Objective To investigate the effects of 3 kinds of different thermal processing methods on the quality of Triticum aestivum L. germ. Methods Fresh Triticum aestivum L. germ was used as the test material, and dry heat, microwave and moist heat methods were used to treat Triticum aestivum L. germ to analyze the effects of different thermal processing methods on the nutritional quality and oil quality of Triticum aestivum L. germ. Results There were no significant differences (P>0.05) in fatty acid composition among 3 kinds of thermal processing methods, and ash, fat, protein and mineral contents on a dry basis were essentially unchanged. Compared with fresh Triticum aestivum L. germ, dry heat and microwave methods decreased water content, vitamin E content (dry basis) and amino acid content (dry basis); moist heat method increased in water content, decreased in vitamin E content (dry basis) and no significant difference (P>0.05) in amino acid content (dry basis) content. Acid value and free fatty acid content increased and peroxide content decreased in the dry heat method; the acid value and free fatty acid content of microwave method and moist heat method were significantly reduced (P<0.05), the content of peroxide value significantly increased (P<0.05). Conclusion Moist heat method helps to protect the quality of Triticum aestivum L., can better improve the storage stability of Triticum aestivum L. germ, and provides a basis for further high-value processing and utilization of Triticum aestivum L. germ and the development of functional components.

Currently, widespread concerns have been raised regarding food contamination caused by the migration of photoinitiators in food packaging materials. This article presented a review of the research on different volatile photoinitiators and their applications as standard substances both domestically and internationally. Based on the research focus, several compounds were selected as representatives of highly volatile and less volatile photoinitiators, including benzophenone (BP), 4-methylbenzophenone (4-MBP), ethyl 4-(dimethylamino)benzoate (EDB), 1-hydroxycyclohexyl phenyl ketone (PI-184), methyl-o-benzoylbenzoate (OMBB), 2,2-dimethoxy-2- phenylacetophenone (PI-651), 2-ethylhexyl-4-(dimethylamino)benzoate (EHA) and 2-isopropylthioxanthone (2-ITX). This paper summarized the mechanisms of photoinitiators migration and contamination, discussed analytical detection methods, compared the types of sample matrices used in the contamination and migration studies of different volatile photoinitiators both domestically and internationally, also analyzed the proportion of standard substances used in domestic and international research, their sources, and the demand for new standard substances. It was found that the current national standard substance resource sharing platform provides the most extensive collection of BP and ITX standard substances for photoinitiators research; however, it was recommended that other widely discussed photoinitiators, such as EDB, PI-651, PI-184 and OMBB, be included in new planning. Suggestions for the development of standard substances for photoinitiators in China were provided in this article, offering broader technical support for the study of photoinitiators contamination in the country.

Objective To establish an analytical method for the determination of selenium content in beef and offal (beef heart, beef liver, beef lung) using microwave digestion-hydride atomic fluorescence spectrometry (HG-AFS). Methods Based on 2 factors, namely the feeding amount and feeding time of the cattle, 80 simmental bulls weighing around 500 kg (±10 kg) were selected and randomly divided into 4 groups: A, B, C and D. Groups A, B and C served as experimental groups, while group D was the control group, with 20 cattle in each group. Selenium in beef and offal samples was digested using a nitric acid-hydrogen peroxide (HNO₃-H₂O₂) microwave digestion method, with potassium borohydride as the reducing agent and 10% hydrochloric acid as the carrier stream, at a digestion temperature of 190 ℃. Results Selenium exhibited a good linear relationship within the mass concentration range of 0-20 ng/mL, with a correlation coefficient (r)>0.999. The average spike recovery rates (n=3) for samples A, B, C and D were 86.9%, 82.4%, 87.9% and 83.8%, respectively. Conclusion This study provides data support and a reference basis for the determination of selenium content in selenium-enriched cattle products and the development of selenium-enriched functional agriculture.

Objective To improve the storage stability of Laian Malus asiatica cloudy juice beverage. Methods Using suspension stability as the main indicator, the effects of stabilizer composition, ultrasound, and homogenization assisted treatment on the stability of fruit juice beverages were analyzed. Through storage experiments, the changes in quality indicators of cloudy juice at 4 ℃ and 25 ℃ were analyzed, and a model was constructed to predict its shelf life. Results The stabilization process of Laian Malus asiatica cloudy juice was as follows: 0.05 g of xanthan gum and 0.1 g of sodium carboxymethyl cellulose were added to every 100 mL of cloudy juice, assisted by ultrasonic treatment at 300 W for 0.5 min, and then homogenized at 10000 r/min for 1.0 min. Under these conditions, the suspension stability of fruit juice beverages increased from 12.21% to 38.62%. The storage test showed that at 4 ℃, 25 ℃, and 90 d of storage, the largest change was in comprehensive color difference value (∆E), followed by total acid, while the smaller changes were in suspension stability and sensory perception. It was found that there was a highly significant correlation (P<0.001) between 4 quality indicators, including ∆E, total acid conetent, suspension stability, and sensory evaluation. The model fitting results showed that the changes in quality indicators of fruit juice beverages during storage conform to a first-order kinetic model. According to the sensory evaluation model, the predicted shelf life of beverages at 4 ℃ and 25 ℃ was 384.36 d and 153.74 d, respectively. The verification test results showed that the relative error between the predicted storage time of the model and the actual time at 4 ℃ and 25 ℃ was very low, only 4.50% and 0.82%, respectively. Conclusion The stability of Laian Malus asiatica cloudy juice beverage can be significantly improved by xanthan gum and sodium carboxymethyl cellulose, assisted with ultrasound and homogenization treatment. The established model has high accuracy and can be used for predicting the shelf life of juice beverages.

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 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 elucidate the effects of different cooling rates after purification on the volatile flavor compounds of anhydrous live Crassostrea gigas. Methods This study employed gas chromatography-ion mobility spectrometry (GC-IMS) to analyze the volatile flavor compounds of oysters that were purified for 24 hours and then cooled to 4 °C at varying rates (1, 3, 7, 11 and 16 °C/h). Results The results indicated that 45 kinds of known compounds were detected via GC-IMS, with 5 kinds of compounds identified in their dimeric forms. These compounds included 10 kinds of alcohols, 8 kinds of aldehydes, 6 kinds of esters, 7 kinds of ketones, 4 kinds of hydrocarbons, 3 kinds of furans, 3 kinds of alkenes, and 4 kinds of other compounds. Propanal and isovaleraldehyde levels decreased with increasing cooling rates, while acetone levels increased significantly. A total of 25 kinds of differential flavor compounds, including propionaldehyde, n-butanal, 2-butanone and acetone, were selected based on variable importance in the projection, and these compounds might serve as potential biomarkers for distinguishing oysters during the distribution process. Conclusion This study demonstrates that different cooling rates after purification have a significant impact on Crassostrea gigas in anhydrous preservation, providing theoretical support for the preservation and freshness maintenance of Crassostrea gigas.

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 rapid competitive inhibition immunochromatographic detection method for the simultaneous determination of 3 kinds of neonicotinoid pesticides with a high non-compliance rate in Musa nana Lour.. Methods The samples were extracted using a solution composed of 20% methanol, 0.05% Tween, and 0.02 mol/L phosphate-buffered saline (PBS). After centrifugation at 8000 r/min for 5 min, 100 μL of the supernatant was taken and diluted according to specific dilution ratios. Subsequently, 100 μL of the diluted sample solution was added to the sample well (S). The results were read after 8 min reaction period. Results The limits of detection for imidacloprid, clothianidin, and thiamethoxam were 0.050, 0.020 and 0.002 mg/kg, respectively, with corresponding sample dilution factors of 2-fold, no dilution, and 5-fold. Upon evaluation, the relative accuracies were determined to be 96.7%, 98.3% and 100.0%, respectively, which were in agreement with the results obtained by the liquid chromatography-mass spectrometry method for the detection of these pesticides in Musa nana Lour.. Conclusion This rapid detection method exhibits characteristics such as simplicity in operation, rapidity in detection, and portability of the instrument, rendering it suitable for on-site and rapid screening of pesticide residues in Musa nana Lour..

Objective To prepare a multifunctional chitosan-based composite film and improve its application in fruit preservation. Methods A kind of chitosan/lignin/ε-polylysine composite film was fabricated, and its effects on the postharvest preservation of Citrus reticulate ‘Shiyue Ju’ and Vaccinium spp. were also investigated. Results The results showed that although the addition of lignin made the film brown, the good transparency, excellent water resistance and antioxidant property were also observed in the obtained film. Moreover, the results showed that the composite film loaded with 0.2% ε-polylysine exhibited 100% inhibition rate against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coil). The preservation experiment results indicated that, under the optimized film composition conditions (2.0% chitosan, 0.023% lignin, 0.2% ε-polylysine), the chitosan/lignin/ε-polylysine composite film could effectively delay the changes of physical and chemical properties during the fruits storage. After 12 days of storage at room temperature, compared with the blank groups (untreated Citrus reticulate ‘Shiyue Ju’ and Vaccinium spp.), the composite film-treated Citrus reticulate ‘Shiyue Ju’ and Vaccinium spp.’s rot rate decreased by 22.22% and 62.50%, the weight loss rate decreased by 3.22% and 3.67%, as well as the hardness of Citrus reticulate ‘Shiyue Ju’ increased by 35.59% and the hardness of Vaccinium spp. increased by 2.02%, respectively. At the same time, the composite film effectively maintained the content of soluble solids, vitamin C (VC), titratable acid and other nutrients in Citrus reticulate ‘Shiyue Ju’ and Vaccinium spp.. Conclusion The prepared chitosan/lignin/ε-polylysine composite film is expected to replace chemical preservatives in the preservation of oranges and blueberries, providing a reference for the development of novel green preservation materials.