Evaluation of pesticide residues in vegetables from Mekong, Delta, Vietnam using LC-MS/MS

Purpose: To assess the levels of pesticide residues in commonly used vegetables in Vietnam as a reference for future monitoring. Methods: A total of 180 samples of six different fresh vegetables including watercress, mustard green, choy sum, daikon, okra, and yam were analyzed from Mekong Delta, Vietnam. Ten popular pesticides were evaluated using liquid chromatography-tandem mass spectrometry (LC-MS/MS) after extraction with a multi-residue method (QuEChERS method). Results: The results were assessed according to the maximum residue limit (MRL) provided by Codex for each pesticide in each commodity. Pesticide residues above the MRL were detected in 107 samples (59 %) and 63 samples (47 %) contained residues below the MRL. Multiple residues were present in 38.3% of the samples with two to five pesticides, and 0.6 % of samples were contaminated with more than five pesticide residues. Of the pesticides investigated, eight pesticides were detected, of which abamectin, alpha-cypermethrin, acetamiprid, chlorpyrifos- ethyl, chlorantraniliprole, fenobucarb, fipronil, and trichlorfon exceeded their MRLs. Pesticide residues were detected above MRLs in samples of watercress (14 samples), mustard green (24 samples), choy sum (25 samples), daikon (26 samples), and yam (18 samples). Chlorpyrifos-ethyl, and fipronil were detected in most of the vegetable samples (100% and 89.44%, respectively). Conclusion: The results indicate the occurrence of pesticide residues in commonly consumed vegetables in Vietnam. The need for the regular monitoring of pesticide residues and the sensitization of farmers to better pesticide safety practices, especially the need to adhere to recommended pre-harvest intervals is recommended

Evaluation of Pseudomonas stutzeri AM1 and Pseudomonas oleovorans ST1.1 isolated from shrimp pond sediments as probiotics for whiteleg shrimp, Litopenaeus vannamei culture

This study aimed to isolate the probiotic potential of nitrifying bacterial strains and to evaluate their effects on water quality and growth performance of the whiteleg shrimp, Litopenaeus vannamei. Based on an initial screening of 100 isolates identified from sediment samples, 12 strains could remove nitrogen compounds and two strains (Pseudomonas stutzeri AM1 and P. oleovorans ST1.1) showed highly efficient nitrogen removal ability. Within 96 h, total ammonia nitrogen (TAN) removal efficiency in the two strains was 28.0-31.6% and 21.5-24.9%, respectively. The water addition of 103 CFUmL-1 of P. stutzeri AM1 (T1) and P. oleovorans ST1.1 (T2) effectively reduced TAN, nitrite, nitrate, and total sulfide and increased the survival rate and biomass of shrimp. However, no significant differences were found between the control (T0) and treatment groups (T1 and T2) in the final weight, weight gain and specific growth rate of shrimp. Overall, P. stutzeri AM1 (T1) and P. oleovorans ST1.1 used as water supplements improved water quality and the survival rate of whiteleg shrimp

Antibiotic residues and heavy metals in pork at wet markets in Vietnam

From April 2014 to January 2015, a total of 190 fresh pork samples at wet markets were collected to produce 18 pooled samples that represent 18 studied communes in Hung Yen and Nghe An provinces. Tetracycline, fluoroquinolones, sulfonamide, chloramphenicol groups were firstly screened by ELISA and positive samples were quantified by liquid chromatography–mass spectrometry/mass spectrometry (LCMS/MS). Lead, cadmium and arsenic were determined by Atomic Absorption Spectrometer (AAS). While pooled samples for tetracycline and fluoroquinolones (0/18) were negative tested we found positive test results for sulfonamide (50%, 9/18) and chloramphenicol (16.7%, 3/18). The average residue levels were 155.5 (25.6-263.2) µg/kg for sulfadimidine, higher than Vietnamese MRL (100 µg/kg) and 0.54 (0.34- 0.76) µg/kg for chloramphenicol, which is prohibited in veterinary drugs in Vietnam. Regarding heavy metals, there were 5/18 (27.8) of pooled samples being positive for lead, while cadmium and arsenic were not detected. The average concentration of lead in pork was 74.1 (70.1-78.7) µg/kg, which was still lower than the standard level applied for lead in pork (100 µg/kg). There were no significance differences on the prevalence and concentrations of antibiotic and heavy metal residues between the two studied provinces. The results highlight the presence of sulfadimidine and chloramphenicol in pork available at wet markets. This finding is a component of an ongoing food safety project (PigRISK), which is assessing the health risks of chemical hazards in pork and developing incentive-based innovations to improve management of human and animal health risks in smallholder pig value chains in Vietnam

Exposure assessment of chemical hazards in pork meat, liver, and kidney, and health impact implication in Hung Yen and Nghe An provinces, Vietnam

Objectives This study assesses the risk of exposure to hazardous chemical residues in pork meat, liver, and kidney collected at wet markets in Nghe An and Hung Yen provinces and discusses health impact implication. Methods 514 pig feed, kidney, liver, and pork samples were pooled and qualitatively and quantitatively analyzed for tetracyclines, fluoroquinolones, sulphonamide, chloramphenicol, β-agonists, and heavy metals. We compare the results with current regulations on chemical residues and discuss health implications. Results Legal antibiotics were found in feed. Tetracycline and fluoroquinolones were not present in pork, but 11% samples were positive with sulfamethazine above maximum residue limits (MRL); 11% of packaged feed and 4% of pork pooled samples were positive for chloramphenicol, a banned substance; two feed, two liver, and one pork samples were positive for β-agonists but did not exceed current MRL; 28% of pooled samples had lead, but all were below MRL; and all samples were negative for cadmium and arsenic. Thus, the health risks due to chemical hazards in pork in Hung Yen and Nghe An seemed not as serious as what were recently communicated to the public on the mass media. Conclusions There is potential exposure to sulphonamide, chloramphenicol, and β-agonists from pork. Risk communication needs to focus on banned chemicals, while informing the public about the minimal risks associated with heavy metals

Identification and <i>α</i>-glucosidase inhibitory activity evaluation of two new coumarins derived from <i>Mansonia gagei</i> J. R. Drumm.

Five coumarins were isolated from the heartwood of Mansonia gagei, which included two newly discovered compounds, namely 11-hydroxypopulene E (1) and mansorin D (2), along with three previously identified compounds. The structures were determined through the utilisation of comprehensive spectroscopic data, ECD calculations, and a thorough comparison with existing literature data. The α-glucosidase inhibitory activities of all isolated compounds were assessed in yeast. Out of the compounds tested, compound 2 exhibited the most significant activity, displaying a percentage inhibition of 34.33% at a concentration of 200 μM.</p

Proceedings of the 5th Conference on Language Teaching and Learning

This conference proceedings contains articles on the various research ideas of the academic community and practitioners presented at the 5th Conference on Language Teaching and Learning (LTAL-2023). LTAL2023 was organized by the Ho Chi Minh City University of Food Industry, Vietnam on May 7, 2023. Conference Title: 5th Conference on Language Teaching and LearningConference Acronym: LTAL-2023Conference Date: 7 May 2023Conference Location: VietnamConference Organizers: Ho Chi Minh City University of Food Industry, Vietnam. Related Proceedings:  Proceedings of the 4th Conference on Language Teaching and Learnin