Objective To establish a method for determination of 7 kinds of antioxidant residues, including tert-butylhydroquinone, 2,6-di-tert-butyl-4-methylphenol, butylated hydroxyanisole, butylated hydroxytoluene, 3,5-di-tert-butylphenol, 2,4-di-tert-butylphenol, and 2,6-di-tert-butylphenol, in edible oils by QuEChERS combined with gas chromatography-tandem triple quadrupole mass spectrometry. Methods Edible oil samples were extracted with acetonitrile, and the supernatant was purified using the QuEChERS method, followed by filtration through an organic membrane for direct analysis. Separation was achieved using a HP-5MS chromatographic column, and quantification was performed using the external standard method under electron ionization and multiple reaction monitoring modes. Results The method effectively distinguished the 7 kinds of antioxidants, including their corresponding isomers. The target compounds exhibited good linearity and peak shapes within the range of 1-300 µg/L (r²≥0.99). The limits of detection ranged from 0.11 to 2.77 µg/kg, and the limits of quantification ranged from 0.36 to 9.23 µg/kg. The spiked recovery rates ranged from 72.51% to 116.33%, with relative standard deviations of 0.36% to 5.82% (n=8). Among the actual samples, 2,4-di-tert-butylphenol had a relatively high detection rate. Conclusion This method is simple, accurate, and capable of effectively distinguishing tert-butylphenol antioxidants, making it suitable for high-throughput detection of multiple antioxidants in edible oils.

Objective To optimize a compound desulfurizer of pickled pepper raw material by principal component analysis and response surface method. Methods The limit of detection was based on GB 2760—2014 National standard for food safety-Standards for the use of food additives, selected 3 kinds of desulfurizers with good desulfurization effect and little influences on raw material quality from 9 kinds of common desulfurizers by single factor experiments, designed a 3-factor, 3-level experiment by response surface method, through principal component analysis and response surface analysis, the optimum compound ratio and the optimum operating conditions were obtained. Results When the mass fraction of calcium hydroxide was 44.05%, sodium bicarbonate was 35.57%, chlorine dioxide was 20.38%, and the concentration was 0.10%, the desulfurization rate could reach 94.55%, which was about 36.50% higher than that of no use. At the same time, the color and hardness of pickled pepper materials had no obvious changes. Conclusion The study obtains a kind of compound desulfurizer with good desulfurization effect and little influences on raw material quality, and has high application value.

Objective To investigate the generation pattern of heterocyclic amines (HAs) and advanced glycation end products (AGEs) in plant hamburger meat under different thermal processing conditions. Methods ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to analysed the effects of different treatments (uncooked, steamed and grilled), grilling temperatures (160, 180, 200 °C), and grilling times (4, 8, 12 min) on the content of free HAs and AGEs, bound HAs and AGEs, and amino acids in the plant hamburger meat. AGEs and amino acid content of plant hamburger meat, and investigate the simultaneous generation of free and bound HAs and AGEs in plant hamburger meat under different thermal processing conditions using principal component analysis (PCA). Results The results of PCA showed that the highest levels of free HAs and AGEs and bound HAs were found in plant hamburger meat under 200 °C/12 min roasting condition in the roasted sample group. A total of (11.44±2.68) ng/g of total free HAs, (80.24±9.56) ng/g of total bound HAs, (1.99±0.29) μg/g of total free AGEs and (46.00±4.00) μg/g of total bound AGEs were detected in the raw hamburger meat. Compared with raw plant hamburger meat, there was an increase in bound N^ε-carboxyethyl-lysine (CELs) and a smaller difference in free AGEs and HAs in steamed plant hamburger meat. There was a significant increase in hazardous material content after steaming and roasting (200 °C, 12 min), which increased by 191.83%, 164.38%, 218.59% and 15.70%, respectively, as compared to the blank group. During roasting, the free and bound HAs, free AGEs in plant hamburger meat showed a increase with the increase of roasting temperature and time. The total amount of free and bound HAs and free AGEs increased by 79.14%, 23.38% and 88.05%, respectively, under the conditions of roasting temperature of 180 °C and roasting time of 4-12 min; under the condition of roasting time of 8 min, the content of hazards in plant hamburger meat at roasting temperature of 200 °C compared with that at 160 °C increased by 61.28%, 34.82% and 67.93%, respectively. Conclusion Different treatments and thermal processing conditions has significant effects on the generation of HAs and AGEs, which increase with the increase of roasting temperature and the prolongation of roasting time in plant hamburger meat. This study aims to provide theoretical and experimental basis for the reduction and control of HAs and AGEs in thermal processing of plant hamburger meat.

Objective To study the distribution characteristics and health risk exposure levels of 6 kinds of common quinolone antibiotics in poultry eggs and chicken meat in Inner Mongolia. Methods The content of norfloxacin, enrofloxacin, ofloxacin, pefloxacin, ciprofloxacin and lomefloxacin in poultry eggs and chicken samples randomly collected from some cities in the region. In 2021, 2022 and 2024 were determined by isotope internal standard, solid phase extraction, ultra performance liquid chromatography-tandem mass spectrometry, the data of quinolone residues in poultry eggs and chicken in the whole region were statistically analyzed, according to the reference value of different age groups dietary intake and detected data, the hazard quotient of each age group was calculated and the health risk to the population was analyzed. Results In 2021, the detection rate of poultry eggs was 5.00% (3/60), the exposure levels was 0.09-0.52 μg/(kg·d), and the hazard quotient was 0.004-0.021; the detection rate of chicken was 16.70% (10/60), the exposure levels was 0.23-12.39 μg/(kg·d), and the hazard quotient was 0.009-0.492. In 2022, the detection rate of poultry eggs was 6.25% (5/80), the exposure levels was 0.09-0.49 μg/(kg·d), and the hazard quotient was 0.004-0.019; the detection rate of of chicken was 3.75% (3/80), the exposure levels was 0.01-0.68 μg/(kg·d), and the hazard quotient was 0.0004-0.0270. In 2024, the detection rate of poultry eggs was 3.33% (4/120), the exposure levels was 0.13-0.70 μg/(kg·d), and the hazard quotient was 0.005-0.028; the detection rate of chicken was 6.36% (7/110), the exposure levels was 0.03-1.58 μg/(kg·d), and the hazard quotient was 0.001-0.063. Conclusion The 3 years of analysis data shows that quinolone antibiotics are detected in poultry eggs or chicken almost all cities, the average detected in chicken is higher than that in poultry eggs. The exposure risk of quinolone antibiotics in poultry eggs and chicken in 4 age groups is less than 1 and the health risk is small.

Objective To establish a method for qualitative determination of Tricholoma matsutake ingredients by a TaqMan real-time fluorescence polymerase chain reaction (PCR), and identify the conformity of Tricholoma matsutake and its products with their labels by DNA barcoding technology. Methods Taking the pol gene of Tricholoma matsutake as the target gene, specific primers and probes were designed to study and analyze their specificity, sensitivity and repeatability. The established TaqMan real-time PCR method of Tricholoma matsutake was used to detect different types of commercially available samples and identify their authenticity. Results The established method was used for real-time PCR detection, and there was no cross-reactivity between Tricholoma matsutake and 32 kinds of other edible fungi, animals and plants, indicading strong specificity of the method. The sensitivity was 0.01% Tricholoma matsutake and 0.01 ng/μL Tricholoma matsutake genomic DNA. The authenticity test of 160 commercially available Tricholoma matsutake and their products showed that there was counterfeiting of dried Tricholoma matsutake. The test results did not match the labels at a rate of 36.70%. DNA barcoding technology was used to further identify the species of counterfeit matsutake mushrooms, with species attributes of Stropharia rugosoannulata, Tricholoma giganteum and Tricholoma bakamatsutake. The non-compliance rates with labels in the authenticity testing resultes of other collected matsutake products were 23.70%-60.00%, respectively. Conclusion This method has high sensitivity and strong specificity, which can quickly and accurately identify the authenticity and compliance of Tricholoma matsutake ingredients.

Objective To understand the prevalence, serotype distribution and drug resistance of Salmonella from foodborne diseases in Fengtai District, Beijing from 2016 to 2023. Methods Salmonella was isolated and identified from the stool samples of foodborne diseases. Serotypes of Salmonella were identified by slide agglutination test. The antimicrobial resistance of Salmonella was determined by micro broth dilution method and minimum inhibitory concentration method. Results The detection rate of Salmonella was 4.33%, which increased from 2.11% to 9.28% from 2016 to 2023. Salmonella infection peaked in autumn. The detection rate of Salmonella was higher in people aged 0-9 old years and 40-49 old years, and people of fever, nausea and diarrhea more than 6. The consumption of meat and meat products was the risk factor of Salmonella infection. The top 5 serotypes were Salmonella enteritidis, Salmonella typhimurium, Salmonella thompson, Monophasic salmonella enterica serovar typhimurium and Salmonella senftenberg. There was an upward trend in the detection rate of Salmonella thompson, and Monophasic salmonella enterica serovar typhimurium. The resistance rate of Salmonella to nalidixic acid (NAL), ampicillin (AMP) and ampicillin-sulbactam (AMS) was higher, the intermediate rate of Salmonella to ciprofloxacin (CIP) was higher, and the sensitivity of Salmonella to gentamicin (GEN), imipenem (IMI) and azithromycin (AZI) was higher. The drug resistance of Salmonella enteritidis was the most serious, the drug resistance rate of tetracycline (TET) and ceftazidime (CAZ) was increasing, and the intermediate rate of CIP was decreasing. The multi-drug resistance rate of Salmonella was 44.00%, which included 31 drug resistance profiles. Conclusion The detection rates of Salmonella are different in different age, different symptoms and food exposure history of people, and different season. Salmonella enteritidis is the main serotype. The serum distribution of Salmonella is dispersive. The resistances of Salmonella to quinolones antibiotics and β-lactam antibiotics are serious, and the situation of multi-drug resistance is serious. We should enhance food safety education on Salmonella, strengthen surveillance on meat food safety, strengthen surveillance on new salmonella species such as Monophasic salmonella enterica serovar typhimurium, strengthen the use of antibiotics, and optimize measures for disease prevention and control of Salmonella.

Objective To analyze the differences in mineral elements in wild rice from different regions and establish a method for tracing the origin of wild rice based on mineral element fingerprint characteristics. Methods Inductively coupled plasma mass spectrometry (ICP-MS) was used to analyze the content of 24 kinds of mineral elements in 40 wild rice samples from the United States, Canada, and China. The data were subjected to variance analysis, multiple analysis, principal component analysis, and discriminant analysis to explore the feasibility of using mineral element fingerprint characteristics for tracing the origin of wild rice. Results The content of 24 kinds of elements showed significant differences among the regions. Principal component analysis extracted 3 principal components, with a cumulative variance contribution rate of 93.1%. Principal component analysis successfully distinguished wild rice from the United States and Canada. Discriminant analysis correctly identified 97.7% of the wild rice samples. Conclusion This study demonstrates the feasibility and accuracy of classifying wild rice samples from different origins.

Objective To establish a qualitative and quantitative analytical method for determination of short-chain fatty acids in table salt using headspace solid phase microextraction arrow-gas chromatography-mass spectrometry. Methods A phosphoric acid solution was added to the salt samples, and the headspace solid phase microextraction arrow technique was employed to extract and enrich the short-chain fatty acids. The effects of extraction fiber, extraction temperature, extraction time, and incubation time on the extraction efficiency were investigated. The target compounds were detected by gas chromatography-mass spectrometry and quantified using the external standard method. Results The 100 μm Polyacrylate extraction fiber demonstrated good selectivity for short-chain fatty acids. Under optimal conditions (extraction temperature of 40 °C, extraction time of 30 min, desorption time of 5 min and incubation time of 20 min), the method showed excellent linearity for 9 kinds of short-chain fatty acids, with correlation coefficients greater than 0.995. The limits of detection ranged from 0.25 to 25.00 μg/kg, the recovery rates were between 92.2% and 100.1%, and the relative standard deviations ranged from 1.4% to 9.4%. Conclusion The established method for analyzing short-chain fatty acids in table salt is characterized by simple sample preparation, high sensitivity, good recovery rates and stability, making it suitable for the detection of short-chain fatty acids in table salt.

Objective To establish a chronoamperometry detection method for accurately determining the nitrite content in food. Methods Cobalt nanoparticles, graphene oxide, and polypyrrole were electrodeposited on the electrode surface to construct an electrochemical sensor for nitrite detecting. The detection conditions were optimized, and the linear range of chronocurrent method for nitrite detection was determined. After the specificity of the detection method was verified, the samples were tested using the optimized detection conditions. Results An electrochemical sensor for nitrite detection was prepared. The optimal potential for this method was 0.85 V, the optimal pH was 8.0, and the optimal deposition time was 300 s. The interfering substances dopamine, ascorbic acid and uric acid had little impact on the detection of nitrite, and the detection of samples found that the established method had high accuracy. Conclusion An electrochemical sensor for detecting nitrite is prepared, which has good stability and high accuracy, and is suitable for the determination of nitrite content food.

Objective To explore the optimal aging time for high-quality beef. Methods The longissimus dorsi muscle of Wokin black cattle was selected as the experimental material. The beef was aged in a chilling room at 4 °C for 12, 24, 48, 72, 96, and 120 hours. Comprehensive analyses were conducted on the beef’s moisture content, pressurized water loss rate, tenderness, inosinic acid, amino acids and fatty acids. Principal component analysis was performed on tenderness and flavor composition indicators under different aging times. Results The moisture content of beef showed no significant differences among different aging times (P>0.05). The pressurized water loss rate gradually increased with prolonged aging time, reaching its maximum value of (34.84±0.39)% at 120 hours. Tenderness gradually decreased, reaching its lowest value of (24.42±5.04) N at 120 hours. The inosinic acid content peaked at (185.2±10.3) mg/100 g after 72 hours of aging. Umami and sweet amino acids reached their highest levels at 96 hours, while bitter amino acids reached their lowest levels at 12 hours. The content of saturated fatty acids+monounsaturated fatty acids, Methyl stearate (C18:0), and methanol oleate (C18:1n9c) were highest at 120 hours. Principal component analysis and comprehensive factor scoring results indicated that the tenderness and volatile flavor compounds of beef aged for 96 hours scored significantly higher than those aged for other durations. This aging time was most conducive to the formation of volatile flavor compounds in beef. Conclusion Aging for 96 hours is beneficial for enhancing the tenderness and flavor of high-quality beef.