To establish an analytical method for the simultaneous determination of 25 kinds of mineral elements in Zhaotong Gastrodia elata Blume by inductively coupled plasma mass spectrometry, and evaluate and distinguish the differences in element content among Zhaotong Gastrodia elata Blume samples collected from different counties and districts.

The 39 samples of Zhaotong Gastrodia elata Blume collected from 8 districts in Zhaotong City were subjected to microwave digestion, and the concentrations of 25 kinds of elements were determined by ICP-MS. The validity of the method was verified through linear relationships, limits of detection,limits of quantitation, repeatability and spiked recovery rates. A fingerprint profile of mineral elements in Zhaotong Gastrodia elata Blume was established, and statistical software was used in conjunction with principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) to perform origin analysis and identification.

The results showed that the method exhibited good linearity (r>0.995), high repeatability(relative standard deviation of 0.8%–7.1%), and high accuracy (spiked recovery of 93.2%–106.5%); the analytical results indicated that Zhaotong Gastrodia elata Blume was rich in mineral elements and exhibited distinct elemental characteristics of high potassium and low sodium. Through fingerprint analysis, elements such as K, Fe, Mn, Zn, Sr,Ba, and Al were identified as characteristic elements of Zhaotong Gastrodia elata Blume; PCA and OPLS-DA could be used to achieve preliminary differentiation among Zhaotong Gastrodia elata Blume from different counties, with 7 kinds of elements (Fe, Al, Mn, Sr, Ba, K and Zn) identified as playing a key role in classifying samples from different production areas.

The inductively coupled plasma mass spectrometry method can simultaneously determine multiple metallic elements in Zhaotong Gastrodia elata Blume. By analyzing the content and variation patterns of mineral elements in Zhaotong Gastrodia elata Blume, this study provides a reference for the mineral nutritional evaluation and quality safety risk assessment of Zhaotong Gastrodia elata Blume, and offers data support for its diversified resource development and utilization, product promotion and traceability.

To construct a fluorescent biosensor composed of 2’-fluoro-substituted nucleic acid aptamer (2’F-Apt) and graphene oxide (GO) for the highly sensitive and specific detection of Staphylococcus aureus in prepackaged foods.

The biosensor was fabricated via non-covalent adsorption and assembly between 2’F-Apt and GO. The fluorescence of the aptamer was quenched by GO. In the presence of target bacteria, 2’F-Apt specifically bound to surface proteins of the bacteria and detached from GO, resulting in the recovery of fluorescence signal, which enabled the quantitative detection of samples.

Compared with unmodified nucleic acids,2’-fluoro substitution reduced the conformational constraints of nucleic acid strands and improved molecular flexibility. It also increased binding sites and specific surface area, strengthened the interaction between 2’F-Apt and GO, effectively inhibited non-specific dissociation and reduced false-positive results. Meanwhile, the target recognition capability and detection sensitivity were enhanced. The test results showed that the linear detection range of the 2’F-Apt/GO biosensor for Staphylococcus aureus was 10 to 10⁹ CFU/mL, with a limit of detection of 5 CFU/mL, presenting excellent detection performance.

The biosensor constructes in this study features simple preparation, good universality and high sensitivity, and can be applied to the rapid detection of Staphylococcus aureus in prepackaged foods.

To establish a dual recombinase aided amplification (RAA) and clustered regularly interspaced short palindromic repeats-associated protein (CRISPR-Cas) technology for the rapid detection of Bacillus cereus and Listeria monocytogenes.

Using the gyrB gene and the listeriolysin virulence gene hly as detection targets, RAA primers and crRNAs were designed. Their sensitivity and specificity were analyzed and the positive detection rate of this method was evaluated using actual samples.

The dual RAA/CRISPR-Cas12a technology could detect 0.0001 ng/μL of Bacillus cereus genomic DNA and 0.001 ng/μL of Listeria monocytogenes genomic DNA within 40 minutes at 37 ℃, with no cross-reactivity against other foodborne pathogens (Salmonella spp., Staphylococcus aureus, Escherichia coli, Clostridium perfringens, Vibrio parahaemolyticus). Using real-time polymerase chain reaction as a reference, 30 beef samples were tested. The RAA/CRISPR-Cas12a method detected 5 positive samples, achieving a positive detection rate of 100%, consistent with the real-time polymerase chain reaction method.

The dual RAA/CRISPR-Cas12a detection method established in this study offers rapid detection, high sensitivity, and high specificity, making it suitable for detecting Bacillus cereus and Listeria monocytogenes in food.

To evaluate the risk of pesticide residues in Fragaria ananassa, and analyze the correlation between pesticide residues and the quality of Fragaria ananassa.

A total of 156 Fragaria ananassa samples were analyzed for pesticide residues. Based on the acquired pesticide residue data in Fragaria ananassa samples, the acute dietary risk of the target fruit was assessed by applying relevant maximum residue limits and dietary exposure assessment methodologies. Meanwhile, key quality parameters of the Fragaria ananassa-including vitamin C (VC), soluble sugar, titratable acid, pectin, solids and hardness were determined. The correlation between detected pesticide residues and these quality parameters was then analyzed.

A total of 19 pesticide residues were detected among the 104 kinds of target pesticides across 156 sample batches.Pesticide-free samples accounted for 24.36% of the total, while samples containing multiple pesticide residues (≥3 types) represented 15.39%. Among the detected compounds, the plant growth regulator chlormequat showed the highest residual level, with a maximum concentration of 0.408 mg/kg and a detection rate of 46.15%. Among fungicides, boscalid had the highest detection rate (21.79%). Spirodiclofen was the insecticide with the highest detection rate among insecticides (12.18%). Notably, the pesticides with insecticidal effects detected had not been registered on Fragaria ananassa. The acute dietary intake risk was below 1. VC content was positively correlated with chlormequat. Soluble sugar showed a positive correlation with procymidone, positive correlation with carbendazim, and a negative correlation with prochloraz. Titratable acid was negatively correlated with chlorantraniliprole, dinotefuran and trifloxystrobin. Pectin content was positively correlated with chlormequat, while total solids were negatively correlated with prochloraz. Hardness exhibited no significant correlation with any pesticide residues. The detection rate of pesticide residues in Fragaria ananassa was high, with a wide variety of residues identified. Both cypermethrin and dimethomorph were found to exceed the standard limits (0.64%),however, no short term dietary intake risk was observed. Appropriate application of the plant growth regulator chlormequat had a positive effect on the VC content of Fragaria ananassa. But chlormequat was not registered for Fragaria ananassa, and further screening of alternative agents was required.

This study assesses the dietary risk of pesticide residues in Fragaria ananassa and investigates their association with key nutritional quality indicators. The integrated safety-quality assessment framework established can be extended to other high-value produce, providing practical value for guiding evidence-based pesticide application and enhancing the overall quality and safety of agricultural products.

To compare the foreleg meat quality between Gannan Juema pigs and Duroc-Landrace-Yorkshire pigs.

The edible qualities, nutritional quality and antioxidant capacity of the foreleg meat from 8 to 10 month-old of Gannan Juema pigs and Duroc-Landrace-Yorkshire pigs were analyzed.

The a^*, shear force, hardness, cohesiveness, protein content, content of histidine, arginine, alanine, proline, valine,linoleic acid, α-linolenic acid, eicosenoic acid, docosenoic acid, arachidonic acid, docosahexaenoic acid, iron element,copper element and zinc element content were significantly higher compared with Duroc-Landrace-Yorkshire pork(P<0.05). Conversely, L^*, b^*, fat content, aspartic acid, glutamic acid, serine, threonine, methionine, leucine and lysine were significantly lower in Gannan Juema pork (P<0.05). Compared with Duroc-Landrace-Yorkshire pork, Gannan Juema pork exhibited superior color characteristics, compact and tough texture, along with high-protein and low-fat nutritional profiles. Its amino acid composition was closer to the ideal protein pattern recommended by Food and Agriculture Organization of the United Nations/World Health Organization. Moreover, Gannan Juema pork contained lower saturated fatty acids, higher polyunsaturated fatty acids, abundant mineral elements and high antioxidant enzyme activity.

Gannan Juema pork has excellent edible quality, nutritional quality and antioxidant capacity,which meets consumers’ demand for healthy and high-quality meat products and has good market development prospects and promotion value.

To investigate the amino acid composition characteristics and nutritional value of Cyperus esculentus from 11 provinces and autonomous regions in China (Xinjiang, Hebei, Henan, Shandong, Hunan, Ningxia,Yunnan, Inner Mongolia, Heilongjiang, Liaoning and Jilin), and establish a geolocation model based on amino acid composition.

Amino acid analyzers were used to test Cyperus esculentus samples from different varieties across these 11 provinces and autonomous regions, analyzing the effects of origin and varying climatic conditions on amino acid content. From a nutritional perspective, the nutritional value of Cyperus esculentus amino acids across the 11 provinces and autonomous regions was comprehensively evaluated through analysis of essential amino acids,branched-chain amino acid composition and amino acid scoring results.

Cyperus esculentus exhibited a rich variety of amino acids, with essential amino acids accounting for 24%–36% and branched-chain amino acids ranging from 12.02%–17.43%. Amino acid scoring indicated that methionine was the primary limiting amino acid in Cyperus esculentus across all 11 provinces and autonomous regions. In actual consumption, it was recommended to address methionine deficiency through dietary combinations or nutritional fortification. Under the subtropical monsoon climate of Southwest Asia, the levels of glutamic acid and aspartic were significantly higher than under other climatic conditions. Using chemometric software, 3 kinds of models—K-nearest neighbor algorithm (KNN), partial least squares discriminant analysis (PLS-DA) and support vector machine (SVM)—were applied for origin tracing. The KNN model demonstrated the best performance, achieving a training set recognition rate of 96.97% and a cross-validation recognition rate of 98.99%.

This study investigates amino acid content variations in Cyperus esculentus across different provinces and autonomous regions, providing a reference for Cyperus esculentus cultivation and subsequent industrialization of Cyperus esculentus products.

To establish an analytical method for the simultaneous determination of 36 kinds of veterinary drug residues (including 19 kinds of sulfonamides, 13 kinds of quinolones and 4 kinds of tetracyclines) in sea duck eggs by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

Sea duck egg samples were extracted with 0.2 mL of 10% potassium ferrocyanide solution and 0.2 mL of 20% zinc acetate solution, and purified using an Oasis HLB solid-phase extraction column. Separation of the target analytes was performed on a Waters ACQUITY UPLC BEH C₁₈ column using a gradient elution program. The mobile phase consisted of 0.1% formic acid aqueous solution and acetonitrile containing 0.1% formic acid data acquisition for qualitative and quantitative analysis was carried out in the positive electrospray ionization mode using multiple reaction monitoring, with quantification by the external standard method.

The linear correlations of sulfonamides, quinolones and tetracyclines were favorable in the concentration range of 5–250 μg/kg(r²≥0.9969). The average recoveries ranged from 87.8% to 101.2%, with relative standard deviations of 1.25%–4.53%. The limits of detection and limits of quantitation were 0.05–5.11 μg/kg and 0.18–17.04 μg/kg,respectively.

The established method is rapid, simple, sensitive and reliable, and is suitable for the simultaneous qualitative and quantitative detection of sulfonamide, quinolone and tetracycline veterinary drug residues in large batches of sea duck eggs.