Objective To compare the detection results of aflatoxin B₁ (AFB₁) content in various matrices such as rice, wheat products, and peanut products using 2 kinds of different pretreatment methods: Fully automated immunomagentic bead purification and immunoaffinity column pretreatment method. Methods After extraction with methanol:water (70:30, V:V), a portion of the extract was purified using the immunoaffinity column method with an AFB₁-specific immunoaffinity column, while another portion of the extract was processed by a fully automated immunomagnetic bead purification system paired with an immunomagnetic bead kit. Finally, both purified extracts were analyzed using high performance liquid chromatography coupled with post-column derivatization for detection. Results The efficacy of the immunomagetic bead purification kit and the column efficiency of the immunoaffinity column were both greater than 95%, which could meet the experimental requirements. Within mass concentration range of 1.00-50.00 ng/mL, the linear correlation coefficient (r) was 0.99993, indicating a good linear relationship. The 3 level spiked recovery experiments were conducted in rice matrix (n=6), and the recovery rates of the 2 kinds of pretreatment methods ranged from 98.2%-106.0%, with a relative standard deviation range of 1.0%-5.0%; single level spiked recovery experiments were conducted in wheat products (n=6), with a recovery rate exceeding 80% and a relative standard deviation of 3.7%-7.2%. Meanwhile, the 2 kinds of methods were used to detected AFB₁ positive peanut products and the quality control sample of corn flour matrix, their results were subjected to t-test, which showed no significant difference. Further, Bland-Altman statistical analysis was carried out on the results obtained from the quality control samples of corn flour matrix after 2 kinds of pretreatment methods were used. The results showed that the 2 kinds of methods could replace each other in the detection of AFB₁ in this matrix. The purification step of the immunoaffinity column method was time-consuming, 20 batches of samples take about 3-4 hours. And could only be manually operated, which generated about 1000 mL waste liquid; while the immunomagetic bead method used a fully automatic magnetic bead purifier, which automatically completed 20 batches of samples in 40 minutes at one time, with almost no waste liquid generated. Conclusion The fully automated immunomagnetic bead purification method and the immunoaffinity column method both can achieve good results in detecting AFB₁ in various matrices. Also, the immunomagnetic bead purification method is more efficient, easy to handle, generates less waste liquid, and the cost can be reduced by about 50%.

Objective To investigate the effects of low-temperature plasma-activated water (PAW) with varying treatment durations (5, 10, 15 minutes) on the quality of cold fresh Siniperca chuatsi slices. Methods This article used 0.15% lactic acid solution as the sterilization medium to soak cold fresh Siniperca chuatsi slices in PAW for 5, 10 and 15 minutes. The untreated samples served as the control group, refrigerated at 4 ℃. The pH, total bacterial count, total volatile base nitrogen (TVB-N), cooking loss, texture and sensory quality of the sample were measured every 2 days to evaluate the preservation effect of PAW. Results The results showed that after PAW treatment, the total bacterial count and TVB-N value of the sample were significantly inhibited, the pH decreased, the texture characteristics were maintained well, and the sensory quality of the sample were improved. PAW treatment could lead to an increase in cooking loss rate, and increase chewing ability of cold fresh Siniperca chuatsi slices. Conclusion The 15 minutes treatment group has the best preservation effect on cold fresh Siniperca chuatsi slices, maintaining good storage quality and prolonging the shelf life of cold fresh Siniperca chuatsi slices by 4 days.

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 optimize two kinds of detection methods in GB/T 37514—2019 Animal and vegetable fats and oils-Determination of mineral oils. Methods The saponification time was extended from 5 min to 10 min; a turbidimeter was introduced to measure the turbidity value of the saponified sample solution; a commercially available aluminum foil plate was used instead of the homemade alumina thin-layer plate; and 3 kinds of mineral oils were added to compare with the liquid paraffin in the standard. Results The turbidity values of some edible oils decreased to different degrees after prolonging the saponification time; the lowest limits of detection of diesel and liquid paraffin could reach 0.2% after replacing the aluminum foil plate; the limits of detection of different mineral oils by different methods were all different. Although the sensitivity of the optimized method was improved, it still did not fully meet the ideal standard for the detection of very small amounts of mineral oil residues in food safety regulation. Conclusion We call on the relevant departments to accelerate the improvement of the standardization system for the detection of mineral oil in food, and to promote the establishment of a more sensitive and scientific standard for the detection of mineral oil, so as to ensure the safety and quality of the edible oil market and to safeguard public health.

Objective To establish a method based on ultra performance liquid chromatography-quadrupole time of flight high resolution-mass spectrometry (UPLC-Q-TOF-MS) use as a rapid screening method for the illegal addition of 302 kinds of drugs in Chinese veterinary medicine. Methods A high-resolution mass spectrometry database containing information such as the names, molecular formulas, and exact mass numbers of 302 kinds of drugs was established. Samples were extracted with methanol and then analyzed by UPLC-Q-TOF-MS. A sample was considered as a suspected positive if the retention time deviation was less than 0.2 min, the mass error was less than 5 ppm, the isotopic ratio deviation was less than 5%, and the library matching score of the main characteristic fragment ions was greater than 80. Results The method exhibited good selectivity, with a minimum detection concentration as low as 50 ng/mL for the target substances (100 ng/mL for tetracyclines, penicillins, estrogens, and nonsteroidal anti-inflammatory drugs; 200 ng/mL for aminoglycosides). This enabled the efficient screening of 302 kinds of illegally added drugs. In the screening of actual samples, 7 batches of suspected positive samples were detected. Conclusion This approach is applicable for the screening of illegal additives in various veterinary Chinese medicines, providing effective technical support for the quality control of veterinary Chinese medicines.

Objective To explore the quality characteristics and differences among the fruits of 6 kinds of different Prunus salicina L. varieties: Fengtang plum, Candy red plum, Red plum, Jiangan plum, Green red crisp plum and Crisp plum, Qinghong Cuili, and Suli. Methods The nutritional components of Prunus salicina L. fruits were analyzed using liquid chromatography, amino acid analyzer, spectrophotometry, and titration methods, and a quality analysis of different Prunus salicina L. varieties was conducted. Results The study found that the soluble sugar content in Prunus salicina L. fruits was primarily composed of fructose, glucose, and sucrose, with glucose being the highest, followed by fructose or sucrose. The total soluble sugar content, total sugar content, soluble solids, sweetness value, and sugar-acid ratio of Fengtang plum were significantly higher than those of other varieties, which might be the main reason for its sweeter taste. In terms of organic acids, malic acid was the predominant organic acid, accounting for more than 88% of the total, with Candy red plum having the highest malic acid content and Green red crisp plum having the highest total acid content. Amino acid analysis revealed that aspartic acid and proline levels were relatively high, and Candy red plum had the highest total free amino acid content. Green red crisp plum had the highest levels of total flavonoids and vitamin C, while Red plum had the highest vitamin E content. Conclusion The fruit qualities of the 6 plum varieties showes significant differences. This study provides a theoretical foundation and practical guidance for the utilization of quality resources of different plum varieties and the premium strategy for Prunus salicina L. fruits.

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 screen lactic acid bacteria strains with strong ethanol stress resistance and investigate the effects of their biofilms under different ethanol concentrations and environmental disturbances. Methods The growth, biofilm formation, morphological changes and hydrophobicity of various lactic acid bacteria under ethanol stress were examined. The effects of different metal ions and D-galactose on the growth and biofilm formation of lactic acid bacteria were also explored. Results After 48 h of fermentation under 10% ethanol stress, the biomass and biofilm amount of Lacticaseibacillus paracasei were 1.16 and 0.12, respectively. After 24 h of fermentation, its hydrophobicity reached 42.80%, significantly higher than that of Lactiplantibacillus plantarum, Lacticaseibacillus casei, and Limosilactobacillus fermentum, indicating better ethanol stress resistance. Scanning electron microscopy showed that the thickness of the biofilm decreased significantly with increasing ethanol concentration. The addition of D-galactose and metal ions (Ca²⁺, Na⁺) significantly inhibited biofilm formation. Conclusion Lactic acid bacteria resist ethanol stress through biofilm formation, with ethanol stress resistance correlating closely to biofilm production. D-galactose and metal ions affect the growth and biofilm formation of lactic acid bacteria. This study reveals the relationship between ethanol stress resistance and biofilm formation in lactic acid bacteria, provides a theoretical basis and data support for developing lactic acid bacteria biopreparations suitable for high-ethanol food fermentation environments.

Objective To evaluate the quality differences among the main Vitis vinifera L. varieties in Shanghai, identify key quality indicators. Methods A total of 34 batches of Vitis vinifera L. samples were collected from 10 major cultivars cultivated by 7 enterprises in Shanghai. Twelve quality parameters, including cluster weight, berry weight, fructose, glucose, total acid, vitamin C, amino acids, and anthocyanins, were analyzed to assess Vitis vinifera L. quality from 3 perspectives: Physical appearance, intrinsic nutritional quality and overall quality. Results There were significant differences (P<0.05) in the physical appearance, intrinsic nutritional quality and overall quality of Vitis vinifera L. varieties. Shine Muscat performed exceptionally well in sugar-acid balance, Zuijinxiang showed high levels of vitamin C and overall nutritional quality, Jumeigui had a notable advantage in fructose and glucose content, and Shenyuan exhibited the highest total amino acids, though the amino acid composition needs optimization. Principal component analysis revealed that the main factors contributing to quality differences were the sugar-acid ratio, amino acid composition and fruit weight. Conclusion The major Vitis vinifera L. cultivars in Shanghai exhibit distinct quality advantages. Shine Muscat, Zuijinxiang and Jumeigui are particularly suitable for promotion as premium table Vitis vinifera L. varieties. These findings provide a scientific basis for Vitis vinifera L. varieties breeding, cultivation management, and market positioning, while also serving as a reference for consumer health and the development of functional foods.