Browsing by Author "Mgonja, F."

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The effect of cold storage and cooking procedures on the levels of oxytetracycline residues in beef from Dodoma region, Tanzania
(Sokoine University of Agriculture, 2018) Mgonja, F.
Worldwide, there is an increased use of antimicrobial drugs due to occurrence of diseases of human and animals. The general objective was to study the effect of cooking procedures and cold storage on the levels of Oxytetracycline (OTC) residues in beef in Tanzania. The study used a cross-sectional research design whereby both quantitative and qualitative data were collected from Dodoma region, Tanzania. The household survey was conducted to assess knowledge, attitude and practice on beef consumption among 254 residents. The results show that community based health education and promotion of proper antimicrobial use in animals and preventing drug residues is highly recommended to this population. Beef samples were also analyzed by using High Performance Liquid Chromatography Mass-Spectrometry (HPLC-MS). The quantitative data were analyzed using the IBM Statistical Package for Social Science (SPSS) software version 20 and Epi info version 7. A simple and sensitive method for the detection of OTC levels in ready-to- eat beef by HPLC-MS was modified and validated and used for beef analysis in this study. The advantages of the modified method were cleaning by Supelclean ENVI-carb active coal is cheaper compared to solid phase extraction and samples drying using a stream of liquid nitrogen is cheaper and more than six samples can be dried at a time. For the raw beef, the results indicate that the mean concentration level of OTC was very low (0.69 ± 0.09 ng/g). The boiled and barbecued beef, the mean concentration was 69.4 ±41.93 ng/g and 69.40±38.91 ng/g, respectively. The results indicate that one should not count on heat- treatment to eliminate residues of OTC from beef. The effect of the cold storage on the concentration of OTC residues in beef stored at -20 °C for 60 and 120 days showed that the mean concentration of OTC residues before freezing was 191.71 ± 90.21 ng/g. The mean concentration of OTC after freezing at -20 oC for 60 and 120 days were 166.40 ± 86.49 ng/g and 133.50 ± 83.24 ng/g respectively. These results revealed a significant (p<0.05) reduction of OTC residues of 30% after 60 days and 65% after 120 days of freezing at -20 °C.
Effect of freezing on stability of oxytetracycline residues in beef from Dodoma region, Tanzania
(Tanzania Veterinary Associatian Proceedings, 2017-12-05) Mgonja, F.
The aim of this study was to determine the effect of freezing on the concentration of oxytetracycline (OTC) residues in beef samples stored at -20 °C (core beef temperature -12 °C and below) for 60 and 120 days. A total of 60 fresh beef samples were randomly obtained from cattle slaughterhouses and butcher shops in district in Dodoma region in Tanzania. The OTC residues were determined using high performance liquid chromatography (HPLC) with a diode array detector (DAD). Results showed that the mean concentration of OTC residues in 16 positive samples before freezing was 191.71 ± 90.21 ng/g. The mean concentration of OTC after freezing at -20 °C for 60 and 120 days were 166.40 ± 86.49 ng/g and 133.50 ± 83.24 ng/g respectively. These results revealed a significant (p<0.05) reduction of OTC residues of 30% after 60 days and 65% after 120 days of freezing at -20 °C. The percentage reduction of OTC residues was not dependent on the initial concentration or the freezing process but was rather due to unknown time dependent individual beef sample factors. It is concluded that. despite OTC levels in beef decreasing due to non-freezing factors. any residues significantly above Maximum Residues Level (MRL) may not be expected to reduce to acceptable levels as a result of freezing.
Effect of heat treatment on oxytetracycline residues in beef
(American Journal of Research Communication, 2017) Mgonja, F.; Mosha, R.; Mabiki, F.; Choongo, K.
Literature about drug residues is mainly related to their concentrations in uncooked food. The aim of this study was to assess the effects of barbecuing and boiling treatments on the concentration of oxytetracycline (OTC) in beef samples collected from different districts in Dodoma region, Tanzania. The beef samples were boiled for 30 minutes or barbecued for 20 minutes. The OTC content was measured in raw and heated samples by using high performance liquid chromatography (HPLC). The mean concentration of OTC for boiled and barbecued beef samples was 69.45 ± 41.93 ng/g and 69.40 ± 38.91 ng/g, respectively. Both the boiling and barbecuing procedures significantly decreased the OTC levels in beef (p<0.05), and the boiling procedure had the highest influence on reducing OTC concentration. The OTC concentrations after the heating treatments were below the maximum acceptable residue limits (MRL). The results of this study indicate that the occurrence of violative levels of drug residues in raw meats is decreased by heating. Therefore, the occurrence of violative levels of drug residues in the food may be prevented by the heating process.
Knowledge, attitude and practice in relation to antimicrobial residues in beef among residents in Dodoma Region
(AJOL, 2020) Mgonja, F.; Mabiki, F.; Choongo, K.; Mosha, R.
The safety of food of animal origin is of concern in the developing countries. Some of the antimicrobial agents that are used for the treatment of animal diseases seem to occur in the animal products. The knowledge, attitude and practice in relation to oxytetracycline (OTC) residues in beef among residents in Dodoma Region, Tanzania were evaluated. A cross sectional study included interviewing 254 randomly chosen respondents was conducted. Fifty two percent of the respondents were not aware of drug residues, 57% never heard about drug residues in food of animal origin such as milk and meat, 35% know residues can be harmful to human and 61% did not know if animals are treated with antimicrobial drugs when they were sick. Only 27% of the respondents knew common antimicrobial agents that cause residues in animal meat and milk and were able to mention. Majority of respondents (74%) did not know any method for the prevention of antimicrobial residues. Fifty six percent of the age group of 20-35 years purchased meat from butcheries. Secondary school (68.4%) and College (52.9%) respondents purchased meat from butcheries compared to informal (23.8%) and primary (49.2%) respectively that purchased meat locally within the villages. Majority of informal (66.7%) and primary (47.6%) respondents purchased meat locally within the villages. The differences were strongly significant p< 0.0001. Women (57.1%) used one hour to prepare meat. Age group 20-35 years (88.1%) prepared meat by cooking. Age group of 36-45 years prepared meat for 1 hour and 2 hours. College respondents (68.8%) barbequing meat compared to smoking and freezing. The results in this study indicate that respondents had low knowledge and awareness on antimicrobial use and drug residues. This might be due to low level of education of respondents as majority of them had informal and primary education. Many of the drug respondents were not aware of the drug residues and did not know antibiotic residues can have effects in human health. Community based health education and promotion on antimicrobial use and preventing drug residues is highly recommended to this population.
Oxytetracycline residue levels in beef in Dodoma region, Tanzania
(African Journal of Food Science, 2017-02) Mgonja, F.; Mosha, R.; Mabiki, F.; Choongo, K.
Antibiotic residues in food of animal origin pose a threat to both human and animal’s health due to an increasing level of resistant strains of pathogenic bacteria to a wide range of antibiotic drugs. A cross- sectional study was conducted to assess the levels of oxytetracycline (OTC) residues in raw beef in Dodoma region, Tanzania. The OTC levels were determined by using liquid chromatography-mass spectrometry (LC-MS). A total of 60 beef samples were collected from various slaughterhouses and butcheries. Twenty-one out of 60 samples (35%) had OTC residues and no samples had OTC levels above the maximum allowed residues limits (200 μg/kg). The highest OTC concentration was 4.95 ng/g, while the mean concentration was 0.69 ± 0.09 ng/g. The obtained levels were not expected to induce adverse effects and the beef is safe for consumers. Though the findings indicates the meat in the market is safe for consumers, it calls for a proper management of antimicrobial drugs use for animal production as an additional advantage to consumers.
A simple and sensitive method for the detection of “Oxytetracycine” levels in ready-to-eat beef by liquid chromatography-mass spectrometry
(African Journal of Pharmacy and Pharmacology, 2016-07) Mgonja, F.; Mosha, R.; Mabiki, F.; Choongo, K.
Antimicrobial drug residues have emerged as one of the public health problems worldwide. In this study, a modified sensitive liquid chromatography mass spectrometry (LC-MS) method to detect the “Oxytetracycine” (OTC) levels in ready-to-eat beef meat in Tanzania was evaluated. Beef samples were extracted in acetonitrile in ethylenediaminetetraacetic acid (EDTA) buffer (pH 4), followed by cleaning up with Supelclean ENVI-carb active coal and a stream of nitrogen gas. The wavelength of the diode array detector (DAD) was set at 275 and 355 nm. The detection limit of the method was calculated as 18.2 ng/g and the recovery rate of OTC was 78.6%. A total of 45 ready-to-eat beef meat samples were analyzed, with 16 (35.5%) and 29 (64.5%) barbequed and boiled samples, respectively. Of the 45 samples, 35 (77.8%) samples had OTC residues while 9 (25.7%) samples had violative residue levels above the maximum residue limits recommended by the Food and Agriculture Organization and the World Health Organization. The highest concentration was 545.2 ng/g. Therefore, withdrawal period and proper use of antibiotics for animal production should be of concern as consumers are at risk of adverse effects due to consumption of unacceptable levels of drug residues and a risk of developing microbial resistance. To the best knowledge of the authors, this is the first study to evaluate LC-MS method to detect the OTC levels in ready-to-eat beef meat in Tanzania