https://cris.library.msu.ac.zw//handle/11408/317 2026-04-15T04:12:56Z 2026-04-15T04:12:56Z Mwazha, Milford https://cris.library.msu.ac.zw//handle/11408/3152 2022-06-27T13:49:05Z 2014-01-01T00:00:00Z

Title: A comparison of the changes in seed germination vigour with prolonged storage time between Hope and Sierra malting barley varieties at Delta Beverages, Kwekwe Maltings. Authors: Mwazha, Milford Abstract: To increase the brewing yield and efficiency, malts with high extract values, high enzymatic activities, and good modification are essential. To produce malt that meets these requirements, the barley employed must have minimal post-harvest dormancy and be able to germinate rapidly and uniformly. The aims of this study were to compare the changes in seed germination vigour trends and the general storage stability of two Zimbabwean two-row malting barley varieties (Hope and Sierra) as the post-harvest storage time increased. Two samples of these commercially grown varieties were obtained and stored under room temperature laboratory conditions. At monthly intervals the samples had their germination index and energy determined using SAB Miller standards for malting barley analysis (controlled germination in an incubator at 18oC – 21oC for 72 hours). In addition other quality parameters (nitrogen content, screenings, moisture content, water sensitivity and insect damage index) necessary to assess the storage stability of both varieties were also analyzed on monthly intervals using the same analytical standards as for germination tests. On the basis of the results obtained during the 13 months of post-harvest assessments it was found out that Hope had its Germination Index improving as storage time increased meaning that , the variety’s germination vigour improves with time. By the first month of the research the GI index for Hope was 8.7 and gradually it increased reaching 9.2 by the end of the research period. However on the other hand the seed germination vigour for Sierra gradually diminishes with time as indicated by the weak negative downhill correlation (r value = -0.24). As for other grain quality parameters (including moisture loss, insect damage index, germination energy and screenings) Hope proved to be more stable in storage than Sierra. Thus after considering germination performance and general storage stability it was concluded that Hope is a better malting barley variety than Sierra.

2014-01-01T00:00:00Z Mwazha, Milford Ngulube, Leratiloe M. https://cris.library.msu.ac.zw//handle/11408/2746 2022-06-27T13:49:05Z 2017-01-01T00:00:00Z

Title: Antimicrobial properties of tamarindus indica linn leaf extracts Authors: Ngulube, Leratiloe M. Abstract: Tamarindus indica l leaves extract was evaluated against six bacterial strains (2 Gram-positive and 4 Gram-negative) known to cause food spoilage. Functional groups of Tamarindus indica l leaves were evaluated using the Fourier transform infrared (FTIR) spectroscopy. The leaves were extracted by the Soxhlet extraction using aqueous and organic solvents (acetone, ethanol and methanol). Stock solution of the extracts was prepared by dissolving 0.8g of each extract in 2ml dimethyl sulphoxide (DMSO) to obtain a concentration of 400mg/ml and the concentration of 200mg/ml was prepared by serial doubling dilution of stock solution and 2ml of DMSO was added. Inoculum suspension was prepared by suspending appropriate colonies of the test microorganisms in sterile distilled water. The 0.5 McFarland of 1% barium chloride and 1% sulphuric acid was used to standardize the inoculum. The antimicrobial activity of the concentrated extracts was evaluated by determination of the zones of inhibition against the test microorganisms using the disc diffusion method. The results of the FTIR revealed the presence of primary and secondary amines and amides, carboxylic acid, alkenes and alkanes, fluorides, amines and aromatics. The extracts were active against both gram-positive and gram-negative bacteria. The activity of the plant extracts could have been affected by different temperature ranges, nature of the tree of freshness and dryness of the leaves. All extracts showed appreciable inhibition on the test microorganisms with the zones of inhibition ranging from 6.4 mm-19.8mm and ethanol extracts showed a broader spectrum of activity against the test microorganisms. Results obtained of this study indicate that Tamarindus indica l has broad spectrum antibacterial activity and a potential source of new classes of natural preservatives that could be useful for replacement of synthetic food grade preservatives

2017-01-01T00:00:00Z Ngulube, Leratiloe M. Moyo, Bonang B. https://cris.library.msu.ac.zw//handle/11408/2653 2022-06-27T13:49:05Z 2017-01-01T00:00:00Z

Title: Post heat treatment microbial contaminants and quantitative risk analysis of s. Aureus in sliced vacuum packed french polony Authors: Moyo, Bonang B. Abstract: Contamination of luncheon meats by bacteria has resulted in premature product spoilage and food poisoning outbreaks as well as major product recalls. A quantitative microbial assessment of air, surfaces, equipment and personnel hands (swabs), and finished product was conducted on 3 batches during separate visits at various processing stages during production of sliced vacuum packed French polony at a large meat processing plant in Zimbabwe. The aim was to determine the routes of microbial cross contamination onto French polony during slicing and packing as well as the subsequent food safety threat posed to consumers. The post-cooking environment had relatively high levels of S. aureus, yeast and molds while equipment and surfaces proved to be unhygienic as indicated by high counts of TBC and coliforms. S. aureus was the only pathogen detected in the finished product (2.04log CFU/g) and personnel hands and the counts exceeded acceptable international standards. A Quantitative Risk Assessment Model process that described steps and behaviour of S. aureus along the sliced vacuum packed French polony chain was created and the exposure of S. aureus per serving was high (> 6log CFU/serving) in over 65% of each serving and consequently the probability of illness too. Overall, there is a relatively high level of risk of microbial contamination of French polony during slicing and packing from different sources at the meat processing plant investigated and it is paramount to consolidate the quality assurance programs so as to ensure the safety of consumers of products produced at this plant.

2017-01-01T00:00:00Z Moyo, Bonang B. Nyathi, Michelle Y. https://cris.library.msu.ac.zw//handle/11408/2652 2022-06-27T13:49:05Z 2017-01-01T00:00:00Z

Title: To investigate the potential of Moringa oleifera leaf extract and broccoli (Brassica oleracea) leaf extract as Sodium sulphite replacers in preserving minced meat Authors: Nyathi, Michelle Y. Abstract: Minced meat is a nutritionally dense and highly perishable food, therefore there is need for preserving it. Most artificial preservatives currently used to prevent food spoilage have been reported to cause various health problems hence the need to use natural preservatives. Moringa oleifera and Brassica oleracea (broccoli) leaf extracts have proved their potential to be used as natural preservatives. The main objective of this research was to determine the antimicrobial efficacy of Moringa oleifera and broccoli leaf extracts as minced meat preservatives. Seven minced meat samples were prepared with different preservative concentrations. The first one had no preservative, the second one was preserved with 0.1% sodium sulphite, the third one was preserved with 1% Moringa oleifera leaf extract, the fourth one was preserved with 2% Moringa oleifera leaf extract, the fifth one was preserved with 1% broccoli leaf extract, the sixth one was preserved with 2% broccoli leaf extract and the seventh one was preserved with 1% Moringa oleifera and 1% broccoli leaf extracts. The minced meat samples were tested periodically (after 1, 12, 24, 48 and 72 hours) for microbial load (Total Bacterial Count, Coliforms, Salmonella, Escherichia coli and Staphylococcus aureus), colour stability and sensory analysis. Escherichia coli and Salmonella were not detected in all samples. The Total Bacteria, Staphylococcus aureus and Coliform counts for the samples varied from 4.3- 5.98 log CFU/gram, 1.32- 3.91 log CFU/gram and 3.4- 5.3 log CFU/gram respectively. The colour a*, L* and b*- values had ranges between 5-14, 53.2- 44.2 and 12- 15 respectively. The differences were compared using Graph pad prism 4 one way ANOVA for significant difference (α 0.05). It was concluded that there was no significant difference in the shelf life of the minced meat preserved with broccoli and Moringa oleifera leaf extracts to the one preserved with sodium sulphite.

2017-01-01T00:00:00Z Nyathi, Michelle Y.