Objective To establish a method for the simultaneous detection of multiple amino acids in each part of pork by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Methods The samples were extracted by acidizing high-temperature hydrolysis, acidizing microwave hydrolysis and alkalization high-temperature hydrolysis, determined by HPLC-MS/MS, electrospray ionization in positive ion mode, multiple reaction monitoring (MRM), used formic acid solution-methanol acetonitrile (1:4, V:V) solution of formic acid as mobile phase with gradient elution. Results It was extracted by acidizing microwave hydrolysis with short time and high efficiency. The detection method had a good relationship in the linear range, r² was between 0.9905 and 0.9956, the limits of detection were 0.012-0.133 ng/mL, the limits of quantitation were 0.038-0.444 ng/mL, the average recoveries were in the range 85.58% and 98.84%, the relative standard deviations (RSDs) were 0.68%-6.71%. Conclusion The method has simple process, good repeatability and stability, and can not only be used for simultaneous detection of multiple amino acids in each part of pork to achieve the purpose of high-throughput and rapid detection, but also can effectively monitor the adulteration behavior of pork products.

Objective To investigate the effects of varying heat treatment conditions on the texture profile and volatile/non-volatile flavor compound dynamics in fermented milk produced by Lacticaseibacillus paracasei K56. Methods Fermented milk produced by Lacticaseibacillus paracasei K56 was subjected to heat treatment at temperatures ranging from 80 to 121 ℃. The texture, volatile flavor compounds and non-volatile flavor compounds were analyzed using a texture analyzer, headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS), and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results Under heat treatment conditions ranging from 80 to 110 ℃, the hardness of fermented milk produced by Lacticaseibacillus paracasei K56 decreased, while cohesiveness, and springiness increased. The optimal textural properties, particularly in terms of cohesiveness and gumminess, were achieved at 110 ℃ for 4 s, exhibiting a hardness of 6.2 g, cohesiveness of 0.18, springiness of 0.708 mm, and gumminess of 4.8 g. The 59 kinds of volatile flavor compounds were detected following heat treatment, with the 90-121 ℃ range significantly enhancing the levels of ketones and alcohols. Odor activity value (OAV) analysis identified esters, ketones and organic acids as the dominant flavor contributors in the fermented milk, with δ-decalactone and isoamyl acetate serving as the key odorants. Among the 652 kinds of non-volatile metabolites analyzed, the heat treatment groups 90 ℃, 15 min and 110 ℃, 4 s, 100 ℃, 15 min and 115 ℃, 4 s exhibited overlapping metabolites. Comparative analysis revealed 12 significantly differentiated indole compounds among the control group and 6 heat-treated samples. Conclusion The textural properties and flavor compounds of fermented milk produced by Lacticaseibacillus paracasei K56 vary significantly under different heat treatments. The treatment at 110 ℃ for 4 s achieves optimal results, enhancing texture and increasing flavor diversity. These findings provide a critical scientific basis for quality enhancement in fermented dairy products.

Objective To optimize the new product formulations of zero-fat oil vinegar liquid seasoning based on the quantitative descriptive analysis and consumer preference testing. Methods Quantitative descriptive analysis was used to confirm the main attributes of four zero-fat oil vinegar liquid seasonings. The consumer preferences of the overall flavor were evaluated through 9-point hedonic tests. The intensity perception of the attributes of the zero-fat oil vinegar liquid seasoning were evaluated by 5-point just-about-right (5-JAR) method. Results The Luoshenhua flavor performed best for consumer overall likings, followed by the Sichuan style spicy flavor zero-fat oil vinegar liquid seasoning. The fruity flavor and the Japanese style original flavor got the lowest acceptance scores among the four zero-fat oil vinegar liquid seasoning. According to the JAR analysis, the attributes needed to be adjusted such as the strength of the color, aroma, acidity, saltiness, and aftertaste of the Japanese original flavor and fruity flavor zero-fat oil vinegar liquid seasoning samples, and the flavor of Luoshenhua and Sichuan style spicy samples needed to be fine-tuned for individual attributes. Conclusion By utilizing quantitative descriptive analysis and consumer sensory testing, the sensory attributes of products can be combined with consumer preferences, which could effectively reflect the consumer acceptance of each attributes of the product. This provided guidance and reference for new product development and formula adjustment.

Objective To establish a method for determining the volatile components of lubricating oil mixed in edible oil by headspace-gas chromatography-mass spectrometry. Methods The 1.0 g oil sample was directly taken into a 10 mL headspace bottle, then capped and sealed. Headspace-gas chromatography-mass spectrometry analysis was carried out at 90 ℃ equilibration for 20 min. Qualitative analysis was performed on 5 kinds of compounds: 4-methyl-2-pentanol, isooctanol, nonane, undecane and dodecane, while quantitative analysis was performed on isooctanol, nonane, undecane, and dodecane. Results The 4 kinds of quantitative compounds showed good linear relationships within the range of 0.5-8.0 mg/kg, and the correlation coefficients were all above 0.9980. Soybean oil was used as the sample for the spike recovery experiment. The recoveries of nonane, isooctanol, undecane, dodecane were 91.5%-98.2%, 81.9%-92.7%, 92.8%-94.6%, 89.3%-93.7% respectively and the relative standard deviations were all less than 10%. In the 5 kinds of edible oils: Soybean oil, peanut oil, rapeseed oil, corn oil and sunflower seed oil, the limits of detection of nonane, isooctanol, undecane, dodecane were 0.006-0.013 mg/kg, 0.016-0.045 mg/kg, 0.011-0.020 mg/kg, 0.020-0.036 mg/kg respectively. Conclusion This method has the advantages of simple operation and rapid detection, and does not have high requirements for the instrument, which can be carried out in general laboratories, and is suitable for the screening of trace lubricating oil contamination in edible oil.

Postbiotics refer to microecological preparations made from inactivated microbial cells (dead bacterial bodies), cell lysates and fermentation metabolites, which are beneficial to the health of the host. They have attracted much attention in the fields of food and medicine due to their various biological functions such as improving intestinal health, antibacterial, anticancer and immune enhancement. The preparation of postbiotics mainly includes several steps such as fermentation, inactivation and bacterial cell disruption. The choice of fermentation strains and different inactivation methods can affect the activity of postbiotics. The active substances in postbiotics mainly include teichoic acid, proteins, peptides, short-chain fatty acids, exopolysaccharides, organic acids, etc. This paper summarized the definition, preparation methods, main components and active functions of postbiotics in combination with the research progress at home and abroad. It focused on elucidating the latest research results of postbiotics in maintaining intestinal health, enhancing immune function, and maintaining oral health, and reviewed the application progress of postbiotics in the fields of drugs, food and food preservation. At the same time, it analyzed the challenges of postbiotics in the application of the health industry from aspects such as production, product standardization, and regulatory and evaluation systems. This review aims to provide references for the development of postbiotics-related functional products and for innovation in research and application in the field of human health.

Objective To investigate the potential of Cornus officinalis extract (COE) to repair skin damage caused by ultraviolet-B (UVB) exposure and to elucidate the underlying mechanisms involved. Methods By detecting the expression of UVB induced matrix metalloproteinases (MMPs) and pro-inflammatory cytokines in human keratinocytes cells (HaCaT), the photoprotective effect of COE was evaluated, and its antioxidant enzyme activity and collagen content were assessed. After exposure of mouse hairless skin to UVB radiation, extracts were applied topically and epidermal thickness, skin water content and collagen mRNA expression were determined. Results Under UVB irradiation (354.128 mJ/cm²), 1 mg/mL COE significantly enhanced antioxidant enzyme activity and significantly reduced the expression of pro-inflammatory cytokines prostaglandin E2, interleukin-1 α, and interleukin-6; simultaneously reduced the expression of MMPs; the collagen content significantly increased, with the expression levels of type I collagen and type III collagen proteins increasing by 13% and 75%, respectively. In addition, COE could alleviate the thickening of mouse skin epidermis and loss of collagen caused by UVB radiation. Meanwhile, COE treatment reduced the content of malondialdehyde (MDA) by 69%, and increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) by 27% and 234%, respectively. Analysis of mRNA expression in mouse epidermis showed that treatment with COE resulted in a decrease in mRNA expression levels of Mmp1a and Mmp3, while mRNA levels of Col1a1 and Col3a1 increased. Conclusion COE can improve skin damage caused by UVB radiation. This improvement was associated with increased activity of antioxidant enzymes in cells, as well as reduced expression of pro-inflammatory cytokines and MMPs. The aim of this study is to further investigate the photoprotective potential of Cornus officinalis against UVB induced skin damage through mouse and cell models, and elucidate its potential mechanisms, providing a theoretical basis for the treatment of skin diseases caused by UVB photoaging and the development of new drugs from Cornus officinalis.

Objective To explore the effects of different drying methods on the physicochemical characteristics and volatile aroma components of Amomum tsaoko. Methods The fresh fruit of Amomum tsaoko in Nujiang Prefecture was used as the raw material, and 6 kinds of drying methods commonly used in Nujiang Prefecture were used to dry it. The physical and chemical indexes such as color and volatile oil content of Amomum tsaoko were detected, and the volatile aroma components were analyzed by gas chromatography-mass spectrometry (GC-MS). Results The color difference and volatile oil content of Amomum tsaoko dried by different drying methods were significantly different. The L^*, a^* and b^* of Amomum tsaoko dried by air energy heat pump drying and high efficiency electric energy drying were higher, suggesting that the color of Amomum tsaoko was bright brown red and the quality was high. The volatile oil content was (1.04±0.07)-(1.29±0.07) mL/100 g. The volatile oil content of natural sun drying, air energy heat pump drying and high efficiency electric energy drying was relatively high. The composition of volatile aroma substances in Amomum tsaoko dried by different drying methods had both similarities and differences. There were 19 kinds of common substances, and the relative content of most common substances was significantly different. There were 13 kinds of main volatile aroma components (relative content≥3%), and the common components were eucalyptol, trans-nerolidol, P-propylbenzaldehyde and (Z) -citral, and their relative contents had great difference. The relative content of aldehydes and alcohols in the volatile aroma components of Amomum tsaoko was 82.75%-95.69%. The relative content of aldehydes in Amomum tsaoko obtained by biomass hot air drying was the highest, and the alcohols in other drying methods were the highest. Conclusion Therefore, different drying methods have great influence on the physical and chemical characteristics and aroma of Amomum tsaoko. The color of Amomum tsaoko is different, and the aroma and flavor of Amomum tsaoko are significantly different.

Germinated brown rice, as a functional food ingredient, is widely used in food processing. Germinated brown rice is rich in nutrients, including γ-aminobutyric acid, γ-glutamine, dietary fiber, polysaccharides, glutathione, inositol, and octacosanol, among other bioactive substances. Germinated brown rice has a variety of physiological effects, such as anti-oxidation, lowering blood lipids, lowering blood pressure, preventing diabetes, preventing and treating cancer; it also has physiological functions such as improving memory, preventing senile dementia, sobering up, regulating emotions, improving skin, and enhancing gut microbiota. The staple food products processed with germinated brown rice as raw materials include Mantou, rice, noodles, bread, biscuits, etc. They can also be processed into germinated brown rice tea, fermented drinks, brown rice wine and other drinks; it can also be processed into germinated brown rice noodles, brown rice porridge, brown rice cake, brown rice vinegar and other foods. By improving the production technology of germinated brown rice, developing distinctive germinated brown rice food, the industrialization process can be accelerated. This article reviewed the nutritional characteristics, bioactive substances, physiological functions, and application research progress of germinated brown rice in the food industry, in order to provide reference for the promotion and application of germinated brown rice.

Objective To investigate the serotype distribution and antibiotic resistance characteristics of Salmonella isolated from retail poultry and pork meat in Shanghai. Methods The 109 Salmonella strains isolates from retail chicken meat and pork meat in Shanghai in 2021—2022 were collected, and serotyped by serum agglutination method. The antibiotic susceptibility of 7 classes of 14 kinds of antibacterial drugs was determined by microbroth dilution method, and the antibiotic resistance genes were analyzed by whole genome sequencing. Results A total of 22 serotypes were identified in the 109 Salmonella strains, with the Corvallis serotype being the predominant one in retail poultry chicken meat and the London serotype being the predominant one in pork meat. The 96.3% of the isolates strains were resistant to antibiotics, with the highest resistance rates to tetracycline, ampicillin, chloromycetin, and cotrimoxazole. Multi-drug resistant isolates accounted for 61.4% of all isolates, with the highest resistance to 7 classes of 12 antibiotics. All isolates were found to harbor resistance genes, with a total of 68 resistance genes identified. Conclusion The serotype of Salmonella isolated from retail poultry and pork meat in Shanghai in 2021—2022 is complex, with a high overall level of resistance and severe multi-resistance. The isolates carry multiple resistance genes, and the drug resistance is correlated with the resistance genes they carried. Continuous monitoring of foodborne Salmonella and in-depth research on important resistance mechanisms and transmission mechanisms are of great significance for ensuring food safety and guiding clinical drug use in China.

Objective To evaluate the degradation dynamics of the combined use of bifenazate and etoxazole on Vigna unguiculata and assess the dietary exposure risks for different population groups. Methods Bifenazate (sum of bifenazate and bifenazate-diazene) in samples of Vigna unguiculata collected from eight regions of China were detected by liquid chromatography-tandem mass spectrometry. Dietary exposure risk assessment was conducted based on the test results, dietary consumption data and body weight data of different population groups in China. Results The dissipation behaviors of bifenazate in Vigna unguiculata from Shandong, Anhui, Hunan and Guangxi all did not follow first-order kinetics. The dissipation behaviors of etoxazole in Vigna unguiculata from Shandong, Anhui, Hunan, and Guangxi followed first-order kinetics, and their half-lives were 1.93-2.54 d. Using a suspension concentrate containing 45% bifenazate and etoxazole with 8 mL formulation per mu (Chinese acre) to control red mites on Vigna unguiculata, spraying once, at the harvest interval of 10 d, terminal concentrations of bifenazate and etoxazole in Vigna unguiculata were <0.0100 mg/kg and <0.0020-0.0042 mg/kg, respectively. The contribution rate of the long-term dietary exposure risk of these 2 kinds of pesticides were all lower than 100% for different population groups, indicating that there was no unacceptable risk. Conclusion 45% bifenazate·etoxazole suspension concentrate is applied at a dosage of 8 mL per mu for controlling spider mites on Vigna unguiculata, with one spray application and a recommended pre-harvest interval of 10 days.