Objective To investigate the effects of Bacillus natto fermentation on the quality characteristics and storage stability of Arachis hypogaea L. natto produced from red Arachis hypogaea L.. Methods A novel Arachis hypogaea L. product, Arachis hypogaea L. natto, was prepared through fermentation using Bacillus natto, and its quality characteristics and storage stability were systematically evaluated. In this study, the protein content, fat content and flavor compounds of Arachis hypogaea L. natto were determined. Sensory scores and L^* were monitored during the storage period. Additionally, the levels of total volatile basic nitrogen (TVB-N), amino acid nitrogen and a^* were assessed. Results The results indicated that compared with unfermented Arachis hypogaea L., the protein content of Arachis hypogaea L. natto decreased to 25.84%, and the fat content reduced to 17.72%. Fermentation promoted the production of alcohol and aromatic compounds, resulting in distinct flavor profiles characterized by sourness, saltiness, umami and bitterness. During fermentation, lipolysis produced linoleic acid, leading to a reduction in fat content. Moreover, some free water became less mobile, transitioning into weakly bound water. Over time, the sensory score and L^* and b^* of Arachis hypogaea L. natto declined, whereas the levels of TVB-N, amino acid nitrogen increased. Conclusion Bacillus natto fermentation significantly alters the nutritional composition and flavor characteristics of Arachis hypogaea L. natto. sensory quality deteriorates during storage. These findings provide a theoretical foundation for utilizing Bacillus natto in Arachis hypogaea L. fermentation and offer new insights into developing innovative Arachis hypogaea L. products.

Objective To investigate the effects of low-temperature fermentation processes and fermentation duration on the aroma composition and aromatic characteristics of summer-harvested Jingshan black tea. Methods First, headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) combined with sensory evaluation was used to analyze the aroma components of 12 samples fermented at 3 temperatures (25, 28 and 35 ℃) and four durations (2.5, 4.0, 5.5 and 7.0 h). Second, principal component analysis (PCA) and hierarchical cluster analysis (HCA) were employed to explore the differences among samples under varying fermentation conditions (temperature and duration). Finally, Orthogonal partial least squares-discriminant analysis (OPLS-DA) with variable importance projection (VIP) scores and relative odorant activity value (OAV) was conducted to screen differential volatile compounds related to fermentation conditions. Results A total of 86 kinds of aroma components were analyzed and identified by the above-mentioned methods. Among them, 15 kinds of substances, such as dimethyl sulfide, linalool, (E,E)-2,4-heptadienal, indole and geraniol, were identified as the key differential volatile compounds under different fermentation conditions (temperature and time). Compared with other fermentation time samples, 4.0 h samples had higher concentration of volatile compounds and better quality. Among the samples with a 4.0 h fermentation duration, the samples fermented at 25 ℃ and 28 ℃ obtained higher sensory scores and presented distinct aroma profiles. At this duration, 25 ℃ and 4.0 h-fermented samples displayed floral aromas dominated by dimethyl sulfide, dehydro-linalool, linalool and neral, while 28 ℃ and 4.0 h-fermented samples exhibited fruity notes characterized by myrcene, citral and geraniol. Conclusion Low-temperature fermentation processes and fermentation duration critically influence the aromatic quality of Jingshan black tea.

Objective To develop a compound beverage suitable for diabetics using Auricularia auricula and Stigma maydis as raw materials. Methods Using Auricularia auricular and Stigma maydis as raw materials, xanthan gum as a stabilizer, and mogroside as a flavoring agent, the preparation process of the compound beverage was optimized through orthogonal experiments. The hypoglycemic effects of the beverage was evaluated by in vitro hypoglycemic and antioxidant tests. Results The optimal formula for the compound beverage was as follows: 30% of Auricularia auricula enzymatic hydrolysate, 40% of Stigma maydis extract, 0.10 g of mogroside, and 0.03 g of xanthan gum. Under these conditions, the sensory score of the compound beverage was 73.57 points. The α-glucosidase inhibition rate and α-amylase inhibition rate of the composite beverage were (55.26±2.05)% and (34.64±0.40)%, respectively. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging rate, superoxide anion scavenging rate, and hydroxyl radical scavenging rate of the compound beverage were (77.08±1.20)%, (30.56±0.41)%, and (38.95±0.43)%, respectively, all superior to those of the single Auricularia auricula enzymatic hydrolysate and Stigma maydis extract. Conclusion The composite beverage demonstrates positive effects in regulating blood glucose levels and eliminating endogenous free radicals. This study establishes the optimized formulation and preparation process for Auricularia auricula and Stigma maydis compound beverage, which demonstrates both feasibility and effectiveness. These findings provide both a theoretical foundation and practical references for developing functional beverages with dual hypoglycemic and antioxidant properties.

Objective To develop a rapid method for the determination of nitrofuran metabolites in aquatic products based on chitosan purification combined with ultra performance liquid chromatography and triple quadrupole/composite linear ion trap mass spectrometer. Methods The samples were hydrolyzed by hydrochloric acid, derived by 2-nitrobenzaldehyde, extracted by ethyl acetate, rapidly purified by chitosan, and then concentrated and redissolved. Rapid separation was achieved by ultra performance liquid chromatography, measured by triple quadrupole/composite linear ion trap mass spectrometer, and quantified by internal standard method to achieve the rapid and accurate determination of nitrofuran metabolites residues in aquatic products. Results The 4 kinds of nitrofuran metabolites had a good linear relationship in the concentration range of 0.5-10.0 μg/L, the correlation coefficients were all more than 0.998, and the limit of quantification was 0.5 μg/kg. Taking carp, Scophthalmus maximus and Litopenaeus vannamei as samples, the average recovery of 4 kinds of nitrofuran metabolites at 3 different addition levels was 96.5%-116.5%, the intra-day relative standard deviation was 2.2%-9.3%, and the intra-day relative standard deviation was 2.7%-9.7%. Conclusion The method is economical, simple, efficient, sensitive and reproducible, and can be used as a routine method for the determination of 4 kinds of nitrofuran metabolites in aquatic products.

Objective To evaluate the diazepam rapid detection products of 5 manufacturers with high recognition in Beijing. Methods In this study, common carp, grass carp and crucian carp were used as the substrate for technical evaluation from the aspects of sensitivity, HOOK effect, specificity, accuracy and ease of operation, etc. The evaluation results were referred to the Notice on the field verification of rapid detection products for drug residues in aquatic products in 2023 issued by the Chinese Academy of Fishery Sciences. Results The limits of detection for sensitivity of company I-V were 92.2%, 88.9%, 100.0%, 65.6% and 33.3%, respectively. Company II HOOK effect false negative 10%; HOOK effect did not appear in the other 4 companies. The cross-reaction rate of company III to the residues of 4 kinds of common veterinary drugs was as high as 60% to 90%, the cross-reaction rate of company II to enrofloxacin was 10%, the cross-reaction rate of company V to enrofloxacin and oxytetracycline were 10.0% and 20.0%. The other 2 companies did not have cross-reaction. The overall accuracy of all samples ranged from 79.2% to 96.9%. Company I had the highest overall accuracy (96.9%) and company V had the lowest accuracy (79.2%). The average test time of 24 samples is between 57 and 82 min, which meet the requirements of rapid detection technology. The rapid detection of diazepam in aquatic products of company I was qualified. The evaluation of company II-V was not qualified. At present, the performance of diazepam rapid detection products in aquatic products sold in Beijing was still a certain gap with the national legal confirmation method, which needed to be further improved. Conclusion This study is expected to provide reference for the purchase and application of grassroots supervision staff, and promote the application of rapid detection technology in the supervision of aquatic product quality and safety.

Objective To investigate the quality characteristics of wild Rosa roxbunghii seeds polysaccharides from different regions in Guizhou Province. Methods Wild Rosa roxbunghii seed polysaccharides were extracted from 11 different regions in Guizhou Province by ultrasonic assisted enzymatic method, and the physicochemical properties of the polysaccharides were determined to compare their differences. Results The composition, physicochemical properties, antioxidant properties and application quality of wild Rosa roxbunghii seed polysaccharides from different regions in Guizhou Province were not the same. In terms of physical and chemical properties, the extraction ratio of wild Rosa roxbunghii seed polysaccharides in region QD3 was the highest (26.23%); the solubility of wild Rosa roxbunghii seed polysaccharides in region QD5 was the best (98%); the holding oil capacity of wild Rosa roxbunghii seed polysaccharides in region QD9 was the highest (5.06 g/g) and the content of galacturonic acid was the highest (55.90%); the content of protein in wild Rosa roxbunghii seed polysaccharides in region QD7 was the highest (18.53%); and the content of neutral sugar in wild Rosa roxbunghii seed polysaccharides in region QD10 was the highest (15.04%). In terms of in vitro antioxidant activity, the wild Rosa roxbunghii seed polysaccharide from region QD3 had the strongest 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cationic radical scavenging ability [half maximal inhibitory concentration (IC₅₀) value=0.09 mg/mL]; the wild Rosa roxbunghii seed polysaccharide from region QD10 had the strongest hydroxyl radical scavenging ability (IC₅₀ value=0.24 mg/mL); and the wild Rosa roxbunghii seed polysaccharide from region QD2 had the strongest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability (IC₅₀ value=0.13 mg/mL). In terms of application quality, the hardness of the cookie formula with wild Rosa roxbunghii seed polysaccharides from region QD4 was the largest; and the crispiness of the cookie formula with wild Rosa roxbunghii seed polysaccharides from region QD1 was the best. Conclusion The quality of wild Rosa roxbunghii seed polysaccharides from different regions in Guizhou Province is obviously different and has its own characteristics. The results of this study can provide a theoretical basis for developing functional products from wild Rosa roxbunghii seed polysaccharides, broadening the way of deep processing and utilization of wild Rosa roxbunghii fruit, improving the economic benefits of wild Rosa roxbunghii fruit, and providing data reference for the development of related industries and scientific research.

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.

As the cornerstone of the global food system, wheat flour, a derivative product of limited wheat in various countries, is not only an important component of human daily diet, but also a key element in maintaining global food security. However, in recent years, the frequent contamination of fungal toxins in wheat flour has become a major challenge in the field of food safety, posing a significant threat to food safety and human health. The main types of fungal toxins in wheat flour include deoxynivalenol, aflatoxin, zearalenone, etc. The contamination of deoxynivalenol is the most prominent, but there are certain differences in the relevant limit standards at home and abroad. This study aimed to comprehensively review the types and contamination status of major fungal toxins in wheat flour. By comparing relevant limit standards at home and abroad, it could be found that different countries and regions had different assessment and management strategies for food safety risks. Based on the analysis and discussion of the above content, a comprehensive prevention and control strategy is proposed, aiming to provide scientific guidance and technical support for the safe production, processing, and consumption of wheat flour.

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.