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Browsing Theses and Dissertations by Author "Kgatla, T. E."
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Item Embargo An investigation of hygiene practices in butcheries and the prevalence of antibiotic resistant Listeria monocytogenes in Limpopo, South Africa(2024-09-06) Siluma, Bridget; Ramashia, S. E.; Nethathe, B.; Kgatla, T. E.Listeria monocytogenes is a foodborne bacterial pathogen associated with serious public health and food safety problems. It is an intracellular microbe that causes Listeriosis, a life-threatening disease that yields to bacteremia, meningitis, and spontaneous miscarriage. This study aimed to conduct the survey and investigate the prevalence and antibiotic susceptibility of L. monocytogenes from butcheries (village & commercial) and supermarkets beef plate meat in the Vhembe district. Evaluation of meat safety practices and hygiene among different butcheries and supermarkets was conducted using a questionnaire. The prevalence of L. monocytogenes in retail beef plate meat was determined on chromogenic agar and the antibiotics susceptibility was examined from L. monocytogenes isolates using the well diffusion method. The results of this study revealed that (i) some supermarkets followed the meat safety practices and hygiene, whereas there was a combination of good and unhygienic meat handling practices identified at commercial and village butcheries (ii) L. monocytogenes were identified in high numbers however some other species of Listeria such as L. ivanovii and L. innocua were found in beef plate meat (iii) The Listeria isolates were resistant to a wide range of antibiotics used to treat human listeriosis such as ampicillin, tetracycline and nalidixic acid in large numbers while a few of the isolates were susceptible to sulphamethoxazole and intermediary responsive to oxytetracycline and chlortetracycline. The findings from this study concluded that some supermarkets follow the safety procedures while commercial and village butcheries do not follow the procedures and regulations, furthermore, the prevalence of the pathogenic L. monocytogenes may harm the communities around Vhembe district. Moreover, treatment in case of an outbreak may become burdensome as the pathogen may be resistant to antimicrobial treatment. It is recommended that intervention through training on food safety to improve the hygienic practices of meat handling along the beef supply chain, more especially within commercial and village butcheries be conducted, also L. monocytogenes control measures from relevant authorities need to be put in place, meat must be prepared adequately, and antibiotics must be utilized appropriately. In addition, conducting molecular research on Listeria species to determine the virulence genes present in L. monocytogenes isolated from retail beef, to keep track of the type of strains of Listeria that may be circulating in the Vhembe district is recommended.Item Open Access Effects of mineral ions on yeast performance under very high gravity beer fermentation(2015-02-11) Udeh, Henry Okwudili; Kgatla, T. E.; Jideani, A. I. O.Item Open Access Extraction and characterization of pectin from prickly pear (Opuntia spp.) peel(2020-08-24) Lekhuleni, Isobel Lerato Gosh; Jideani, A. I. O.; Kgatla, T. E.; Mashau, M. E.The study aimed to determine the physicochemical properties, extract and characterise pectin from three varieties (green, purple and orange) of prickly pear (Opuntia spp) fruit peel. Research samples were collected from Bothlokwa Mphakane village in Limpopo province of South Africa. The experimental design for this study was randomized complete block design and each treatment was conducted in triplicate. Pectin was extracted using sulphuric acid at four different pH levels (1, 2, 3 & 4) and microwave power levels (low, medium & high). The characterisation of extracted pectin was done by calculating the ash, moisture, equivalent weight, anhydrouronic acid, methoxyl content, and degree of esterification. Functional groups present in extracted and commercial pectin were investigated for similarities using Fourier Transform Infrared Spectroscopy. The yield of pectin for purple ranged from 2.9% to 13.8%, orange from 1.4% to 9.8% and from 2.3% to 10.0% for green prickly pear peel. A decrease in pH resulted in an increased pectin yield and an increase in microwave power level increased the pectin yield. Maximum yields of 13.8% on purple, 10.0% on green and 9.8% on orange were obtained at pH 1.0 and medium power level. The best condition for extraction using sulphuric acid was at a medium power level and pH 1.0. The pectins obtained were compared against each other in terms of yield, physicochemical characteristics and chemical structure. The ash content of the extracted pectin was significantly higher at 25.16 ± 0.69, 34.26 ± 1.92 and 36.30 ± 1.07, however the pectin showed lower moisture content and equivalent weight. The methoxyl contents were 2.28 ± 0.26, 2.38 ± 0.21 and 3.86 ±0.31, anhydrouronic acid contents were 25.58 ± 2.03, 25.93 ± 2.35 and 38.84 ± 2.29, and degree of esterification were 49.87 ± 0.17, 50.63 ± 4.76 and 56.39 ± 1.60 across the orange, purple and green varieties, respectively. The prickly pear peel pectin spectra exhibited similarities in its absorption pattern to that of commercial citrus pectin. Therefore, the extraction of pectin from prickly pear peels is feasible in viewpoint of yield and quality, and that the pectin has potential for substitution of citrus pectin in the food processing industry.