Objective To explore and analyze the blood physiological and biochemical indicators of SPF grade SD rats of different ages and genders. Method 80 SPF grade SD rats were studied and randomly divided into four experimental groups at 4, 12, 24, and 48 weeks of age. The male to female ratio in each group was 1:1. All SD rats were analyzed for their blood physiological indicators using the XFA6030 animal blood cell analyzer; apply the Beckman Coulter AU5800 fully automated biochemical analyzer to analyze its blood biochemical indicators. Result Compared with SD rats aged 12, 24, and 48 weeks, SD rats aged 4 weeks showed significant differences in WBC, RBC, HGB, HCT, MCV, MCH, MCHC, PLT, PCT, BA #, and BA%(P<0.05), and all indicators reached their peak at 24 weeks. Among the gender differences between male and female, SD rats aged 4 weeks showed differences in BA%; 12. There were differences in WBC and RBC between 24 week old SD rats; 24 week old SD rats showed differences in BA%; 48 week old SD rats showed differences in MCH and PCT, and all differences had P values $<{0.05}$ ; Compared with 12,24, and 48 week old SD rats,4-week old SD rats showed significant differences in AST, CHOL, TP, GLU, CRE, ALT, ALP, BUN, and TG (P<0.05). Among the gender differences between male and female, 4-week old SD rats showed significant differences in CRE and ALP; There were differences in AST, CHOL, and BUN among 12 week old SD rats; There were differences in ALP between 12 week old and 24 week old SD rats, and all P values of the differences were<0.05 . Conclusion There are statistical differences in blood physiological and biochemical indicators among SD rats of the same gender but different age groups. Similarly, there are also differences in blood physiological and biochemical indicators among SD rats of the same age group but different genders.

Objective To understand the pollution levels of bromate, coliforms, pseudomonas aeruginosa, nitrite (calculated as ${\mathrm{{NO}}}_{2}$ )] of packaged drinking barreled water in Guangxi in 2022. Methods According to the type of water and test items, all pollutions were tested and judged by GB 8538-2016 “National standard for food safety Test method for drinking natural mineral water”, GB 4789.3-2016 “Food safety national standard food Microbiology test Coliform count”, GB 5009.33-2016 “National standard for food safety Determination of nitrite and nitrate,” GB 19298-2014 “Food safety national standard Packaging drinking water”, GB 2762-2017 “Food safety national standard food Pollutant limits”. Results 204 batches of packaged drinking barreled water were collected. Pseudomonas aeruginosa was deteted in 55 batches with a detection rate of 26.96%. Not a single batch exceeded permitted level of bromate, coliform or nitrite. Conclusion Most products are safe, but the pollution of Pseudomonas aeruginosa is still an outstanding problem. Enterprises should strengthen the cleaning and isinfection of pipes and barrels and standardize transportation storage to ensure product safety.

Objective To investigate the levels of veterinary drug residues in chicken and eggs in chicken production bases in Liangshan Prefecture, and evaluate the dietary exposure risk. Methods There were 353 samples of chicken and eggs collected from 17 cities in Liangshan in 2022, then the residues of quinolones and quinoline were detected and analyzed by liquid chromatography-mass spectrometry, and the exposure risk was assessed by point estimate method. Results A total of 221 pieces of chicken were sampled in 2022, among 8 types of veterinary drugs were tested with the detection rate of 25.79%, and the unqualified rate was 1.81%. Among 132 eggs, only enrofloxacin residue was detected, the detection rate was 1.52%, the unqualified rate was 1.52%. The point estimate method was used to assess the dietary risk of veterinary drug residues, and its hazard quotient was lower than 1, indicating that the veterinary drug residues have a lower risk to human health. Conclusion Veterinary drug residues can be detected in some samples of chicken and eggs in Liangshan in 2022, and the risk residues to human health is low, but the health risks of caused by some undetectable veterinary drugs cannot be ignored.

Objective To evaluate the uncertainty in determination of olive oil total migration by gas chromatography spectrometry, determine the factors affecting the accuracy of the results and provide a basis for accurate control of the olive oil total migration. Methods Gas chromatography spectrometry was used to determine the olive oil total migration, and a mathematical model was established. According to relevant rules and standards for uncertainty evaluation, the uncertainty was evaluated including repeatability, sample quality and adsorbed olive oil quality, instrument calibration, standard curve fitting, soaking area, etc. Results When The total migration of olive oil in the sample is ${4.0}\mathrm{{mg}}/{\mathrm{{dm}}}^{2}$, the expanded uncertainty was ${1.3}\mathrm{{mg}}/{\mathrm{{dm}}}^{2}\left({P={95}\%, k = 2}\right)$ . Conclusion The uncertainty of olive oil total migration mainly comes from repeatability, standard solution preparation and standard curve fitting.

Objective To study the content level of vanillin in rice and the changes of vanillin in paddy rice processing. Methods Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to determine the contents of vanillin, methyl vanillin and ethyl vanillin in 209 batches of rice from different origins; at the same time, 16 batches of rice were hulled, milled or finished, and the rice and its processed products (brown rice, standard rice or polished rice) were tested. Results Methyl vanillin and ethyl vanillin were not detected in all rice, paddy and their processed products; vanillin was all detected in 209 batches of rice, and the content values were close to the normal distribution, mainly concentrated in ${100}\sim {222\mu}\mathrm{g}/\mathrm{{kg}}$ ; vanillin was detected in rice and its processed products (brown rice, standard rice or polished rice), and the content decreases with the processing accuracy. Conclusion The possibility of naturally occurring vanillin in rice, and the source is probably rice hull; the detection of vanillin in rice is not always illegal addition, the content level of vanillin in rice and paddy rice should be continuously studied and scientifically analyzed to provide scientific evidence for the market supervision department formulating reasonably the risk reference value of rice.

Objective Isolate and identify microorganisms that cause rancidity in vacuum packed rice dumplings, thereby helping enterprises to improve product quality and control of food safety. Methods Bromocresol purple dextrose broth and cooked meat medium base were used to cultivate the acescent rice dumplings; the microorganisms were isolated and purified by scribing in Rose bengal agar, Nutrient agar, the isolated strains were identified by colony morphology observation, cell morphology observation, 16S rRNA sequence analysis, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The isolated strains were inoculated into commercial sterilized rice dumplings respectively to verify that two strains caused rancidity of rice dumplings. Results Two isolated strains, namely Lelliottia amnigena and Wickerhamomyces anomalus, caused rancidity of rice dumplings. Conclusion Lelliottia amnigena and Wickerhamomyces anomalus in vacuum-packed rice dumplings can cause rancidity.

Objective Isolate and identify microorganisms that cause rancidity in vacuum packed rice dumplings, thereby helping enterprises to improve product quality and control of food safety. Methods Bromocresol purple dextrose broth and cooked meat medium base were used to cultivate the acescent rice dumplings; the microorganisms were isolated and purified by scribing in Rose bengal agar, Nutrient agar, the isolated strains were identified by colony morphology observation, cell morphology observation, 16S rRNA sequence analysis, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The isolated strains were inoculated into commercial sterilized rice dumplings respectively to verify that two strains caused rancidity of rice dumplings. Results Two isolated strains, namely Lelliottia amnigena and Wickerhamomyces anomalus, caused rancidity of rice dumplings. Conclusion Lelliottia amnigena and Wickerhamomyces anomalus in vacuum-packed rice dumplings can cause rancidity.

Biopharmaceutical cleanroom air conditioning plays an important role in ensuring the cleanliness and stability of a clean environment. By investigating and analyzing the actual situation of clean air conditioning systems in the biopharmaceutical industry, scientific and effective methods for clean air conditioning testing and debugging are proposed, which can accurately evaluate the cleanliness and performance of clean air conditioning systems. Meanwhile, the practical application effect of this method indicates that it can improve the cleanliness and stability of clean environments.

Food re-inspection refers to food production and operation of food safety supervision and sampling inspection conclusions have objections and in accordance with the law to the market supervision and management department to submit an application for re-inspection, market supervision and management department commissioned the re-inspection of the re-inspection of the backup samples for review and inspection of the behaviour.Re-inspection is an important way for food producers and operators to safeguard their legitimate rights and interests, an important link for market supervision departments to ensure the high quality of food safety supervision work, and an important measure to ensure the relatively fair and stable operation of the market. Because the retest conclusion serves as the final conclusion Therefore, the professionalism of the re-inspection institution is particularly important in the re-inspection work. Based on the perspective of the re-inspection institution, this paper analyzes the risk points of the food re-inspection acceptance work (i. e., contract review), so that the re-inspection institution can avoid potential risks and lay a solid foundation for the smooth progress of the whole re-inspection work.

Food re-inspection refers to food production and operation of food safety supervision and sampling inspection conclusions have objections and in accordance with the law to the market supervision and management department to submit an application for re-inspection, market supervision and management department commissioned the re-inspection of the re-inspection of the backup samples for review and inspection of the behaviour.Re-inspection is an important way for food producers and operators to safeguard their legitimate rights and interests, an important link for market supervision departments to ensure the high quality of food safety supervision work, and an important measure to ensure the relatively fair and stable operation of the market. Because the retest conclusion serves as the final conclusion Therefore, the professionalism of the re-inspection institution is particularly important in the re-inspection work. Based on the perspective of the re-inspection institution, this paper analyzes the risk points of the food re-inspection acceptance work (i. e., contract review), so that the re-inspection institution can avoid potential risks and lay a solid foundation for the smooth progress of the whole re-inspection work.