, and there was clustering between the food strain and the case strain.

In Yongchuan District, the problem of drug resistance and multi-drug resistance of Salmonella Rissen in foodborne diseases is particularly prominent, the drug resistance phenotype is highly correlated with the genotype, and there is clustering between food isolates and human isolates. The quarantine of pathogenic bacteria and food hygiene education in the food trade and circulation links should be strengthened. Meanwhile, it is suggested to establish a whole-genome combined drug resistance analysis database of Salmonella in this region, strengthen gene monitoring and research on drug resistance mechanisms, achieve precise traceability of pathogenic bacteria, realize networked monitoring of pathogenic bacteria, thereby optimizing drug resistance prevention and control in the region, guiding clinical medication, and providing a scientific basis for achieving the health of the entire population.

To investigate the contamination level, antimicrobial resistance patterns and health risks to consumers of Campylobacter in fresh poultry meat in Beijing, and evaluate its public health significance within the food safety context.

A total of 738 fresh poultry meat samples were collected from farmers’ markets and supermarkets in Beijing between 2021 and 2023. Campylobacter was isolated using a membrane filtration-based method and identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The minimum inhibitory concentrations (MICs) of 11 kinds of commonly used antimicrobial agents were determined using the agar dilution method, and the drug resistance characteristics were analyzed. Based on residents’ poultry meat consumption behavior,Campylobacter contamination data and relevant literature parameters, a quantitative microbial risk assessment model was constructed to estimate the infection risk of the population and conduct sensitivity analysis.

The overall isolation rate of Campylobacter was 43.63%, with a higher detection rate in samples collected from farmers’ markets than those from supermarkets. A total of 343 Campylobacter strains were isolated in this study. Severe antimicrobial resistance to fluoroquinolones and tetracyclines, as well as a high multidrug resistance rate, were observed among the isolates. Specifically, the multidrug resistance rate of Campylobacter coli reached 87.83%. Risk assessment indicated that the probability of Campylobacter infection per consumption of fresh poultry meat among residents in Beijing was 4.16×10^–5, leading to approximately 72073 annual infection cases, with a considerable proportion attributed to multi-drug resistance strains. Sensitivity analysis identified cross-contamination behaviors, such as failure to wash hands or replace cutting boards, were major risk factors.

Fresh poultry meat in Beijing is heavily contaminated with Campylobacter, and antimicrobial resistance pose a prominent problem. It is necessary to strengthen microbial control throughout the poultry meat supply chain, standardize the application of antibiotics, raise residents’ awareness of food safety, and prevent and control cross-contamination, so as to reduce the incidence of foodborne diseases.