Objective To establish a method for the determination of 17α-estradiol and 17β-estradiol in aquatic products by QuEChERS combined with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods The sample was extracted with water-acetonitrile (2:8, V:V), purified with N-propylethylenediamine, C₁₈ and neutral alumina, blown to dryness with nitrogen, and then reconstituted with water-acetonitrile (8:2, V:V). The sample solution was analyzed using water and acetonitrile (both containing 5 mmol/L ammonia) as mobile phase, separated by C₁₈ chromatographic column, scanned and detected in multiple reaction monitoring (MRM) mode, and quantified by external standard method. Results The results showed that 17α-estradiol and 17β-estradiol showed a good linear relationship in the concentration ranges of 5 to 200 μg/L, and the correlation coefficients were 0.9998 and 0.9985, respectively. The average recoveries at three spiked concentration levels varied from 66.5% to 101.1% with relative standard deviations of 0.62% to 10.17%. The limit of detection was 0.85-0.90 μg/kg, and the limit of quantitation was 2.1-2.4 μg/kg. Conclusion This method is simple, fast, sensitive and accurate, suitable for qualitative and quantitative analysis of 17α-estradiol and 17β-estradiol in aquatic products such as fish, shrimp, crabs and shellfish.

With the growing awareness of public health, cereal and coarse grain foods, owing to their superior nutritional value and health-promoting functions, have increasingly become a critical dietary option for individuals with chronic diseases and are gaining favor among broader consumer groups. Consequently, the application of grains and cereals in baking premixes holds significant importance. This article reviewed the nutritional composition and efficacy of cereal and coarse grain premixed powders, examined their specific forms in food premixes, and emphasized the research progress regarding the food quality of cereal and coarse grain premixed powder products. Optimizing the particle size of coarse grain powders, adjusting formula compositions, and incorporating compound fermentation agents can effectively enhance the product quality and nutritional value of cereal and coarse grain baking premixed powders. Simultaneously, these methods improve the sensory experience of the final product, aligning it more closely with emerging trends in future food development. Grains and cereals, as potential daily dietary staples, possess the capability to comprehensively enhance food in terms of appearance, functionality, convenience and sensory enjoyment when formulated as ready-mixed powders. They are anticipated to become one of the key directions for the future development of the food industry. This article offers a theoretical foundation and technical guidance for the healthy and diversified advancement of the baking industry.

Objective To investigate the effects of repeated freeze-thaw cycles, induced by temperature fluctuations during cold chain circulation, on the quality deterioration of pre-prepared grilled fish. Methods An accelerated deterioration model was established through extreme treatment to examine the effects of up to 8 freeze-thaw cycles on microstructure, texture properties, pH, color parameters and lipid oxidation. Correlation analysis was conducted to identify the primary factors contributing to quality degradation. Results As the number of freeze-thaw cycles increased, muscle tissue damage intensified, myofibril structures fractured, and hardness, elasticity, chewiness and shear force declined, while adhesiveness increased. The pH value showed a decreasing-then-increasing trend. Overall, the lightness value (L^*) progressively decreased, while the redness (a^*) and yellowness (b^*) values continuously increased. The thiobarbituric acid reactive substances (TBARS) value significantly increased from 0.28 mg/kg to 2.00 mg/kg (P<0.05). After 6 cycles, the total volatile basic nitrogen (TVB-N) content exceeded the national safety limit for consumption (27.43 mg/100 g, national standard limit≤25 mg/100 g). Conclusion The quality of pre-cooked grilled fish significantly deteriorates during distribution, and the damage becomes more severe with increasing freeze-thaw cycles. After more than 5 cycles, the product is no longer suitable for consumption. These findings provide a scientific basis for quality control strategies in the cold chain logistics of pre-prepared aquatic products.

Objective To analyze the overall situation of food safety supervision and sampling inspection in an eastern coastal city from 2021 to 2024 and the main food safety issues. Methods The municipal level food safety supervision and sampling inspection data publicly disclosed by the eastern coastal city from 2021 to 2024 were aggregated. The overall inspection situation was analyzed using the dynamic trend of non-compliance rates, and the distribution characteristics of non-compliant samples across dimensions such as testing items, food categories, packaging factors and locally produced foods were stratified to identify the main factors affecting regional food safety. Results Over the past 4 years, a total of 34545 batches were inspected at the municipal level, with an overall non-compliance rate of 2.20%. The annual non-compliance rates fluctuated, showed a narrowing trend in amplitude. The highest non-compliance rates were observed in fruit products (5.83%), edible agricultural products (3.71%) and aquatic products (2.58%). In industrial processed foods, the non-compliance rates of bulk (2.01%) and pre-packaged (0.78%) showed a significant difference. The non-compliance rate of locally produced foods decreased fluctuatingly. Among them, 12 major categories (38.71%) showed no non-compliance for 4 consecutive years, while 13 categories (41.94%) exhibited a decline in non-compliance rates. Conclusion The overall status of food safety in this city showed a positive trend, with particularly quality improvement of locally produced foods. However, there were still risks in edible agricultural products and bulk foods. The regulators should pay more attention to them.

Objective To investigate the current situation of cadmium contamination in food and explore the dietary exposure risk of cadmium in the daily diet of residents in the southeast coastal areas. Methods Random sampling was conducted in major large-scale agricultural markets, commercial supermarkets, restaurants and other places throughout the city, with common commercially available foods as the research object. A total of 1285 food samples were collected from 7 categories, including grains and their products, vegetables, aquatic animals and their products, meat products, nuts and seeds, fresh edible fungi and seasonings. Inductively coupled plasma mass spectrometry method (ICP-MS) was applied for quantitative detection of cadmium content. The single factor pollution index (P_i) and target hazard factor (THQ) were used to evaluate the quality and consumption safety of each category of samples. Results After statistical analysis, there were significant differences in cadmium content among different categories of food. In the tested samples, the total detection rate of cadmium was 54.24%, and the detection result was undetected-2.86 mg/kg. Among them, crustaceans (sea crabs, shrimp) had the highest average detection value (1.2264 mg/kg). Conclusion The dietary exposure risk assessment results of tested sample indicate THQ<1. Therefore, the cadmium contamination in this region shows a low health risk to residents.

Objective To establish a method for determination of patulin in rice bran by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods The patulin from rice bran samples were extracted with ethyl acetate, purified by a solid phase extraction cartridge, eluted with the mobile phase of 0.1% formic acid solution and acetonitrile, separated on the Luna®Omega Polar C₁₈ column (100 mm×2.1 mm, 3 μm), then analyzed in positive and negative ion mode of electrospray ionization source under multiple reaction monitoring mode, quantified by matrix matching curve external standard. Results In the range of 25.0-250.0 μg/L, the peak area of patulin was linearly correlated with the content, and the correlation coefficient (r²) was 0.9993. The limit of detection was 3.0 μg/kg, limit of quantitation was 10.0 μg/kg. Meanwhile, the average recoveries of patulin in rice bran were 86.7%-96.5% with the maximum relative standard deviations of 6.2% at the spiked concentration of 25.0, 50.0, 250.0 μg/kg. Conclusion This study establishes an efficient detection method for patulin in rice bran. This method has high precision and accuracy, and is simple to operate and has high analytical efficiency at the same time. The research results provide technical support for formulating the determination standard of patulin in rice bran and related quality control specifications.

Foodborne pathogenic bacteria are one of the main causes of foodborne illness, and pose a serious threat to global public health. At present, the detection of pathogenic bacteria in food primarily relies on conventional plate culture method and auxiliary means, such as chromogenic medium and biochemical identification. However, these methods are long-term, cumbersome and prone to false positives, making them inadequate to meet the demands of modern food safety for rapid and accurate detection. Therefore, the development of rapid and effective detection technologies is crucial for the timely detection, control and elimination of bacterial contamination. This paper took several common foodborne pathogenic bacteria, including Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, and Staphylococcus aureus, as examples to provide a detailed analysis of the principles, applications, advantages and limitations of various detection methods, and discussed the development trend of detection technology in the future. This study provides both theoretical support and practical guidance for enhancing existing detection methods and the developing new rapid detection technologies, with the goal of more effectively tackling challenges related to food safety.

Objective To investigate the effects of Tuo tea flavonoids on D-galactose-induced aging mice in delaying aging and inhibiting inflammation. Methods The anti-aging efficacy of Tuo tea flavonoids were evaluated by measuring weight change, organ index and specific indicators in serum and tissue samples of aged mice treated with Tuo tea flavonoids. Results Tuo tea flavonoids could effectively prevent weight loss caused by aging, and also had a significant effect on preventing the shrinkage of key organs such as the thymus and brain. In addition, the compound also increased the levels of total antioxidant capacity (T-AOC), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the blood and liver of aging mice, while reducing the concentrations of malondialdehyde (MDA) and nitric oxide (NO). At the same time, the levels of inflammation-related interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) cytokines in serum of aging mice were decreased. Further studies showed that in liver tissues, the expression levels of neuronal nitric oxide synthase (nNOS), endothelial nitric oxide synthase (eNOS), manganese superoxide dismutase (Mn-SOD), copper zinc superoxide dismutase (Cu/Zn-SOD) and catalase (CAT) mRNA increased. The inducible nitric oxide synthase (iNOS) showed a decreasing trend. Especially when the dose reached 100 mg/kg, the Tuo tea flavonoids showed better effects than the same dose of vitamin C. Conclusion As a natural product with potential life-prolonging function, the Tuo tea flavonoids show good biological activity.

Objective To determine the content of 27 kinds of inorganic elements in commercially available Solanum tuberosum L. in Qinzhou City and evaluate the situation of heavy metal pollution. Methods Quantitative analysis of 27 kinds of inorganic elements in Solanum tuberosum L. was conducted using the inductively coupled plasma mass spectrometry method from GB 5009.268—2016 National food safety standard—Determination of multiple elements in foods. The safety of the samples and the distribution of characteristic elements were comprehensively evaluated by combining the single-factor pollution index method, Nemerow comprehensive index method, and chemometrics based on the toxicity of the elements. Results The commercial Solanum tuberosum L. from Qinzhou City contained abundant trace elements, including the essential constants of human body such as Na (7.50-458.20 mg/kg), Mg (66.40-429.40 mg/kg), K (1620.80-7397.60 mg/kg), Ca (15.00-123.60 mg/kg); essential trace elements such as Mn (0.46-5.16 mg/kg), Fe (3.00-142.10 mg/kg), Cu (0.24-1.12 mg/kg); hazardous elements such as Pb (0-0.08 mg/kg), Cd (0-0.03 mg/kg), As (0-0.08 mg/kg), Cr (0-0.32 mg/kg). The hazardous elements Hg, Sn, Ni were not detected. The content of potentially harmful elements was low, indicating good safety. Single-factor pollution index and Nemerow comprehensive index analyses demonstrated that the single-factor pollution index values and Nemerow comprehensive index values for Pb, Cd, total Hg, total As, and Cr in all samples were less than 0.7, categorizing them as excellent grade with safe pollution levels. Principal component analysis identified Li, Al, Ti, V, Cr, Mn, Fe, As, Mg, K, Cu, Zn, Na, Ca and Sr as characteristic inorganic elements. Cluster analysis classified the samples into two major categories. Conclusion The Solanum tuberosum L. are sold in the market in that city, which has a very low content of harmful elements and a low degree of pollution, and the content does not exceed the limit requirements of GB 2762—2022 National food safety standard—Maximum levels of contaminants in foods. Therefore, all the tested Solanum tuberosum L. samples are safe food, and their growing environment is not polluted by heavy metals.