Objective To study the residual behavior and dietary risk assessment of oxine-copper in Prunus persica. Methods The samples were extracted by homogenate with acetonitrile-10% acetic solution, centrifuged after salting out, detected by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), and quantified by external standard method. Results There was a good linear relationship in the range of 0.0025 to 0.2500 mg/L, and the correlation coefficients was 0.999; in the range of 0.01 to 1.00 mg/kg; the average recoveries of oxine-copper in Prunus persica ranged from 86% to 102%, with the relative standard deviation was 1.4% to 6.0%, and the limit of quantification was 0.01 mg/kg. The dissipation process of oxine-copper in Prunus persica followed a first-order kinetic model. The dissipation half-lives of oxine-copper in Prunus persica from Ningxia, Beijing, Shandong and Sichuan were 13.9, 9.9, 7.7 and 23.1 days, respectively, and the correlation coefficients ranged from 0.635 to 0.948, after 14 days of application, the maximum residual amount of oxine-copper in Prunus persica samples was 0.920 mg/kg. The dietary risk assessment showed that after 14 d of application, the probability of dietary intake risk in the general population was far less than 100%. Conclusion This method is simple, accurate, and highly sensitive, and is suitable for the residual detection oxine-copper in Prunus persica. The final residue tests show that the amount of copper quinoline residue does not exceed the established maximum residue limits, and does not pose an unacceptable risk to the health of the general population.

Objective To investigate the sensory changes of camel meat stored at different temperatures (4, 15, and 25 ℃) and establish a shelf-life prediction model based on sensory differences. Methods By simulating actual storage conditions, the changes in color, electronic tongue taste indices (umami, saltiness, sourness, sweetness, etc.), and electronic nose olfactory indicators (nitrogen oxides, methane, sulfides, etc.) of camel meat were analyzed. Zero-order reaction kinetics models and the Arrhenius equation were used to fit the data, establishing a shelf-life prediction model based on color, electronic tongue and electronic nose metrics. The model was validated using pH, total bacterial count and total volatile basic nitrogen (TVB-N). Results At 4 ℃, there was no significant change in the lightness (L^*) and redness (a^*) of camel meat (P>0.05), while the a^* value significantly decreased at 15 ℃ and 25 ℃ (P<0.05), and yellowness (b^*) showed an upward trend across all temperatures. Taste analysis revealed that umami (AEE), saltiness (CT0), sourness (CA0) and astringency (AE1) intensities increased with time and temperature, whereas sweetness (GL1) intensity decreased. Electronic nose detection found that concentrations of nitrogen oxides (W5S), methane (W1S), sulfides and terpenes (W1W) and alcohol compounds (W2S) significantly increased over storage time. The calculated shelf lives based on color, electronic tongue and electronic nose were 7.23, 6.24 and 6.12 d, respectively. Verification using camel meat stored at 6 ℃ showed high prediction accuracy of the electronic tongue model, but significant discrepancies were observed among shelf lives predicted by different physicochemical indicators (e.g., total bacterial count, pH, TVB-N). Conclusion This study successfully establish a shelf-life prediction model based on sensory characteristics. The prediction models established based on the electronic tongue and electronic nose show good agreement with validation results based on pH, with relative errors of -2.80% and -4.67%, respectively. Different physicochemical indicators have varying degrees of strictness towards meat quality requirements, with total bacterial count being the most stringent and TVB-N relatively more lenient. This study provides a reference for the quality monitoring of fresh camel meat.

Objective To systematically analyze the characteristics of volatile compounds in the crude fat of Trachinotus ovatus by gas chromatography-ion mobility spectrometry (GC-IMS) combined with electronic-nose. Methods GC-IMS was used to qualitatively and quantitatively analyze the volatile compounds in the crude fat of different parts (head, abdomen and viscera) of Trachinotus ovatus, focusing on the identification of differences in key flavor components such as alcohols, ketones, acids and aldehydes. Combined with electronic-nose technology, the overall flavor profile of crude fat in each part was characterized to further evaluate the contribution of major volatile compounds to flavor formation. Results The crude fat in different parts of Trachinotus ovatus belonged to high-quality lipids, but there were significant differences in the composition of volatile components. The fish head group was mainly composed of alcohols and ketones. The abdominal group was dominated by alcohols, alkanes and acids; the visceral group contained higher volatile acids. Conclusion This study reveals the differences in volatile compounds in different parts of Trachinotus ovatus, provides theoretical support for its flavor regulation, and also provides guidance for the high-value utilization of by-products such as viscera.

Objective To establish an enzyme-linked immunosorbent assay method for detecting soybean agglutinin in legume foods. Methods After washed the sample, added phosphate buffer solution and homogenize it thoroughly. After centrifugation and purification, collected the supernatant and determine it by enzyme-linked immunosorbent assay. Quantify it used an enzyme-linked immunosorbent assay reader. Result In the linear range of 0-400 μg/mL, the linear equation of soybean agglutinin obtained was Y=0.0021X+0.0528, r=0.9998. The detection limit of this method was 125 mg/kg, the recovery rate was between 99.17% and 101.20%, and the relative standard deviation was between 1.27%-2.24%. Conclusion This method is easy to operate, has good specificity, and the antigen concentration is directly proportional to the OD₄₅₀ value. Applicable to the detection of soybean agglutinin poisoning incidents by grassroots disease control centers.

Objective To explore the antioxidant effects and fatty acid content of walnut oil derived from different substrates. Methods Gas chromatography-mass spectrometry (GC-MS) was used to analyze the fatty acid content in walnut oil and unqualified walnut oil at different pressing temperatures. Single variable control method was used to study the antioxidant effects of walnut oil with different air content. After adding a complex of natural antioxidants, fat soluble rosemary at 0.04 g/100 g and vitamin E at 0.1 g/100 g, 2 sets of experiments were conducted. The first set contained 100, 200, 300, 400 and 500 mL oil samples in 500 mL glass bottles, while the second set contained 100 mL oil samples in 100, 250 and 500 mL glass bottles. The samples were rapidly oxidized in a constant temperature drying oven at 63 ℃±1 ℃ and kept at that temperature for 70 days. The aroma, taste, peroxide value and acid value of the oil samples were measured every 10 days. Results The fatty acids in walnut oil were palmitic acid, linoleic acid, stearic acid and oleic acid. The content of fatty acids varies with storage time and pressing temperature, and the unqualified oil sample didn’t contain oleic acid. The walnut oil pressure pressing temperature of 130-140 ℃ had the best quality. The 2 sets of experiments had confirmed that walnut oil with lower air content could be stored for a longer period of time, up to a maximum of 100 days. Conclusion The less contact with air during storage or the decrease in the ratio of initial air volume to initial oil sample volume, the longer the shelf life. The conduct of this study provides a reference for the storage conditions of walnut oil.

Objective To establish an analytical method for the rapid determination of 5 kinds of peptide toxins in samples from wild mushroom poisoning incidents by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Methods The remaining mushrooms and patient urine samples were extracted by methanol, purified by 250 mg N-propyl ethylenediamine (PSA), and separated by Waters CORTECS C₁₈⁺ liquid chromatography column. The mobile phase consisted of methanol and 2 mmol/L ammonium acetate (containing 0.1% formic acid) under gradient elution. They were determined by HPLC-MS/MS. Results The 5 kinds of peptide toxins had a good linear relationship (r>0.997) at the concentration 10.0-500.0 µg/L. The limits of detection (LODs) of 5 kinds of peptide toxins in the mushroom samples were 2.0-3.0 µg/kg, the limits of quantification (LOQs) were 5.0-10.0 µg/kg. In the urine samples, the LODs of 5 kinds of peptide toxins were 0.8-1.2 µg/L, the LOQs were 2.0-4.0 µg/L. The recoveries of method were 60.1%-94.9%, and the relative standard deviations were 2.0%-17.7% (n=6). Conclusion This method is accurate and rapid, and suitable for determination of peptide toxins in residual mushroom and patient urine samples from wild mushroom poisoning incidents.

Objective To rapidly screen the elemental content and migration of heavy metals in commercially available stainless steel electric kettles using efficient detection technologies. Methods In this study, 20 batches of stainless steel electric kettle samples were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS) to determine the migration levels of 13 kinds of heavy metal elements, along with label compliance checks. A handheld X-ray fluorescence (XRF) spectrometer was employed to rapidly detect the elemental content of key components and analyze their material composition. Results Multi-element migration experiments revealed heavy metal migration in some samples, particularly manganese (Mn) and aluminum (Al). XRF analysis identified the use of non-food-grade stainless steel in certain products. Additionally, non-compliant product labeling and discrepancies between labeled and actual material compositions were observed in some samples. Conclusion The combined ICP-MS and XRF results demonstrat that stainless steel material quality is a critical factor influencing heavy metal migration. This study provides theory basis for enhancing industry quality regulation, ensuring consumer health and safety, and promoting technological advancements in product manufacturing.

Objective To explore the distribution of metal elements in honeycomb and the potential food safety risks. Methods In this study, flame atomic absorption spectrometry was used to determine the content of Cd, Fe, Cr, Mg, Zn, Cu, Mn and Pb in 7 parts (nest membrane, nest column, nest wall, whole nest, adult bee, nest bottom, pupae) of honeycomb samples collected from Yunnan, Guangdong and Guangxi. Results The standard curves exhibited excellent linearity with correlation coefficients (r²)≥0.993, and the method sensitivity met trace detection requirements (limits of detection: 0.002-0.010 mg/kg). Significant differences in metal content was observed among different parts of the honeycombs (P<0.05), with the average concentrations ranked as Mg (0.97 mg/kg)> Zn (0.15 mg/kg)>Mn (0.051 mg/kg)>Cu (0.0385 mg/kg)>Fe (0.02 mg/kg) >Cd (0.0060 mg/kg)>Pb (0.00027 mg/kg)> Cr (0.00003 mg/kg). The distributions of Cd, Fe, Mg, Zn, Cu and Mn showed significant variations across parts (P<0.05), whereas Cr and Pb exhibited no significant differences (P>0.05). The results suggestted that the distribution of essential elements (Mg and Zn) was closely associated with the biological functions of honeycombs, while the localized accumulation of Cd and Pb might reflect environmental contamination. Conclusion This study systematically reveals the spatial distribution characteristics of metal elements in honeycombs, providing a scientific foundation for quality control of bee products and traceability of environmental pollutants.

Objective To investigate the residual characteristics of neonicotinoids pesticides in vegetables and the dietary exposure risk of residents in Hubei Province from 2022 to 2023. Methods A total of 887 vegetable samples were collected from 17 cities in Hubei Province, and neonicotinoid pesticide residues were determined. Dietary exposure was assessed according to the vegetable consumption of residents in Hubei Province. Results The overall detection rate of neonicotinoids in vegetables in Hubei Province was 33.4%, and the exceeding standard rate was 1.58%. The top 3 neonicotinoids exceeding the standard rate were clothianide (1.01%), acetamidine (0.23%) and imidacloprid (0.23%). The top 3 vegetable varieties exceeding the standard rate were fresh beans (6.06%), roots and tubers (4.48%), and melon vegetables (2.00%). The results of dietary exposure assessment showed that the chronic exposure hazard quotient of different neonicotinoids in Hubei Province was less than 1, the chronic exposure risk was low. The cumulative exposure of 8 kinds of neonicotinoids accounts for 2.78% of the acceptable daily intake of the indicator compound imidacloprid, indicating a low cumulative exposure risk. Conclusion The chronic exposure risk of neonicotinoid pesticides through vegetables for residents in Hubei Province from 2022 to 2023 is relatively low. However, there are cases of neonicotinoid pesticide residues exceeding the standard in vegetables, and the types of vegetables with excessive residues are different from those of traditional pesticides. It is suggested that relevant regulatory authorities further strengthen the supervision of neonicotinoid pesticides in fresh beans, root and tuber vegetables, and gourd vegetables.

Objective To screen a strain that can antagonize the growth of Aspergillus flavus and to identify the strain, study its application and analysis its genetic preliminarily. Methods The microorganisms in the soil of peanut field in Feixian County were used as the research object, and the effective strains were obtained through the screening of Aspergillus flavus standoff test; the effective strains species were determined through morphological observation and 16S rRNA gene analysis and identification; the peanut pods and peanut kernels were infested with the suspension of Aspergillus flavus spores to validate the effective bacteria’s effect of antagonizing the growth of Aspergillus flavus; and the genome characteristics of the bacterial strains and the clusters of genes of secondary metabolites synthesis were analyzed to determine the basic characteristics of the effective bacterial strains. The genomic characteristics of the strain and the secondary metabolite synthesis gene cluster were analyzed to determine the basic characteristics of the effective strain. Results Effective strain G22, which could antagonize the growth of Aspergillus flavus, was obtained by screening. The strain G22 was identified as Burkholderia latens with 99.93% homology and named Burkholderia latens G22 by morphological characterization and gene homology analysis. The fermentation broth of the effective strain had a certain antagonistic effect on the growth of Aspergillus flavus on peanut pods and peanut seed kernels. The genome of the effective strain had 3 chromosomes and 1 plasmid, and the secondary metabolite synthesis gene cluster proved that the effective strain had antagonistic properties. Conclusion Strain G22 has good antagonistic effect on the growth of Aspergillus flavus. The application effect of strain G22 in peanut has important research significance in practice, which will lay a foundation for the further development of microbial fungicides for Aspergillus flavus.