Objective To develope a method based on organic solvent extraction and solid phase extraction purification combined with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for the simultaneous determination of 23 kinds of perfluorinated and polyfluoroalkyl substances (PFASs), including perfuluorocarboxylic acids, perfluoroalkyl sulfonic acids, and fluorotelomer sulfonic acids, in freshwater fishes. Methods The chromatographic conditions and mass spectrometry parameters were optimized, and the effects of extraction solvent and solid phase extraction column fillers on sample recovery and purification were investigated. The optimal sample pretreatment and instrument conditions were determined. Freshwater fish samples were directly extracted with 2% formic acid and purified using a lipid removal PPR Pro column. With 5 mmol/L ammonium formate aqueous solution and methanol as mobile phase, the target substances were separated by C₁₈ chromatographic column. The mass spectrum was detected by electrospray ion source (ESI^-), multi reaction monitoring (MRM) and stable isotope internal standard method. Results The 23 kinds of target PFASs had a good linear relationship within 0.5-100.0 ng/mL mass concentration range (r²>0.980), with the limits of detection was 0.030-0.146 μg/kg and the limits of quantification were 0.100-0.567 μg/kg. The spiked recoveries of serum sample were 72.9%-111.0%, with relative standard deviations of 3.0%-17.5% (n=9). Conclusion The method has the advantages of simple operation, high sensitivity, strong anti-interference and good precision, and is suitable for the rapid detection and analysis of 23 kinds of perfluoroalkyl carboxylic acids, perfluoroalkyl sulfonic acid and polyfluorotelomeric sulfonic acid in freshwater fish.

Chinese sour bamboo shoot, as a traditional fermented food, is mainly made from fresh bamboo shoots through natural fermentation or inoculated fermentation. It is widely popular in Southern China due to its unique flavor and rich nutritional content. Sour bamboo shoots are rich in cellulose, vitamins, minerals, and various beneficial microorganisms, offering significant nutritional value. Their distinctive sour taste and aroma primarily originate from volatile and non-volatile compounds produced during the fermentation process, including lactic acid, acetic acid, esters, and alcohols. In recent years, with the development of modern fermentation technology, researchers have made significant progress in the selection of fermentation strains, optimization of fermentation conditions, and product quality control of sour bamboo shoots. This article reviewed the main nutritional components, flavor compounds, and the research progress of its fermentation technology, providing a theoretical basis for improving the production process of pickled bamboo shoots, enhancing product flavor quality, and achieving standardized production.

Objective To clarify the impact of gastrointestinal fluid digestion on the biological activity of Flammulina velutipes, to investigate the effect of in vitro digestion on the antioxidant activity and α-glucosidase and α-amylase inhibitory activity of Flammulina velutifolia powder. Methods In this study, Flammulina velutipes powder was simulated in vitro digestion of intestine and stomach and analyzed. With 1,1-diphenyl-2-picylhydrazyl (DPPH) free radical, OH free radical, O₂^- free radical and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺) free radical, α-glucosidase and α-amylase inhibition were used as indexes to study the antioxidant activity of Flammulina velutipes powder at different digestion stages. Results After in vitro digestion, the antioxidant activity of Flammulina velutipes powder was enhanced and the free radical scavenging ability of DPPH, OH, O₂⁻ and ABTS⁺ free radical increased. The antioxidant capacity of the digested group was higher than that of the non-digested group. Its inhibitory activity against α-glucosidase and α-amylase was also enhanced and positively correlated with the concentration, and the strongest inhibitory effect on 2 kinds of enzymes was observed after intestinal digestion. Conclusion The antioxidant activity and enzyme inhibitory activity of Flammulina velutipes powder are enhanced after in vitro digestion, which indicate that the digestion process can release and enhance the bioactivity of Flammulina velutipes. However, in vitro antioxidant activity is not directly related to the actual antioxidant activity of the material. This study provides a basis for the processing and utilization of Flammulina velutipes and its activity research.

Objective To prepare of Lycium barbarum and Hordeum vulgare lozenges and study of its safety quality. Methods The wolfberry and barley were ground into powder and sifted, mixed 1:1 into Lycium barbarum and Hordeum vulgare powder, kneaded into a dough with butter, and put into a grinding tool for tablet drying. The determination of toxic and harmful microorganisms and basic nutritional indexes including moisture, ash, protein, fat and starch was carried out on Lycium barbarum and Hordeum vulgare lozenges. The sensory evaluation team will score the product for sensory evaluation. Results No toxic and harmful components were detected in the lozenges of Lycium barbarum and Hordeum vulgare, and the moisture content was about 5.84%. The ash content was about 3.34%. The protein content was about 12.34%. The fat content was about 17.01%. The starch content was about 47.35%. The finished lozenge had uniform color and no special spots, complete shape without breakage, smooth taste with slight graininess, and moderate sweetness and sourness. Conclusion In this study, the utilization rate of wolfberry was improved by combining wolfberry and highland barley into lozenges, which promote the development of highland barley industry and provide a new way for wolfberry-related products.

Objective To investigate the effects of aging time on the volatile flavor components of soy sauce. Methods Differences in volatile aroma components between black bean soy sauce and soybean meal soy sauce aged at different times were analyzed using electronic nose combined with headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), and key aroma components were identified using odor activity value (OAV) method. Results A total of 1227 kinds of volatile substances were detected in 6 kinds of soy sauce samples with different aging times, mainly including 265 kinds of esters, 155 kinds of terpenes, 153 kinds of ketones, 137 kinds of heterocyclic compounds, 104 kinds of alcohols, 77 kinds of acids, 72 kinds of aldehydes, 59 kinds of phenols, 54 kinds of hydrocarbons, 50 kinds of amines, 30 kinds of aromatic hydrocarbons, 27 kinds of ethers, 26 kinds of nitrogen-containing compounds, 9 kinds of sulfur-containing compounds, and 9 kinds of halogenated hydrocarbons. With the increase of aging time, the types and relative content of volatile compounds in black bean soy sauce and soybean bean soy sauce showed significant differences (P<0.05), and the key aroma components contribute significantly to the overall flavor characteristics. Electronic nose technology could effectively distinguish the volatile aroma characteristics of soy sauce with different aging times, and was consistent with the trend of changes in volatile flavor compounds. A total of 132 kinds of key aroma components (OAV>1) were identified through OAV, among which aldehydes, phenols, and terpenes contributed the most to the overall aroma of soy sauce. Conclusion This study reveals the influence of different aging times on the volatile components and aroma quality of black bean soy sauce and soybean meal soy sauce, providing theoretical and experimental references for the improvement of soy sauce and flavor quality.

Caffeine is an important functional active substance in tea. The caffeine content in different types of tea varies, which is related to the tea raw materials and different processing techniques. Separating and extracting caffeine from tea leaves can not only obtain tea with low caffeine content, but also meet a wider range of tea drinking needs. On the other hand, it is to obtain high-purity caffeine for use in fields such as medicine and food. The extraction and separation of tea caffeine involves various new extraction methods, including chemical, physical, biological, and others. The key to efficient, high-purity separation and protection of other active substances in tea is the extraction and separation technology. Caffeine also plays an important role in the basic quality, flavor, sensory perception, and activity of tea. Different amounts of caffeine can have an impact on various systems in the human body, and moderate intake can bring beneficial effects. Its functions and applications in antibacterial, catalytic, plant biostimulant, and food packaging materials are also very extensive. This article summarized the synthesis, metabolism, content, and influencing factors of caffeine in tea, summarized the extraction and separation techniques of caffeine in recent years, and evaluated the efficiency and applicability of various methods. In addition, to explore the influence of caffeine on tea quality and its various functional activities and applications, in order to break through some drinking restrictions of tea and better develop and utilize caffeine in tea.

Objective To establish a method for the simultaneous determination of 70 kinds of pesticide residues in vegetable wastes by QuChERS (Quick Easy Cheap Effective Rugged and Safe) and ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods Vegetable wastes samples were extracted and purified by QuChERS method, then the samples were detected by UPLC-MS/MS, and the electrospray ionization source was used simultaneous scanning, detected under multiple reaction monitoring mode, matrix-matched calibration curve, and quantified by external standard method. Results The 70 kinds of target pesticides exhibited great linear relationships within the concentration range of 2.0-200.0 μg/L, with linear correlation coefficients were all greater than 0.99. The average recoveries ranged from 61.7% to 109.9%, the relative standard deviations were 0.4%-9.7%, with 3 addition levels at 0.002, 0.004 and 0.020 mg/kg. The limits of detection were in the range of 0.0001 to 0.0020 mg/kg, and the limits of quantification were in the range of 0.0003-0.0060 mg/kg. Conclusion This method is easy operation, fast, accurate, and good sensitivity, which is suitable for the simultaneous detection of pesticide residues in a large number of vegetable wastes samples.

Objective To evaluate the effects of sub-chronic doses of paralytic shellfish toxins (PSTs) on the livers of mice. Methods In the present study, the effects of different dose concentrations PSTs on hepatic lipid metabolomics were assessed by oral gavage using the lipidomics technique. Results Exposure to the high-and medium-dose group (greater than 100 µg STXeq/kg BW) resulted in abnormal lipid metabolism, with glycerophospholipids (GP) as the major differential lipid metabolites, phosphatidylethanolamine (18:3/22:6) [PE (18:3/22:6)], PE (16:0/18:0), and 16(17)-epoxydocosapentaenoic acid were lower, whereas the relative content of lysophosphatidylethanolamine (P-16:0/0:0) was elevated in relative levels of these lipids, which might serve as biomarkers of liver injury due to PSTs exposure. In contrast, the low dose group (45 µg STXeq/kg BW) did not significantly affect mouse liver lipids. Metabolic pathway enrichment analysis of differential lipids showed that α-linolenic acid metabolism, glyceride metabolism, arachidonic acid metabolism, and steroid hormone biosynthesis were collectively involved in lipid metabolism in the 3 kinds of PSTs experimental groups. Conclusion The effects of PSTs on hepatic lipid metabolism in mice are characterized by a dose-dependent pattern, and lipid dysfunction may affect the neurotoxic effects of PSTs. This study provides a theoretical reference for exploring the mechanism of hepatic injury by PSTs in mice.

Objective To study and analyze the content of aflatoxins in Hunan characteristic chili sauce and the main sources of aflatoxin contamination. Methods Content of aflatoxins in raw materials, wheat germ, semi-finished products, and finished products in Hunan characteristic chili sauce enterprises for 3 consecutive years was tracked and monitored. Traditional cultivation methods and gene sequencing technology was used to isolate and identify fungi in key production processes, and determine the main source links and strains of aflatoxins in Hunan characteristic chili sauce. Results Due to the influence of traditional techniques, the content of aflatoxin in spicy sauce products of various enterprises was unstable, with the highest aflatoxin content occurring in the wheat germ stage. Rhizopus and Aspergillus oryzae may be the main dominant microorganisms in the growth of spicy sauce. The 14 strains of fungi were isolated and screened from samples with high levels of aflatoxin, of which 6 strains were Aspergillus flavus. Through verification and traceability analysis, it was found that the main source of aflatoxin content in spicy sauce was Aspergillus flavus in raw materials or wheat germ. Conclusion Important step in the production of aflatoxin in Hunan characteristic chili sauce is the wheat germ making process, and the main source of aflatoxin is Aspergillus flavus. Therefore, the isolation, identification, and traceability research of Aspergillus flavus in Hunan characteristic chili sauce have important guiding significance for the quality and safety control of Hunan characteristic chili sauce.

Objective To optimize the formula and processing technology of braised pork. Methods The pork belly was cured by ultrasonic treatment for 30, 45 and 60 min and static curing as the control. The marinade uptake, production rate, drip loss rate and cooking loss rate were used as indicators to compare the effects of ultrasonic and static curing on curing efficiency and quality. The sensory characteristics of braised pork made by traditional and vacuum low-temperature slow cooking techniques were compared by measuring the moisture content, thermal processing loss and sensory scores. The formula of braised pork was optimized by using sensory scores as the index and conducting single factor and orthogonal experiments. Results Compared with static curing, different ultrasonic treatment times were beneficial to the improvement of the marinade uptake and production rate of the meat, and the cooking loss rate and drip loss rate were significantly lower than those of the static curing group. The marinade uptake was the highest after 60 min of ultrasonic treatment, and there was no significant difference in the production rate between 45 min and 60 min of ultrasonic treatment. With the extension of ultrasonic treatment time, the drip loss rate gradually increased, reaching a maximum of 6.20%, and the cooking loss rate was relatively low after 45 min and 60 min of ultrasonic treatment. Overall, ultrasonic curing for 45 min was the most effective. In terms of vacuum low-temperature slow cooking technology, the total sensory scores of 65 ℃ and 70 ℃ for 6 h and 70 ℃ for 8 h were relatively high. When the slow cooking temperature was set at 70 ℃ for 6 h, the color, aroma, taste and texture of braised pork were significantly improved. Compared with the traditional process, the cooking loss rate was significantly reduced and the moisture content was significantly increased. In terms of formula optimization, the sugar-oil-water mass ratio had the most significant effect on the sensory score, followed by spices and dark soy sauce. The optimal formula was determined as follows: 250 g of streaked pork, 30 g of sugar solution (including 15 g of white granulated sugar, 6 g of vegetable oil, and 9 g of water), 6 g of soy sauce, 5 g of Huadiao wine, 400 g of water, 2 g of anise, 0.2 g of fragrant leaves, and 1.2 g of cinnamon. Conclusion The ultrasonic assisted curing and sous-vide technology can effectively improve the quality of braised pork, and the improved formula technology makes the comprehensive sensory evaluation of braised pork the best.