https://cris.library.msu.ac.zw//handle/11408/293 2026-04-08T09:44:40Z https://cris.library.msu.ac.zw//handle/11408/3560 Title: Suitability of yellow maize as an alternative to white maize as an adjunct in lager beer brewing Authors: Mawunganidze, Thelma T. Abstract: Yellow maize is used as a raw material in many food industries but its use as an adjunct in beer brewing has not received much attention. This study was carried out at Delta Beverages Southerton Plant, Harare, to determine the suitability of yellow maize as an adjunct in larger beer brewing in terms of proximate analysis of its milled grits and wort analysis. The proximate composition of the yellow maize milled grits was determined through analysis of moisture content, gelatinization temperature, fat/oil content, protein content, limit of extract and fermentability-alcohol content. The wort characterization of the yellow maize milled grits was done through analysis of wort gravity, starch presence and colour of cooked maize grits. Wort gravity (15.720 Plato) and colour of cooked maize grits of yellow maize was high compared to wort gravity (15.650 Plato) and colour of cooked maize grits of white maize. Yellow maize grits had a higher starch, content than white maize making it a better alternative since wort of a higher sugar content produces beer with a higher alcohol percentage. Protein content and moisture content of yellow maize (9% and 12%, respectively) were similar to those of white maize (8.46%, and 12.27%, respectively) and they were within acceptable ranges for lager beer manufacturing. Undesirable properties of yellow maize grits including high fat content, colour and gelatinization temperatures were recorded but they are insignificant since they can be managed during the brewing process. From the wort and proximate analysis done, yellow maize can substitute for white maize in lager beer brewing. 2015-01-01T00:00:00Z Mawunganidze, Thelma T. https://cris.library.msu.ac.zw//handle/11408/3004 Title: A comparative study of the effectiveness of alkaline soaking, bleach and boiling for pasteurization of substrate in the cultivation of white oyster mushroom (pleurotus ostreatus) Authors: Chipendo, Tawanda Michael Abstract: A study was carried out on substrate pasteurisation for P. ostreatus cultivation. The major aim of this work was to compare the effectiveness of wood ash, hydrated lime, bleach and boiling for pasteurisation of the substrate for cultivation of white oyster mushroom, Pleurotus ostreatus, on maize straw. To achieve this objective, weed occurrence, the number of days to completely colonise the straw (NDCC), the number of days to initiate primordial sprouting (NDIPS), the number of primordial colonies (NPC), the yield of the first fruiting flush (YFF) and the duration of the first fruiting flush (DFF) were measured. Analysis of Variance for RBD was done to compare NDCC and YFF. NDIPS, NPC and DFF were compared using the nonparametric Friedman’s test. There was low infestation of straw with Trichordema as well as yellow mould (Aspergillus spp.) in three bags. The NDCC was significantly different across treatments (ANOVA, p= 0.000) and boiling recorded the fastest rate of mycelial colonisation of straw taking 16.67 days. There was no significant treatment effect on DTIPS (χ2(3) = 4.188, p= 0.242) with the mean NDIPS ranging from 4.00, on boiled straw, to 4.67, on both bleach and wood ash. NPC also showed no significant treatment effect (χ2(3) = 1.575, p= 0.665) with treatment means ranging from 1.33, on bleach-treated straw, to 1.83 on boiled straw. YFF showed significant differences (ANOVA, p= 0.000) for at least two treatments. The lowest yield was obtained on straw pasteurised with bleach (BE = 22.30%) while ash-pasteurised straw gave the highest yield (BE= 37.34%). DFF showed no significant treatment effect (χ2(3) = 4.860, p= 0.182). The mean DFF ranged from 16.67, on bleach-treated straw, to 18.00, on boiled straw. Pasteurisation of the mushroom substrate using sifted wood ash proved best for achieving high yield. Pasteurising using wood ash however requires more time for spawn run. Mushroom farming trainers can be encouraged to incorporate some of the chemical pasteurisation methods like use of bleach, hydrated lime and wood ash into their training programs especially in in urban areas where wood is not readily available. Instead of disposing of wood ash, farmers may consider using it for the purposes of growing mushroom and reduce the amount of fuel demand for the enterprise. 2016-01-01T00:00:00Z Chipendo, Tawanda Michael https://cris.library.msu.ac.zw//handle/11408/2806 Title: Prevalence and antibiotic susceptibility patterns of Pseudomonas aeruginosa in clinical isolates: a case study of Bulawayo metropolitan province Authors: Chazanga, Leona Abstract: Pseudomonas aeruginosa is gram negative bacterium which causes nosocomial infections in patients and is highly resistant to most antibiotics as it possess numerous mechanisms of resistance. These mechanisms possessed by P. aeruginosa make it difficult to treat in infections thus being of medical concern. A study was carried out to determine the prevalence and antibiotic susceptibility patterns of P. aeruginosa isolated from wound pus and urine samples. A total of 1200 primary cultured samples from patients with urinary tract and wound infections were screened for P. aeruginosa at two medical laboratories (Diagnostics Laboratory Services and Southern Pathology Laboratory) in Bulawayo from July 2015 to January 2016. P. aeruginosa was identified using standard biochemical tests according to Clinical Laboratory Standards Institute (CLSI) guidelines and its antibiotic susceptibility patterns to eight different antibiotics (Imipenem, Piperacillin, Piperacillin/Tazobactam, Ciprofloxacin, Norfloxacin, Gentamicin, Ceftriaxone, and Tetracycline) were determined using antibiotic zone diameters. A total of 78 samples tested positive for P. aeruginosa giving an overall prevalence of 6.5%. The prevalence of P. aeruginosa was higher in male patients (61.54%) than in female patients (38.46%). The eight antibiotics tested had significantly different efficacies against the P. aeruginosa isolates obtained from pus swab samples Chisquare P=0.000). Imipenem was the most effective drug on the P. aeruginosa isolated rom pus swabs (88.1%). Norfloxacin, Tetracycline, Gentamicin and Ceftriaxone were the least effective drugs on P. aeruginosa and had the same efficacy against the P. aeruginosa isolates obtained from pus swab samples (P=0.591). Therefore, the latter four antibiotics may not be considered as treatment options for P. aeruginosa mediated wound infections. However, Piperacillin, Piperacillin/Tazobactam and Ciprofloxacin can be used as alternative treatment options for P. aeruginosa mediated wound infections. In terms of their efficacy against P. aeruginosa isolated from urine samples, the eight different antibiotics could be placed in two major categories (P=0.000). Imipenem, Piperacillin, Ciprofloxacin and Piperacillin/Tazobactum were the antibiotics of choice and had equally the same efficacy against P. aeruginosa isolated from urine samples (P=0.120). These four antibiotics were significantly the most efficant antibiotics which can be used interchangeably in treating P. aeruginosa mediated urinary tract infections. The other four antibiotics (Norfloxacin, Gentamicin, Ceftriaxone and Tetracycline) were equally inferior to the latter antibiotics in terms of efficacy (Chi-square P=0.000). This study showed that P. aeruginosa was sensitive to Ciprofloxacin and resistant to Norfloxacin regardless of both belonging to the Quinolone class of drugs. Overall, all the isolates, irrespective of sample type were highly sensitive to β-lactams (Imipenem, Piperacillin and Piperacillin/Tazobactum). This study further showed that there were 32 antibiotypes for P. aeruginosa isolated from pus swab isolates and 29 antibiotypes for P. aeruginosa isolated from urine samples. This showed that different P. aeruginosa isolates respond differently to the same antibiotic. The most common antibiotype for pus swab P. aeruginosa isolates was NorRTetRGentR CeftRCipR with a frequency of 11.90%. The most common antibiotype for urine P. aeruginosa isolates was NorRTetRCeftRCipR with a frequency of 8.34%. The rest of the antibiotypes for urine and us swab isolates were unique and revealed high multi-drug resistance. The recommended effective drugs for treating P. aeruginosa mediated urinary tract infections in this study are Imipenem, Piperacillin/Tazobactam, Piperacillin and Ciprofloxacin respectively. Imipenem, Piperacillin, Piperacillin/Tazobactam and Ciprofloxacin respectively are recommended as treatment choices for wound infections. Imipenem is recommended as the antibiotic of choice in treating P. aeruginosa mediated wound and urinary tract infections. 2016-01-01T00:00:00Z Chazanga, Leona https://cris.library.msu.ac.zw//handle/11408/2565 Title: An investigation into the effects of storage periods on germination vigour and malt quality in malting barley (hordeum vulgare), variety “hope” :a case study at Delta beverages, Kwekwe maltings Authors: Sithole, Ashley Simiso Abstract: Malts with high extract values, high enzymatic activities and good modification are fundamental to increase the brewing yield and efficiency. 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 assess the changes in seed germination vigour trends and the general storage stability of a Zimbabwean two-row malting barley variety “Hope” as the post-harvest storage time increased. Five samples of this commercially grown variety were obtained and stored under room temperature conditions. The samples had their germination capacity and energy determined using SAB Miller standards for malting barley analysis (controlled germination in an incubator at 180C – 210C for 72 hours). In addition other quality parameters (moisture content, water sensitivity, diastatic power, total extracts, free amino nitrogen and friability) necessary to assess the storage stability were analyzed using the same analytical standards as for germination tests for each sample. Results showed that “Hope” is better malted after a storage time of 2 years meaning that, the variety’s germination vigour improves with time. However, at storage periods of more than 2 years, undesirable quality trends were observed and this could be because most of the grains are presumed dead. Malting of grains just after harvest also produced undesirable results probably because the grains were still dormant as dormancy breaks after 3 months of harvest. Dormancy is a common characteristic of seeds that retards rapid and uniform germination and thus it has the potential to affect malt quality adversely. Parameters measured before malting are moisture content, germination capacity, germination energy and water sensitivity. The results showed an increase with decrease into storage years, that is from 2011-2015. An exception was observed in water sensitivity as the results showed a decrease as years into storage decreased. Results after malting showed general increases as years into storage decreased, that is for, DP, FAN and extracts. However, for filtration speed, friability, PUGS, WUGS and TSN a decrease was observed with decreases in storage years. From the results obtained, it can also be concluded that “Hope” is more stable in storage of not more than two years. Thus after considering germination performance and general malt quality after storage it was concluded that “Hope” is a good malting barley variety. Since all malt quality parameters measured in this study significantly influence brewery efficiency, these findings have a significant commercial impact. 2016-06-01T00:00:00Z Sithole, Ashley Simiso