Objective To study and analyze the mycotoxins contamination status of Castanea mollissima in Huairou District during one year of cold storage. Methods Taking Castanea mollissima produced in Huairou District as the research object. Castanea mollissima samples of 5 varieties, including 3113, Huaijiu, Huaihuang, Yanhong, and Huahua were collected from the 4 highest yielding townships in Huairou District. They were stored in a cold storage for one year and sampled once a month. The content of 21 kinds of fungal toxins was determined by ultra performance liquid chromatography-mass spectrometry. Results During the storage period, a total of 11 fungal toxins were detected, including tentoxin, alternariol, tenuazonic acid, nivalenol, zearalenone, fumonisin B₁, fumonisin B₂, fumonisin B₃, alternariolmethylether, ochratoxin A, and sterigmatocystin. The detection rate and value of Alternaria toxins were relatively high. According to the analysis of sampling locations, the number of fungal toxins detected in the 4 townships increased from 66 to 79, with no significant difference or clear pattern. Based on the analysis of storage time, the number of fungal toxins detected in chestnuts showed an overall upward trend with the extension of storage time. The detection rate of fungal toxins was relatively low in the 1 to 6 months of storage, with 4-5 cases detected each month. By the 7th month, the detection of fungal toxins increased to 12 cases, and from the 9th month onwards, all 17 samples were detected. Conclusion The Castanea mollissima shall be consumed and processed less than 6 months of storage after harvest according to the perspective of mycotoxins contamination. The overall detection rate of fungal toxins shows a monthly upward trend. There is no regularity in the detection of fungal toxins in different chestnut planting areas and varieties, and there is co-contamination in Castanea mollissima samples during storage. Further analysis and research on the pollution risk of Alternaria toxins in chestnuts is needed.

Objective To explore the protective effects of Panax notoginseng fibrous root extract on alcoholic liver disease in mice. Methods A total of 50 male C57BL/6J mice were randomly divided into 5 groups of 10 mice each: The control group, the model group, the low dose group (67.5 mg/kg), the medium dose group (135.0 mg/kg) and the high dose group (270.0 mg/kg). The control group and the model group were gavaged with pure water, while the Panax notoginseng fibrous root extract groups were given with the corresponding concentrations of the test substance at 20 mL/kg. The Panax notoginseng fibrous root extract groups and model group were gavaged with 40% ethanol (10 mL/kg) 5 hours late for 14 days. The Panax notoginseng fibrous root extract groups and model group were fasted for 16 hours after the last gavage, then each was given 40% ethanol at 20 mL/kg. After weighing the fasting body weight of each group of mice, blood was collected from the abdominal aorta and the liver was removed and weighed. Finally, determined the biochemical indices of serum and liver, and the levels of interleukin-1β (IL-1β) and interleukin-6 (IL-6) in liver. Results Compared with the model group, the medium and high dose groups of the serum triglyceride (TG), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were significantly decreased (P<0.05 or P<0.01). But the superoxide dismutase (SOD), glutathione (GSH) and glutathione peroxidase (GSH-Px) in liver was significantly increased (P<0.05 or P<0.01), while the content of malondialdehyde (MDA) was extremely significantly decreased (P<0.01). The content of TG in liver of high dose group was lower than the model group (P<0.01), the difference was statistical significance. Besides, the levels of IL-1β of the low and high dose groups were significantly decreased compared with the model group (P<0.05 or P<0.01). Conclusion The Panax notoginseng fibrous root extract has a good protective effect on hepatic injury induced by alcohol in mice.

Objective To establish an on-site rapid detection system for the risk of deoxynivalenol (DON) contamination based on multienzyme isothermal rapid amplification (MIRA) technology. Methods Highly homologous sequences of Tri toxin-producing gene clusters from the major DON-producing Fusarium species (including Fusarium graminearum, Fusarium asiaticum, Fusarium pseudograminearum and Fusarium culmorum) in China were obtained through gene sequence query and comparison by the National Centre for Biotechnology Information (NCBI) of the United States of America. By designing specific fluorescent probes and screening primers, a MIRA detection method for DON-producing Fusarium was established, and an on-site rapid detection system was constructed by combining the rapid paper-based DNA extraction technique. Results The limit of detection of this assay system was 1.95×10¹ copies/μL for plasmid templates and 15 fg/μL for genomic DNA. The results of 27 positive wheat samples at the filling stage (spike) showed a highly significant correlation with those of the quantitative real-time polymerase chain reaction (qPCR) method (r=0.820, P=0.000). When the MIRA detection threshold line was set at the 43rd scan point (peak onset time of 7 min), the combined discrimination accuracy between high (DON>1000 μg/kg) and low (DON<1000 μg/kg) DON contamination risk for 89 wheat samples was 87.15%. Conclusion The detection system demonstrates speed, economy, practicality, and portability in terms of reagents and instrumentation, and is capable of effectively achieving the objective of rapid on-site detection. This will facilitate early warning of the risk of DON contamination in wheat production in the field, thereby guiding interventions to prevent or minimise losses.

Objective To establish a method for determination of 2 kinds of new carbadenafil analogue in tablet candies and solid beverages by high performance liquid chromatography. Methods The sample was extracted by methanol ultrasound, the extract was centrifuged, filtered through a microporous membrane, and analyzed by the high performance liquid chromatography. The separation was performed on a Waters Xbridge C₁₈ column (250 mm×4.6 mm, 5 μm) with gradient elution by using 20 mmol/L ammonium acetate aqueous solution and methanol as the mobile phase, and quantified by external standard method. Results The 2 kinds of new carbadenafil analogue demonstrated good linearity in the range of 0.5-100.0 μg/mL, with the correlation coefficient values (r²) being higher than 0.999. The limits of quantification were found to be 5 mg/kg. The recoveries at 3 spiked levels of 1, 2 and 10 times the limits of quantification in blank matrix were in the range of 87.32%-93.92%, with the relative standard deviations between 1.19%-4.08%. A total of 8 batches of positive samples were detected using this method, with a content range of 218-2170 mg/kg. Conclusion The method is convenient, accurate and efficient. It can meet the identification requirement of illegally added 2 kinds of new carbadenafil analogue in tablet candies and solid beverages, and provide effective technical support to combat the illegal addition of new carbadenafil analogue in food.

Theaflavins (TF) are water-soluble pigments in tea. They possess rich biological activities such as antioxidant, antibacterial, alleviating metabolic syndrome, anti-inflammatory, tooth-protecting, neuroprotective, and antidepressant effects, and thus have broad application prospects. Given the complex structure, unstable chemical properties, low extraction efficiency, and the difficulty in obtaining TF, the oxidative preparation of TF has attracted significant attention. Oxidation preparation methods of TF include the chemical method and the enzymatic method. Chemical method utilizes a chemical oxidant. It features a uniform oxidation degree and strong controllability, and generates more ester TF in an acidic environment. However, the chemical oxidation method has poor specificity. Consequently, it is necessary to protect the hydroxyl group on the catechin A-ring to enhance the yield of TF. Moreover, the amount of oxidant required is large, and safety is a concern. In enzymatic preparation, polyphenol oxidase and peroxidase are employed. The conditions are mild, efficient, and specific. Efficiency of enzymatically preparing TF is influenced by the sources and types of oxidases, substrate composition, and reaction parameters. Yield of TF can be increased by preferentially oxidizing the oxidases of catechol catechins, increasing the proportion of biphenyl catechins, and reacting for an extended period in a weak-acid and low-temperature environment. Nevertheless, the current preparation methods still face problems such as a low extraction rate and low product purity. This paper discussed 2 kinds of oxidation preparation methods, and summarized their biological activities, in order to provide reference for the industrial production and application research of TF.

Objective To detect aflatoxin B₁ (AFB₁) in peanut oil by laser induced fluorescence and explore the effects of temperature on the detection results. Methods The spectral information of AFB₁ contaminated peanut oil at temperatures of 10, 20, 30, 40 and 50 ℃ was collected, linear discriminant analysis (LDA) model was established for qualitative analysis, and partial least squares regression model was established for quantitative analysis. Results The accuracy of the single-temperature LDA detection model in predicting samples at this single temperature exceeded 84%. The global LDA model was lower prediction accuracy than the single-temperature LDA model. The partial least squares regression (PLSR) model could not achieve quantitative prediction at either single temperature or mixed temperature. The PLSR quantitative model developed for single-variety peanut oil demonstrated optimal stability at 20 °C, yielding the most accurate sample predictions. Conclusion This study proposes that a global model can be established during qualitative discriminant analysis to adapt to the impact of temperature on the detection process. In quantitative analysis, the single temperature model can achieve more accurate predictions than the global model.

In recent years, the impact of the food supply chain on carbon emissions has become a topic of great concern. Therefore, under the national “dual carbon” and “healthy China” strategies, the emergence of plant-based foods, represented by plant-based meat products, can simultaneously meet the national demand for low-carbon transformation and the increasing consumer demand for high-protein food intake, while optimizing the dietary structure of residents and improving their nutritional and health levels. This article elaborated on the main processing technologies of plant-based meat products, introduced the research progress of 3 main nutritional components of protein, dietary fiber, and lipids in plant-based meat products, and provided a systematic review of the health functions of consuming plant-based meat products, such as improving cardiovascular diseases, preventing obesity, maintaining intestinal health, and enhancing physical exercise functions. The aim is to promote the green and sustainable development of the food industry through the production of low-carbon emission meat products, build a healthy dietary pattern, improve the health level of the people, and provide a certain theoretical basis for the further research and development of plant-based meat products.

Objective To establish a method for the determination of 8 kinds of fungal toxins in rice noodles with liquid-liquid dispersion extraction and multifunctional purification by high performance liquid chromatography-tandem mass spectrometry. Methods Rice noodle samples were added with isotopic internal standards, and extracted by shaking with acetonitrile water (80:20, V:V) for 25 min. After liquid-liquid dispersion extraction, a multifunctional purification column was used for purification. The 8 kinds of target compounds were separated on HSS T3 column, with acetonitrile-water (0.1% formic acid) used as the mobile phase for gradient elution, and detected under positive and negative ionization and multiple reaction monitoring mode, determined with retention time and characteristic ion pairs, quantified with internal standard method. Results This method had a good linear relationship in detecting 8 kinds of fungal toxins within the corresponding range. The correlation coefficients (r) of the target compounds were 0.9954-0.9998. The limits of detection were 0.10-10.00 μg/kg, and the limits of quantification were 0.30-30.00 μg/kg. The average recoveries of rice noodle samples at low, middle and high standard additions were 75.8%-112.0%, and the relative standard deviations were 2.9%-5.9%. The detection and analysis of 8 kinds of fungal toxins in 21 kinds of rice noodle samples in the market showed that all the toxins were detected except HT-2. Conclusion The pretreatment of sample is simple, the method is accurate and sensitive, which can be used to determine the content of 8 kinds of fungal toxins in rice noodles.

Objective To establish a method for the determination of advanced glycation end products (AGEs) and 5-hydroxymethylfurfural (5-HMF) in loquat fruit paste by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Methods AGEs solution was obtained by extracting loquat fruit paste with pure water and treating with ultrasonic, centrifugation, solid-phase extraction and ammonia methanol solution elution, then separated by using gradient elution with 0.1% formic acid in water and methanol as the mobile phase. The detection method employed multi-reaction monitoring with positive ion. The 5-HMF solution was obtained by extracting the fruit paste in pure water, followed a liquid-liquid extraction with ethyl acetate, solid-phase extraction and 10% methanol elution. The extracts were analyzed at 30 ℃ with 10% methanol in water as mobile phase. Results It was found that the linearity of all the targets was good in the concentration range. The limits of detection and limits of quantification of each target substance were lower than 1 [AGEs/(ng/mL); 5-HMF/(µg/mL)], which could fulfill the requirements of detecting trace substances. The relative standard deviations (RSDs) of all the substances were less than 10%, and lower than 0.6% in the range of 16 hours of sample waiting time. The recoveries of all the substances were higher than 85%. Conclusion Results indicate that the method meet the basic requirement for quantitative analysis and has good accuracy and stability, which offers a detection means of studying on quality and safety of heat-processed fruit and vegetables.

Objective To detect mercury content in grain by direct injection method for mercury measurement.. Methods Direct injection method for mercury measurement was used to detect grain samples such as wheat, corn, and rice, and the limit of detection, accuracy, stability, and spiked recovery rate of the method were analyzed. Results When the sample size was 0.1 g, the limits of detection mercury in wheat, corn, and rice were 0.070, 0.075, 0.085 μg/kg, all of which were less than 0.2 μg/kg. The detection results of the quality control sample was 39.42 μg/kg, which was within the specified value range. The repeatability of mercury detection, with a relative standard deviation within 5%, met the stability requirements for mercury detection. The recovery rate of mercury spiked samples were 92.2%~101.4%. Conclusion Compared with traditional mercury analysis methods, direct injection method for mercury measurement has the advantages of simple operation steps, good repeatability, fast and accurate results, and is a recommended method for rapid detection of mercury content in grain.