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.

With the continuous improvement of people's consumption capacity and consumption level, baking foods are deeply loved by consumers for their rich nutrition, great taste, fashion, easy to carry and other characteristics. Baking foods often need to dehydrate the dough through high temperature and dry hot baking to dry and harden, and then chemical changes such as starch gelatinization and protein denaturation occur, and the result is delicious bread, cakes, etc. However, this kind of food would form large amounts of 5-hydroxymethylfurfural (HMF) and other pollutants during the baking process. When the content of HMF exceeded a certain limit, it would cause harm to the human body. High concentration of HMF is cytotoxic, mutagenic, genotoxic, etc., and has potential health risk to humans. How to control the formation of contaminants such as HMF in baking foods has become the focus of the food industry. This article reviewed the sources of HMF in baking foods and the toxicity of HMF, summarized the inhibition measures of HMF in baking foods in recent years from 3 aspects of improving the types of precursors in raw materials, optimizing the baking process, and adding inhibitors, to provide theoretical reference for the control of HMF in the industrial production of baking foods.

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.

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.

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 explore the effects of the addition of low glycemic index (GI) corns tarch on the quality of biscuits and the in vitro starch digestibility. Methods Biscuits were prepared using wheat flour as the main ingredient and replacing wheat flour with low GI corn starch at 5 kinds of ratios of 0%, 10%, 20%, 30%, and 40%, and the quality characteristics and sensory characteristics of the biscuits was measured and analyzed. Their in vitro starch digestibility and the rheological properties of the digesta were investigated. Results Crude protein content was highest in the low GI corn starch biscuits with an addition level of 10%, at (7.65±0.10)%. Meanwhile, the carbohydrate content was lowest in the low GI corn starch biscuits with an addition level of 20%, at (66.14±1.50)%. The addition of low GI corns tarch increased the hardness and crispness of the biscuits, while improving their chewiness; when the addition was 10%, the biscuits received the highest scores for color, scents, texture, and organizational structure. As the amount of low GI corns tarch added increased, the estimated glycemic index (eGI) of the biscuits decreased, and the viscosity of the digesta increased. Conclusion Adding an appropriate amount of corns tarch can effectively improve the GI value of biscuits, providing a fundamental experimental basis for the development of low GI foods, and offering new insights into the application of corns tarch in the food industry.

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 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.

Tannins, a diverse group of polyphenolic compounds found within botanical realm, are extensively utilized across the food processing industry, medicinal applications, and cosmetics production. Considering the inherent bitter or sour characteristics of tannins, the regulation of their concentration is crucial for enhancing the quality of food products. In the context of tannin degradation processes, microorganisms harness the catalytic prowess of tannase to effectuate the degradation of tannins. Tannase is mainly produced by bacteria and fungi derived from microorganisms during metabolic processes. Its role in tannin degradation is not only to ameliorate the inhibitory effects of tannins on microbial populations but also to enhance the metabolic recycling of the byproducts derived from tannin degradation. Considering the biochemical diversity and enzymatic stability inherent to tannases, these enzymes have garnered extensive application within a multitude of industrial sectors, including but not limited to food processing, animal feed production, pharmaceutical development, and chemical manufacturing. The article provided a concise overview, elucidating the structural classification and degradation pathways of tannins while articulating the enzymatic mechanisms employed by microorganisms to metabolize them. It summarized the applications of tannase in food sectors such as nuts, tea, juice, and noodles, and explored the potential of current methods for screening high-yield, high activity, and high degradation rate tannase strains. These efforts aimed to provide references for the development of high-quality microbial resources and the expansion of enzymatic catalytic functional characteristics.