Objective To observe the test results and substantial impact of real-time fluorescence quantitative PCR detection technology in detecting hepatitis B virus DNA. Methods 1500 patients with hepatitis B from January 2023 to December 2023 were selected for the study data, and all of them were detected by serological markers and real-time fluorescent quantitative PCR. The control standard was the clinical diagnosis results, and the comparison index was the DNA quantitative detection results. Results Among the 1500 confirmed hepatitis B patients, real-time fluorescence quantitative PCR technology detected hepatitis B virus DNA quantification results, which showed that the viral load of 1380 patients (92.00%) could be clearly quantified, while the serological marker method could only clearly quantify the viral load of 1260 patients (84.00%). In addition to technology, factors that may affect the final test results include laboratory operations, sample and nucleic acid extraction, and storage at multiple stages. Conclusion Real time fluorescence quantitative PCR technology has higher sensitivity and accuracy compared to traditional serum blood marker detection methods, and is more suitable for modern laboratory medicine.

Objective To solve the zero drift problem of Coriolis mass flowmeter. Methods The zero calibration method based on Prolink industrial control software was used to measure and zero the CMF mass flowmeter, and data on indication error and repeatability were obtained. Results Before zeroing, the reading error of the Coriolis mass flowmeter was measured to be -0.85%, and it was calculated that there was zero drift. After zero calibration, the indication error of the flowmeter is -0.12%, and the measurement performance meets the requirements of the accuracy level. Conclusion After using Prolink industrial control software to adjust the zero value of the flowmeter, the influence of zero drift on the phase difference offset of the flowmeter can be eliminated, thereby improving the measurement accuracy of the flowmeter.

Objective To study the killing effect of glycine combined with iodophor disinfectant on drug-resistant Staphylococcus aureus. Methods Neutralizing agent identification and suspension quantitative killing experiment were used to observe the effect of glycine compound combined with iodophor disinfectant in killing drug-resistant Staphylococcus aureus. Results Iodophor can kill Staphylococcus aureus, with a dilution sterilization efficiency of 63.7%. At the same time, the addition of 4% glycine and a synergistic iodophor disinfectant found a sterilization rate of 79.6%. When killing Staphylococcus aureus in suspension, there was a significant promotion of sterilization effect, which was significantly different from the group with only iodophor$\left({P <{0.01}}\right)$. Conclusion Glycine compounds can significantly enhance the killing effect of iodine on Staphylococcus aureus and increase the sensitivity of bacteria to disinfectants.

Listeria monocytogenes (LM) is a foodborne pathogen that causes diseases with high rates of lethality, and its contamination is particularly problematic in ready-to-eat meat products. With the accelerated pace of modern life and the rapid development of society, the demand for ready-to-eat food has been rising, and the risk of contamination of ready-to-eat food by LM has increased. This not only poses a potential threat to the health and safety of consumers, but also has the potential to trigger significant economic losses. This paper comprehensively analyzed the outbreak cases of LM in ready-to-eat meat products, the relevant laws and regulations of ready-to-eat foods in specific countries, and the current biological control measures. Through the in-depth discussion of relevant elements, the aim was to comprehensively describe the control strategy of LM in ready-to-eat foods, and identified potential risks and challenges, so as to provide scientific guidance for the control of LM in the food industry.

Objective To established an analytical method for indirectdetermination of xylo-oligosaccharides in high gelatinization-bakedfoods by high performance liquid chromatography with refractive indexdetector. Methods After degreased with petroleum ether, the samples wereextracted with 20% ethanol solution, and macromolecular sugars such asdextrin and starch were precipitated with 68% ethanol solution. Thesugars in the extraction solution were hydrolyzed into monosaccharidesby diluted sulfuric acid, the solution before and after hydrolysis wasseparated by amide column, detected by refractive index detector, andquantified by external standard method. The product between thedifference of xylose before and after hydrolysis and the averageconversion coefficient of xylo-oligosaccharides and xylose was thexylo-oligosaccharides. Results When the xylose was ${0.25}\sim {5.00}\mathrm{{mg}}/\mathrm{{mL}}$ ,there was a good linear relationship between peak area and concentration $\left({r ={0.9998}}\right)$ . Therecovery rates ranged from 92.0% to 95.8%, the relative standarddeviations (RSDs) were ${1.8}\%\sim {4.0}\%$ in highgelatinization-baked foods. The limit of detection and limit ofquantization of xylo-oligosaccharides were ${0.03}\mathrm{\;g}/{100}\mathrm{\;g},{0.1}\mathrm{\;g}/{100}\mathrm{\;g}$ respectively. Conclusion The extraction method of low concentrationethanol solution is feasible and specific. The method avoided the impactof high gelatinization on the low extraction efficiency and measurementresults. It can determine xylo-oligosaccharides in highgelatinization-baked foods accurately and quickly.

Food contaminants pose a serious challenge to public health and the food industry, and there is an urgent need to develop more advanced detection techniques and updated prevention strategies. Although the traditional culture technology has played an important role in the detection of food contaminants, there are obvious limitations in the detection speed, sensitivity and specificity. With the increasing expansion of global food trade, the growing production scale of food enterprises, and the increasing attention of the public to food safety, food safety has become a hot topic around the world. Food contaminants are mainly divided into chemical and biological categories, including but not limited to pesticide and veterinary drug residues, heavy metal ions, abused food additives, foodborne pathogens and mycotoxins. In recent years, with the rapid development of cutting-edge technologies such as molecular biology technology, biosensors, nanotechnology and advanced imaging technology, these innovative methods are gradually overcoming the limitations of traditional detection methods. This paper discussed the principles, advantages and limitations of these innovative detection technologies in depth, and reviewed the latest research progress in the field of food detection. By comparing different detection methods, this paper aims to provide guidance for selecting suitable detection technology to achieve rapid and accurate detection and analysis of food contaminants.

Objective To evaluate the uncertainty in the determinationof thiamethoxam content in corn by high-performance liquidchromatography-tandem mass spectrometry. Methods According to GB/T20770-2008 Determination of 486 Pesticides and Related ChemicalsResidues in Grains-Liquid Chromatography-Tandem Mass Spectrometrymethod, by establishing a mathematical model, the sources of uncertaintywere analyzed and the effects of different sources were measured andcalculated. Results Forthe corn samples with a mass fraction of ${0.282}\mathrm{{mg}}/\mathrm{{kg}}$ ofthiamethoxam, the extended uncertainty was ${0.041}\mathrm{{mg}}/\mathrm{{kg}}\left({P={95}\%, k = 2}\right)$ . Conclusion The main source ofuncertainty affecting the test result is the determination of samplesolution.

Objective To improve and establish a molecular fluorescencespectrophotometry method for determining the content of vitamin ${\mathrm{B}}_{2}$ in animal derived foods.Methods Using pork belly, chicken, pig liver, and cow kidney as researchobjects, and referring to GB 5009.85-2016 National Standard of FoodSafety-Determination of Vitamin ${B}_{2}$ in Foods, further simplified theexperimental process, optimize experimental conditions, analyzed variousfactors that affect the results during the detection process, such as $\mathrm{{pH}}$ , light intensity, andthe effect of sodium hydrosulfite on fluorescence quenching, improvedthe accuracy of the method for determining vitamin ${\mathrm{B}}_{2}$ in animal derived foods.Results The maximum fluorescence intensity was determined at pH 6.5. Asthe light intensity increased and the light duration increased, thefluorescence intensity gradually decreased. After 5 hours, vitamin ${\mathrm{B}}_{2}$ basically decomposedcompletely. Vitamin ${\mathrm{B}}_{2}$ exhibited good linearitywithin the range of $0 \sim {10\mu}\mathrm{g}$ , with ${r}^{2}={0.9993}$ ; the limit of detection was ${0.004}\mathrm{{mg}}/{100}\mathrm{\;g}$ ,and the limit of quantification was ${0.02}\mathrm{{mg}}/{100}\mathrm{\;g}$ .The recovery rates for spiking ranged from ${90}\%\sim {100}\%$ . The relativestandard deviation of parallel sample determination results was lessthan 6%. Conclusion This method is accurate, simple in equipment, andcost-effective, and can meet the needs of grassroots laboratories forthe determination of vitamin ${\mathrm{B}}_{2}$ in animal derivedfoods.

Objective To evaluate of uncertainty in the determination of residual cyclopropamide in animal food by high-performance liquid chromatography. Methods The sample was repeatedly extracted by the mixture of Trichloroacetic acid and acetonitrile. The supernatant was degreased with n-hexane, and then concentrated by rotating evaporation in a water bath. The mixture of trichloroacetic acid and acetonitrile was redissolved, and then purified by a mixed cation exchange solid phase extraction column. After separation by an amino chromatographic column, acetonitrile water was used as the mobile phase for isocratic elution. The residue of cyclopromazine in animal food was quantitatively determined by diode array detector and external standard method. According to the JJF 1135-2005 Chemical Analysis Measurement Uncertainty Assessment and JJF 1059.1-2012 Measurement Uncertainty Assessment and Representation, the uncertaintygenerated during the entiretesting process includes weighing, standard, standard working curve formulation, standard curve fitting, sample measurement repeatability, instrument and standard recovery rate, and the uncertainty introduced by each factor is calculated, and finally theexpansionuncertainty is obtained. Results When the detection result of cyromazine in chicken was 19.8 µg/kg, with an expanded uncertainty of 3.2 µg/kg. Conclusion The main factors affecting uncertainty are the determination of standard, samples, the preparation of standard curves and the fitting of standard curves.

The issue of food quality and safety is a major issue related to the national economy and people's livelihood, and it is also a livelihood issue that the Chinese people are increasingly concerned about. Grain collection and storage enterprises shall establish a quality and safety traceability system to record and save food quality and safety information objectively, effectively and truly. This article aimed to understand the construction and operation status of the traceability system for grain storage enterprises through on-site research, document review, and conference communication. On the basis of drawing on the experience of traceability systems for grain storage enterprises at home and abroad, and in accordance with relevant laws, regulations, and standards such as the Food safety law of the People's Republic of China, the Opinions of the General Office of the State Council on Accelerating the Construction of Important Product Traceability Systems (State Council Office [2015] No.95), and the Opinions of the Food and Drug Administration on Promoting the Improvement of Traceability Systems for Food and Drug Manufacturers and Operators (Food and Drug Administration [2016] No.122), a quality and safety traceability system for grain storage enterprises was formulated, so as torealize the traceability of grain quality and safety in the forward direction, traceability in the reverse direction, and risk control. When quality and safety problems occur, products could be recalled, the causes could be investigated, and responsibilities could be pursued. Intended to provide reference suggestions for improving the quality and safety traceability system construction of grain storage enterprises, to ensure grain quality and safety, and to provide support for supervision.