School of Industrial Sciences and Technology

Permanent URI for this communityhttps://cris.hit.ac.zw/handle/123456789/4

Browse

Now showing 1 - 20 of 28

Aphrodisiac properties of some Zimbabwean medicinal plants formulations
(African Journal of Biotechnology, 2009-11-16) Gundidza, G,M; Mmbengwa, V.M; Magwa, M.L; Ramalivhana, N.J; Mukwevho, N.T; Ndaradzi, A; Samie, A
The aim of the present study was to determine the effects of formulations composed of Mondia whitei, Ekebergia capansis, aloe tincture (Aloe exelsa) and pumpkin seed (Cucurbita pepo) on sexual behaviour of inexperienced male rats. Male rats were treated orally with ethanol extracts of M. whitei and E. capensis, aloe tincture (from aloe juice) and pumpkin seed powder. The sexual behaviour of the rats treated with extracts was compared with those treated with 100 µg of testosterone as the positive control and those receiving normal rat feed as negative control. The receptivity of the females was rendered homogeneous with daily dose of estadiol benzoate. The sexual behaviour of the rats were observed over one ejaculatory phase for five consecutive days. The results showed a dose dependent increase in sexual arousability (decreased mounting latency), copulatory efficiency (decreased intercoupulatory interval) and improved sexual sensation (increased in neuromotor activity) for the rats treated with M. whitei and E. capensis, aloe and pumpkin seeds showing an increase in sexual performance in terms of intromissions and ejaculatory latency which also improved sexual sensation and coupulatory efficiency. The formulations of plants under investigation showed significant aphrodisiac properties.
The chemical composition and biological activities of essential oil from the fresh leaves of Schinus terebinthifolius from Zimbabwe
(Academic Journals, 2009-12-15) Gweru, N; Gundidza, M; Magwa, M.L; Mmbengwa, M.V; Samie, A
In the present study, the essential oil from the fresh leaves of Schinus terebinthifolius was extracted using the hydrodistillation method. The oil yield obtained was 0.65%. Gas chromatography and mass spectroscopy (GC-MS) analysis of the essential oil showed that the major constituents of the essential oil were sabinene, -pinene, -phellandrene, -pinene, terpinene-4-ol, trans--ocimene and myrcene. Using the hole-plate diffusion testing method, the essential oil exhibited potent antibacterial activity against Yersinia enterocolitica, Pseudomonas aeruginosa, Escherichia coli, Acinetobacter calcoaceticus, Bacillus subtilis, Klebsielia pneumoniae and Bacillus subtilis with at least 58% inhibition compared to the positive control. The mycelium growth inhibition method was used for anti-fungal testing. The essential oil exhibited activity against Aspergillus flavus with 58% inhibition, Candida albicans with 49.8% inhibition and Aspergillus niger with 48.7% inhibition. The -carotene, acetone and linoleic acid method was used to assess the antioxidant activity of the essential oil. The essential oil showed anti-oxidant activity of 13.1 mm mean zone of colour retention representing 72.7% activity compared to the positive control (ascorbic acid). This is the first study on S. terebinthifolius collected from sub-saharan Africa indicating the presence of trans--ocimene in the essential oil and its strong antibacterial activity against Y. enterocolitica and P. aeruginosa as well as moderate antifungal activities of the plant.
Chemical composition of volatile constituents from the leaves of Aloe ferox
(African Journal of Biotechnology, 2006-09-10) Magwa, M.L; Gundidza, M; Coopoosamy, R.M; Mayekiso, B
Volatile compounds oils play a significant role in perfumery, cosmetic, medicinal and pharmaceutical industries. In our protracted research for new useful essential oils, a volatile oil from Aloe ferox was obtained by prolonged hydrodistillation. This volatile oil was subjected to GC/MS analysis to identify the major constituents of the oil. The major constituents identified were as follows: 3, 6 octatriene (23.86%), 3-cyclohexane-1-hetanol (7.31%), Bornylene (5.24%), 1, 3-cyclopentadiene (4.07) and 5-methyl3-heptanol (3.92%). A significant number of other volatiles were also identified but in minor concentrations.
A comparative analysis of different pitching rates on castle lager beer flavour stability:
(International Journal of Nutrition and Food Sciences, 2014-10-20) Muredzi, Perkins; Chiridza, Lyneete Tendai; Moyo, Dinga.N; Winini, Clive
Beer stability is a critical quality parameter and there is vast amount of research that has been done in attempt to understand and optimise it. The research study was incited by the result of low lag time (potential to resist staling) and high T150 (degree of staling) in one of the main stream brands at the beer processing firm, which caused the beer to stale much faster than normal. The research focused on the flavour stability aspect of beer stability and different methods of analysis were employed to investigate the effect of different pitching rates on products of yeast metabolism in-turn flavour stability. Results revealed that beer fermented with a low pitching rate had a high amount of sulphur dioxide which meant the Lag Time was also high due to sulphur dioxide exerting anti-oxidant properties which prevented oxidation of beer for longer periods than beer fermented with a high pitching rate. The results also revealed that there is no significant difference in these beers regards sensory analysis following analysis using the t-test
Comparative Study of Degradation Kinetics of Ascorbic Acid (Vitamin C) in Tray Drying, Solar Drying and open Sun Drying of Pineapple Slices
(Austin Journal of Nutrition & Metabolism, 2015-06-01) Gwala, W; Padmavati, R
A comparison of degradation kinetics of ascorbic acid was done on tray, solar and open sun drying of pineapples. Thin slices of 10mm±3 thickness were equally weighed and divided into three samples of 300g each. One 300g sample was placed in a tray dryer and dried at a temperature of 60oC, the next 300g sample was placed in the solar dryer and another 300g sample was placed on a tile for open sun drying and dried under fluctuating temperatures. Samples were taken at half hour intervals and analysed for vitamin C content over the drying period using the 2,6 dinitrophenolindophenol dye titration method. The residual vitamin C content in tray drying was least at 11.25 mg/100g of sample. This was followed by sun drying with a residual vitamin C content of 19.5mg/100g of sample. Solar dried sample showed the highest vitamin C retention with 29.25mg/100g of sample weight. The degradation kinetics were analysed using the first order fractional Model and the Weibull Model. The correlation coefficient (R2) was calculated for goodness of fit. The Weibull model had the best fit. However deviation from first order degradation kinetics of vitamin C was noted.
A concise review of yam (Dioscorea spp.) starch: extraction, chemical composition, physicochemical properties and its potential food applications
(Taylor & Francis, 2024-12-30) Mawoneke, Kurai Gareth; Kwiri, Raphael; Ndemera, Melody
Substantial studies have been conducted on the starches derived from various yam species. These studies have examined numerous extraction methods, including acid, alkali, ammonia, water and enzymatic techniques, each yielding between 10–20% starch. The physicochemical properties of yam starches have been extensively characterized, evaluating factors, such as granule size, amylose content (ranging from 0 to 40%), gelatinization behavior and rheological profiles. Notably, the yam species D. esculenta and D. dumoterum exhibit lower amylose levels, while D. trifida can present as a waxy starch with less than 2% amylose. Minimal variation has been observed in the composition, patterning and characteristics across D. cayenensis and D. rotundata starches. Yam tubers are composed of 60–80% starch by dry matter, playing a fundamental role in the quality of yam-based foods. Yam starches have demonstrated potential as thickeners, fat replacers and edible film formers due to their physicochemical attributes, particularly their gelling properties which enhance texture and functionality. However, the industrial utilization of yam starches remains limited due to a lack of systematic data and standardized isolation methods. Further research is needed to optimize extraction protocols and expand the food applications of this versatile starch.
Correlates of blood pressure in an urban Zimbabwean population and comparison to other populations of African origin
(Journal of Human Hypertension, 2000-02-06) Mufunda, J; Scott, LJ; Chifamba, J; Matenga, J; Sparks, B; Cooper, R; Sparks6, H
We have evaluated the relationship between systolic blood pressure (SBP) and age, body mass index (BMI), waist circumference, sodium to potassium ratio (Na/K), and tobacco use in an urban African population. We conducted a random, population-based, cross-sectional survey of people 25 years and older in Marondera, Zimbabwe, with over-sampling in older age groups (n = 775), using a method comparable to that used in International Collaborative Study on Hypertension in Blacks (ICSHIB). The age-adjusted prevalences of hypertension in Marondera (SBP >140/DBP >90/antihypertensive medication) were 30% for women and 21% for men. The average BMI was 26.3 kg/m2 for women and 21.4 kg/m2 for men. The prevalence of hypertension had a steep association with age and in women ranged from 15% (25–34 years) to 63% (55 years and over) and in men from 9% to 47%. No tobacco use in women and greater Keywords: hypertension; obesity; Africa; black; Zimbabwe Introduction Many recent studies have reported high levels of hypertension in urban southern African populations.1–7 The prevalence of hypertension in an urban Zulu population in South Africa was 25% using World Health Organisation (WHO) criteria systolic blood pressure (SBP) >160 and/or diastolic blood pressure (DBP) >95 mm Hg for people between 30 and 65 years of age with slight increases and decreases in the criterion for younger and older people respectively.1 In an urban black population in Johannesburg, South Africa, the mean SBP in men and women aged 40–49 was 140 and 147 mm Hg, respectively, and was still higher in older age groups.2 Among women of child bearing age in a mining town in Zimbabwe, the prevalence of hypertension (SBP >160 or DBP >95 mm Hg or use of hypertensive medications) was 15%3 and the average SBP in urban Zimbabwean women, aged 40 and Correspondence: Dr Jacob Mufunda, Department of Physiology, University of Zimbabwe, P.O. Box MP167 Harare, Zimbabwe Received 30 July 1998; revised 21 April 1999; accepted 21 May 1999 Na/K ratio in spot urines in men were significantly associated with an increased SBP. In both men and women the levels of hypertension and SBP were strongly positively associated with BMI, although the relationship appeared to plateau in women with a BMI greater than >25 kg/m2 . At a given BMI, men and women had similar SBPs and prevalences of hypertension. There is a very high prevalence of hypertension among urban Zimbabweans, particularly among women. Under the assumption the studies are comparable, the prevalence of hypertension in Zimbabwean women (41%) and men (26%) after age adjustment to the ICSHIB populations, appeared higher than almost all of the ICSHIB populations, including those with higher average body mass indexes.
Development and evaluation of a plantain-peanut sandwich for the Nigerian market
(. International Journal of Nutrition and Food Sciences, 2014-06-19) Malomo, Olu; Uche, E; Adekoyeni, O. O; Alamu, E. A
Protein-energy malnutrition is a common nutritional disorder in developing countries and constitutes a major public health problem in young children and elderly people. This project is aimed at evaluating the acceptability of plantainpeanut sandwich and roasted at different temperatures. A plantain-peanut sandwich consists of minced protein stuffed into a carbohydrate source made into a roll as a food product. The plantain was roasted at two different temperatures then later enriched with 5%, 10% and 15% peanut butter. The crude protein and crude fibre contents of the plantain samples roasted at 200oC and 240oC showed no significant difference (P˃0.05) while the ash, fat and carbohydrate contents showed that there was a significant difference (P˂0.05). Results of the proximate composition showed that there was significant difference (P˂0.05) at the two different roasting temperatures of 200oC and 240oC when enriched at 5%, 10% and 15% levels with peanut butter. This pattern of significant increase was also observed with the amino acid profiles at the two different roasting temperature levels.
Effects of soya bean meal feed properties on extrusion failures and implementing a solution.
(International Journal of Nutrition and Food Sciences, 2013-03-10) Muredzi, Perkins; Nyahada, Moses; Mashswa, B.W
This research was a contribution on the optimization of extrusion process by determining the effects of feed properties on extrusion failures and implementing a solution. The objectives of the research were to increase the set soy meal to chunk conversion standard from 65% to 80%; to determine the effects of feed properties on extrusion failures; to determine the best conditions of the feed properties that promote an effective extrusion cooking process; and to determine a solution of optimizing these feed properties for successful extrusion. The research was company based and it followed the failures of extrusion experienced at Monmouth Path Investment (Pvt) Ltd in Waterfall, Harare. This research was limited to feed properties such as fat content, moisture content and particle size as the factors that cause extrusion failures. The determination of moisture content was done by using a moisture analyzer, fat content was determined through the Soxhlet method and the particle size of the feed was determined through sieve analysis. The results revealed that extrusion process was most successful when the soy meals fat content was greater than 6.0%, with a moisture content less than 6.0% and particle size range of 0.95-1.0mm. The process of optimization of extrusion process was solved by designing an extrusion calculator and blending ratio factors. The objective of determining the effects of feed properties on extrusion failures was achieved as well as that of implementing a solution. The objective of increasing Monmouth Path’s standard soy meal/chunk conversion was partially achieved since the implemented solution is not yet measurable.
Food is Medicine -
(LAP Lambert Academic Publishing., 2013-07-30) Muredzi, Perkins
A combination of the words "nutrition" and "pharmaceutical," the term nutraceutical encompasses foods or food products that claim to prevent chronic diseases, improve health, delay the aging process, and/or increase life expectancy. Products in this category range from isolated nutrients, dietary supplements and specific diets to genetically engineered foods, herbal products, and processed foods such as cereals and beverages.The area of Nutraceuticals is relevantly new and hence this publication serves to be most vital for scholars studying pharmaceutical sciences and related disciplines and as a reference for college freshman intending to have more understanding of this emerging area. This book by Dr. Muredzi sets the tone for future editions and serves to give an enlightened introduction to this emerging discipline
Food Security and Intellectual Property Rights –
(LAP Lambert Academic Publishing, 2013-01-01) Muredzi, Perkins; Sackey, Emmanuel
This book gives an understanding of the relationship between IPRs and Food Security, the current status of food security in Sub Saharan Africa and discusses the issues and concerns regarding IPRs and Food Security. It also considers the question of sui generis protection from the perspective of food security. It examines the extent to which existing IPRs can fulfill the twin goal of promoting technological development and food security. It also examines further options that are open to Sub-Saharan Africa countries under the TRIPS Agreement and beyond the TRIPS Agreement, taking into account other treaties such as the International Treaty on Plant Genetic Resources for Food and Agriculture (International Treaty on PGRFA).
From Roots to Riches:
(Biotechnology Trust of Zimbabwe, 2004-01-01) Dhliwayo-Chuinzi, Patient D.
Grewia bicolor seed oil: Putative pharmaceutical, cosmetic and industrial uses
(South African Journal of Botany, 2015-06-12) Nyakudya, Trevor,T; Magwa, Michael,L; Chivandi, Elton; Nosenga, Noseiphi; Erlwanger, Kennedy L; Gundidza, Mazuru; Gundidza, Ernegy; Muredzi, Perkins
The physicochemical characterisation, seed oil content and fatty acid profile of oil extracts from Grewia bicolor seeds collected in Zimbabwe were performed using standard extraction and chromatographic techniques. The main objective was to determine the potential domestic and industrial usefulness of the G. bicolor seeds. The G. bicolor seeds yielded 4.80% of brownish-orange oil that had an acceptable odour. The seed oil consisted of saturated (20.20%), monounsaturated (25.10%) and polyunsaturated (54.41%) fatty acids. Palmitic acid (11.46%), stearic acid (5.77%), oleic acid (19.33%) and linoleic acid (54.41%) were the main fatty acids in G. bicolor seed oil. The oil had a high acid value (0.53 mg KOH/g), iodine value (39.21 g I2/100 g oil) and saponification value (130.43 mg KOH/g) compared to published data on other nutritionally and ethnomedicinally important plant seed oils. We conclude that the G. bicolor seeds are low oil yielding, whose oil could be used as a potential source of palmitic, stearic, oleic and linoleic acids and may potentially be utilized as an industrial ingredient in the manufacture of soaps, pharmaceutical products, and cosmetics. Further studies are required to explore the possibility of using this seed oil in industry.
Image Interpretation and radiographer commenting 1
(HIT, 2025-11-17) HIT
Inhibitory effects of herbal medicines with claimed anticancer indications on cytochrome P450—An evaluation of drug-herb interactions risk
(Elsevier, 2023-08-03) Mudyiwa, Misheck; Sharma, Manju; Ray, Samarendra Kumar; Masimirembwa, Collen; Thelingwani, Roslyn Stella
Herbs have the potential to interact with conventional medicines or each other upon concurrent administration. This can be at the level of absorption, distribution, metabolism and excretion (ADME). With an estimation that 80% of the population in poor regions of the world utilise herbal medicines for primary healthcare, there is a likelihood that some people will take both herbal and conventional medicines. This could present a risk for herb-drug interactions (HDI) at the various levels of the ADME process. Most common HDI have been observed at metabolism level involving inhibition or induction of the major drug metabolising liver enzymes called cytochrome P450s. In this study, we investigated the inhibitory effects of Parinari curatellifolia (MC), Fluggea virosa (ST), Garcinia livingstonei (MT), Pterocarpus angolensis (M), Tapinanthus quequensis (MF) and Cussonia arborea (GM) on recombinant CYP1A2, CYP2D6, CYP2C9 and CYP2C19. Plate based fluorescent assays were used to follow enzyme activity. Inhibition was determined at 5 mg/ml and 100 mg/ ml of herbal extract, with IC50 determined for herbs that showed potent inhibition. A total of 10 out of 13 extracts showed significant inhibitory effects. Pterocarpus angolensis(bark), Fluggea virossa (leaf), Cussonia arborea(bark), Parinari curatellifollia (root) had very potent effects on CYP1A2 as indicated by an IC50 of <9.9 μg/ml. Based on the worst-case-scenario of complete absorption and exposure, these herbs are predicted to result in HDI if co-administered with medicines which depend on the affected CYPs for metabolism and elimination. Significance of the main findings: There is a potential threat of drug toxicities due to drug-herb interactions for patients undergoing chemotherapy or taking other medications where comorbidities exist during chemotherapy. Drugs that are substrates of CYP1A2 should be administered with caution for patients who are taking the herbs which have been studied in this research as risk for drug toxicities may be high. The findings act as a guide to medical doctors and patients in evaluating potential for herb-drug interactions during prescribing medications which are substrates for the studied CYPs.
Investigation of shelf-life extension of sorghum beer (Chibuku) by removing the second conversion of malt
(Elsevier, 2008-12-04) Kutyauripo, Josphat; Parawira, Wilson; Tinofa, Sharai; Kudita, Ivy; Ndengu, Clement
The effect of removing the second step of malt conversion in the brewing of Chibuku beer was investigated with the intention of extending the shelf-life of the product. Chibuku was brewed in the laboratory scale fermenters using Delta Beverages' standard brewing procedure. A variation was made where the second malt conversion was not conducted on one brew. The effect of increasing pasteurisation time was also investigated. The extension of shelf-life was determined by following the physicochemical and the sensory profile of the products for a period of ten days under sub-tropical ambient conditions. Ethanol productions were similar between the control and test beers (without second conversion malt). A product with overall acceptability of 70% was made from the brew without the second malt conversion and with 15 min pasteurisation at 80 °C. The product was, however, low in bite and head retention, but had less bacterial load, decreased acid production, and improved keeping quality by at least two days. However, due to contamination of the pitching yeast with lactic acid bacteria (LAB), total acids rapidly increased after 168 h and caused unacceptable sourness. Increasing pasteurisation time to 20 min reduced bacterial load of the wort to figures as low as 2 × 103 cfu/ml. General hygiene levels of the brewery were acceptable and no coliforms were detected in the product or contact surfaces along the production line. Bacterial contamination of the product mainly comes from the raw materials with pasteurisation greatly reducing this load. If improved, the procedure has the potential of extending the shelf-life of the beer to beyond 168 h
An investigation on the causes of Escherichia coli and coliform contamination of cheddar cheese and how to reduce the problem
(International Journal of Nutrition and Food Sciences, 2014-09-20) Kwenda, Amanda; Nyahada, Moses; Musengi, Amos; Mudyiwa, Misheck; Muredzi, Perkins
The aim of this study was to investigate the causes of E. coli contamination of Cheddar cheese through the application of Hazard Analysis Critical Control Points (HACCP) principles. Cheese samples were analyzed for E. coli and coliforms after production, during the validation stage, as well as at the verification stage. Average E. coli and coliform counts were analyzed statistically using the t-test. Results showed that after the implementation of the corrective measures there was a decrease in E. coli and coliform counts at the 5% level of significance. Results presented in this study also show that manufacturing Cheddar cheese whole observing high standards of hygiene improves the reduces E. coli and coliform contamination of the product, even though the problem is not completely eliminated.
ISO 14040 Life Cycle Assessment (LAS) as a tool for effective environmentally friendly waste management in the Food Industry
(National Renewable Energy Labaratory., 2009-01-02) Muredzi, Perkins
Life cycle assessment (LCA) is an analytical tool for the systematic evaluation of the environmental aspects of a product or service system through all stages of its life cycle. The food production industry requires large inputs of resources and causes several negative environmental effects. The food production systems are oriented and optimized to satisfy economic demands and the nutritional needs of a rapidly growing world population. Environmental issues, however, have not been given much attention. This review article discusses Life Cycle Assessment (LAS) as a tool for effective environmentally friendly waste management in the Food Industry and gives case studies and recommendations for the industry.
Isolation of citric acid producing Aspergillus niger strains
(LAP LAMBERT Academic Publishing, 2013-01-05) Muredzi, Perkins; Nyati, Hilda; Mudyiwa, Misheck
Microbiological quality of Gonimbrasia belina processed under different traditional practices in Gwanda, Zimbabwe
(International Journal of Current Microbiolgy Applied Sciences, 2014-01-02) Mujuru, Felix; Winini, Clive; Kwiri, Raphael; Nyambi, Clarice; Moyo, Dinga.N
TheaimofthisstudywastoinvestigatethemicrobiologicalqualityofMopaniWorms(MW)(Gonimbrasiabelina)processedunderdifferenttraditionalpracticesin Gwanda,Zimbabwe.FreshlyharvestedMopaneworms(MW)weredeguttedusingbarehandsorglovedhands.Thedeguttedwormsweresub-dividedinto4equal portions and subjected to different traditional drying methods namely, boiling insaltedwater(5%w/wsalt)for30minutesandsolardrying,openpanroasting,drumroastingandhot-ashdryingtoapproximately15%moisturecontent.Thereafter,driedMWsweremicrobiologicallyanalysedagainstindicatormicro-organisms(totalbacteriacounts,coliformsandEscherichiacoli)andpathogens(Salmonella spp.andStaphylococcusaureus)aswellasspoilageorganisms(yeastandmolds).Microbiologicaltestsconductedshowedthat,totalbacteriacounts(TBC)wererelativelylowwithvaluesrangingfrom10-2500CFUg-1. Significantly,deguttingMWsusingbarehandsfollowedbydrumroastingandboilinginsaltwatercoupledwithopenpanroasting,hadtheleastTBC(10CFUg-1and30CFUg-1)respectively.ColiformsandE.coliwerealsodetectedinMWswithvaluesrangingfrom0-43CFUg-1and0-30CFUg-1respectively(barehandsdegutted)whilstinglovesdeguttedMWscoliformscountswere0-45CFUg-1andE.colicountswere0-35CFUg-1.Furthermore,someMWsespeciallyashindriedsamplesthatcontainedvaryinglevelsandtypesofyeastsandmoldsthatincludedFusariumandPenicillium.NoSalmonellaspecieweredetectedinallsampletested.Thestudyshowedthat,MWprocessingmethodandsubsequenthandlingareimportantparametersindeterminingthetypeandlevelsoftheircontamination.Assuch,itisimperativeforharvestersandprocessorstoobservegoodharvestingandmanufacturingpracticesandfollowprotocolsthatdonotresultinre-contamination of produce as this might present a danger to the public consumers.