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.

Objective To explore the mixing ratio of different oil seeds in microwave-assisted blended cold pressing process, and develop polyunsaturated fatty acid balanced oil that meets the recommended dietary intake ratio. Methods The safflower seed and flaxseed were used as raw materials. The process parameters were optimized by single factor experiment (microwave treatment time, pressing temperature and moisture content of oil seed) and Box-Behnken response surface experiment. The oxidation characteristics of blended cold pressed oil were compared and analyzed. Results The mass ratio method determined that the blended mass ratio range was 1.8-2.4 (safflower seed:flaxseed, W_s:W_f). This method was simple and the results did not need to be verified, but it had the disadvantages of large demand for raw materials and low accuracy of boundary value. The mixing ratio range determined and verified by the fatty acid ratio method was 1.66-2.59 (W_s:W_f). This method had less raw material demand and high accuracy near the boundary value. However, due to the interaction of oil seeds, verification experiments needed to be carried out. Response surface methodology was used to optimize the process parameters of microwave-assisted blended cold pressing. The optimal extraction conditions were as follows: Microwave (800 W) treatment time 1.5 min, cold pressing temperature 64 °C, oil seed moisture content 6.7%, oil extraction rate 19.83%±0.21 %, which was 17.2% higher than that before optimization. The basic physical and chemical indexes of blended cold-pressed oil and traditional cold-pressed blend oil were compared and analyzed. The oil oxidation degree was lower under the condition of microwave-assisted blended cold-pressed process. Conclusion Microwave-assisted blended cold pressing oil has lower primary and secondary oxidation product indexes than traditional cold-pressed blended oil. The results can provide a theoretical basis for the preparation of polyunsaturated fatty acid equilibrium oil and the application of microwave-assisted blended cold pressing process in the field of grain and oil processing.

Objective To construct a quality evaluation system for the main-sold pork in Shanghai and analyze the appearance, texture, nutrition, and flavor indicators of different pig breeds. Methods A total of 95 samples of the longissimus dorsi muscles were collected from 7 boar breeds, including Pudong White pigs. Fifty-five parameters were detected. Correlation analysis and radar charts were used to determine the core indicators for quality evaluation. Results In terms of appearance quality, different pig breeds showed differences in indicators such as pH and moisture content. Shawutou pigs, Pudong White pigs and Shanghai White pigs had slightly lower water content, while Shawutou pigs had a high drip loss rate. Topigs had slightly higher intramuscular fat content. Correlation analysis showed that the water content was negatively correlated with 24-hour drip loss. Regarding texture, Fengjing pigs had high shear force, Topigs had high hardness. Correlation analysis showed that the shear force was negatively correlated with hardness and positively correlated with elasticity. In terms of nutritional quality, it showed that the protein content in Shanghai local pig breeds was higher than that in common Duroc-Landrace-Yorkshire pigs. Three-way crossbred pigs and Shanghai White pigs had slightly lower fat content. The proportion of essential amino acids was the lowest in three-way crossbred pigs. In terms of flavor quality, the total amount of umami amino acids in each pig breed was similar. Shanghai White pigs had a high content of cytidine monophosphate, three-way crossbred pigs and Fengjing pigs had a high content of uridine monophosphate, Topigs had a low content of multiple flavor-related nucleotides, and Shawutou pigs had a high content of adenosine monophosphate. Correlation analysis showed that aspartic acid was positively correlated with the total amount of umami amino acids. Conclusion A quality evaluation system for Shanghai pork can be constructed around 13 core indicators, including water content, conductivity, shear force, hardness, resilience, protein, fat, magnesium, potassium, selenium content, adenosine monophosphate, inosine monophosphate, and aspartic acid. In the future, relevant factors need to be comprehensively considered to construct a comprehensive evaluation model.

Objective To evaluate the food safety and quality of prepared dishes sold in Guangdong Province from 2021 to 2023. Methods According to the national definition and scope of prepared dishes, and considering their 5 main characteristics, relevant data were selected from the food supervision and sampling inspection database of Guangdong Province from 2021 to 2023. Additionally, 20 batches of frozen meat products were randomly purchased from supermarkets and stores within the province for animal-derived component testing. The results were evaluated based on food safety national standards and statistically analyzed using WPS Office 2024. Results The supervision sampling inspection data of prepared dishes sold in Guangdong Province from 2021 to 2023 covered 8910 batches and 20019 items, with 18 testing items including physicochemical indicators, contaminants, microorganisms, and animal-derived components. The compliance rate for all items except the microorganism indicator in meat products exceeded 99%. Among the 20 randomly purchased frozen meat products, 15 batches were detected to contain other animal-derived components. By analyzing the above data, several issues were identified in prepared dishes: Food classification could be easily confused; some products lack evaluation criteria for contaminants; microbial contamination was of concern; and the detection rate of other animal-derived components in beef products was high. Conclusion Overall, the food safety of prepared dishes in Guangdong Province is satisfactory. To address the identified issues, effective control measures should be implemented. This study proposes standardizing the classification criteria for supervision and sampling inspection of prepared dishes, expediting the release of national food safety standards, enhancing the prevention and control of microbial contamination, and strengthening the management of raw material authenticity to promote the healthy development of the prepared dishes industry.

Objective To explore the effects of curcumin and vitamin C supplementation on harmful substances heterocyclic amines (HAAs) and advanced glycation end products advanced glycation end products (AGEs) in Salmon salar roasting process inhibition and the effect of exogenous additives on the flavor of grilled Salmon salar. Methods The concentrations of HAAs and AGEs were determined by high performance liquid chromatography-tandem mass spectrometry, and the inhibitory mechanism of reducing sugar, creatine, creatinine, glyoxal and other precursors and lipid oxidation levels were further determined. The changes of volatile flavor of Salmon salar during baking were analyzed by gas chromatography and ion migration spectrometry. Results Compared with the control group, curcumin and vitamin C showed significant inhibitory effects on HAAs and AGEs (P˂0.05), and the total HAAs inhibition rates were 75.21% and 59.52%, respectively. The inhibition rates of N^ε-carboxymethyl-lysine in AGEs were 90.56% and 90.87%, respectively. The inhibition rates of N^ε-carboxymethl-lysine were 94.57% and 94.80%. The concentrations of precursors such as reducing sugar, creatine, creatinine and glyoxal were highly correlated with the content of HAAs and AGEs. In addition, volatile flavor analysis showed that the addition of curcumin and vitamin C had a certain effect on the flavor of grilled Salmon salar, and increased the concentration of aroma compounds such as 3-hydroxy-2-butanone, 2,6-dimethyl- 7-octene-2-ol and menthol, which contributed to the overall smell of Salmon salar. Conclusion Curcumin and vitamin C affect the key precursors and intermediates in the formation of HAAs and AGEs, and have a significant inhibitory effect. The development of this study provides theoretical guidance for the control of harmful substances in hot processing of fish products, and provides reference for optimizing the processing technology of fish products.

To address the current situation where a large number of imported prepackaged foods are denied entry due to non-compliant labels, and to promote the production and review of labels for imported prepackaged foods, this study provided countermeasures and suggestions for mitigating risks associated with label marking of imported prepackaged foods. This review based on current national food safety standards, the Chinese labeling content of imported prepackaged foods is summarized as “8+1+X”, which included 8 mandatory pieces of information: Food name, ingredient information, production date, shelf life, storage conditions, domestic distribution information (including the name, address, and phone number of the distributor/importer), country or region of origin, net content, plus the registration number in China and other special labeling requirements. By comparing the “8+1+X” labeling requirements, the study analyzed non-compliant labeling cases of imported prepackaged foods over the past 3 years and identified risks associated with label marking. By analyzing the root causes, this study proposes 5 countermeasures: Enhancing the awareness and risk perception of foreign trade practitioners, improving their professional competence, leveraging modern software technologies for technical support, promoting the establishment of related industries and technological advancements in relevant fields, and refining regulations and standards. These strategies aimed to effectively reduce the risks associated with the labeling of imported prepackaged foods. Therefore, improving technical capabilities, introducing new label review models, and standardizing the labeling of imported prepackaged foods are essential measures to maintain market order, protect consumers’ right to know and choose, and ensure national dietary nutrition and safety. These efforts must be given due attention.

Objective To establish a detection method for rapid determination of chlorate and perchlorate in Capsicum annuum L. powder by automatic QuEChERS-ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods After the sample was centrally weighed, the sample was extracted with a mix-ture of 1% avetic acid-acetonitrile-water (1:1, V:V), and automatic pre-treatment with automatic QuEChERS instrument, the gradient elution was performed by 0.5% formic acid methanol-0.5% formic acid solution, Thermo HYPERCARB as a separation column, gradient elution, series mass spectra electrospray ionization negative mode ionization, multiresponse monitoring pattern detection, qualitative research by the ratio of retention time and ion, the internal standard method was used to qualitative experiment. Results Automatic QuEChERS instrument was used to determine the chlorate and perchlorate of Capsicum annuum L. powder and the pretreatment efficiency was 6 times that of manual. The limits of quantification (S/N=10) were 10 μg/kg, when the spiked level was 10-50 μg/kg (n=6), the sample recoveries for chlorate and perchlorate were 94.0%-96.4%, the relative standard deviations were less than 5%. The calibration curves were linear in the range of 1-100 μg/L with the correlation coefficients above 0.999. Conclusion The method has high automation degree, good accuracy and stability, and the limit of quantitation also meets the requirements of European Union export, can be applied for the determination of chlorate and perchlorate in Capsicum annuum L. powder.

Objective To establish a method for the simultaneous determination of 10 kinds of phytotoxins, including tripterygium wilfordii and aconite in honey by ultra performance liquid chromatography-tandem mass spectrometry. Methods The samples were extracted by vortexing with 1% formic acid water-70% acetonitrile water solution. After high-speed centrifuged, added appropriate amount of primary secondary amine (PSA) to the supernatant, and shaked and mixed evenly, passed through 0.22 μm filter membrane, then determined and analyzed by the instrument. The matrix working curve was used for quantification by the external standard method. Results The limits of detection of 10 kinds of phytotoxins were 0.03-1.90 μg/kg. The 10 kinds of phytotoxins showed good linearity in a certain range of mass concentration with the correlation coefficients were all greater than 0.999. The average recovery rates of toxins ranged from 89.5% to 113.8% at 3 kinds of different concentration spiked levels, and the relative standard deviations of 0.5%-8.7%. Conclusion The method is convenient, sensitive and accurate, and provides technical support for rapid screening of phytotoxins in emergencies. It is suitable for simultaneous determination of various phytotoxins in honey samples, especially in batch samples.

Objective To study the accuracy and feasibility of colloidal gold immunochromatography for the detection of animal-derived components in meat products. Methods The rapid detection kit was used to detect the animal-derived components in meat products. The sensitivity, specificity, adulteration simulation, false positive rate and false negative rate of 8 kinds of animal-derived components were tested, and quantitative real-time polymerase chain reaction (QPCR) was used as a reference. Results The limits of detection of the rapid detection kit could reach 0.1% for cattle, chicken, duck and goose, and 0.01% for pig, sheep, horse and donkey. The limits of detection of pig, cattle, sheep, chicken, duck, goose, horse and donkey in the adulterated simulation could reach 0.5%, and there was no cross-reaction with other non-species channel detection, and the specificity was good. Conclusion The colloidal gold immunochromatography method established in this study is suitable for the rapid screening and detection of animal origin in meat products.

Objective To systematically analyze the nutrition, taste and texture characteristics of salt field shrimp, an ecological shrimp (Penaeus vannamei) that grows in salt field evaporation ponds or muddy and sandy water surfaces with a salinity of over 30‰. Methods Taking freshwater cultured Penaeus vannamei (D0) as control, the conventional nutritional components, amino acids, fatty acids, major mineral elements, active substances, free amino acids, nucleotides, quaternary ammonium compounds, organic acids, texture, and color after cooking of two kinds of salt field shrimps cultured in different salinity fields (Penaeus vannamei, recorded as Y45 and Y30 separately) in Binzhou City were analyzed, and their nutritional quality was evaluated. Results Compared with freshwater shrimp, salt field shrimp had higher protein and ash content, and lower fat content. The 18 kinds of amino acids were detected in both salt field shrimp and freshwater shrimp, with glutamic acid being found the highest level, followed by aspartic acid, and tryptophan the lowest content. The proportion of essential amino acids to the total amino acid content in shrimp of all 3 groups were higher than 35.38%, and the essential amino acid index was much higher than 100, indicating balanced amino acids and high nutritional value. The unsaturation degree of fatty acids in all three groups of shrimp was high and the mineral elements such as calcium, sodium, chlorine, and magnesium in salt field shrimp were significantly higher than those in freshwater shrimp. The content of active substances such as taurine and astaxanthin was much higher than that in freshwater shrimp, but their body color tended to be lighter after cooking. The nutritional quality index of protein, phosphorus, sodium, chlorine, and magnesium in salt field shrimp was much higher than 1, indicating that salt field shrimp had greater ability to provide these nutrients than to provide thermal energy. In terms of flavor substances, the content of free amino acids in salt field shrimp was as high as 3119.88 mg/100 g (Y45), and the content of Na⁺, Cl^-, betaine, and tartaric acid was significantly higher than that in freshwater shrimp. Free amino acids Arg, Gly, Ala, Glu, inorganic ions, betaine, tartaric acid, lactic acid, and succinic acid were the main contributors to its taste, while other organic acids, flavor nucleotides, reducing sugars, etc. also provided it with richer taste. From the texture results, it could be seen that the muscle hardness and shear force of salt field shrimp were low and the elasticity was high, which means the meat of salt field shrimp was more tender than that of freshwater shrimp. Conclusion In summary, salt field shrimp (Penaeus vannameii) is a food with high protein, low fat, balanced amino acid composition, fresh and sweet taste, and high dietary nutritional value.