ghanaopendata/ghanaian-research-english huggingface dataset:
Studies on levels of mercury, zinc and cadmium in soils and cassava in the vicinity of an alluvial goldmine at Dunkwa-On-Offin

Studies on Hg, Zn and Cd in soils and cassava crop were carried out in the vicinity of Dunkwa-On-Offin where there is alluvial mine. The samples were collected from farms, the vicinity of the gold house and the dredge sites within 20 km by the shortest distance from the centre of Dunkwa-On-Offin. Flame - Atomic-Absorption Spectrophotometric technique was used to determine the levels of Cd and Zn while the cold vapour Atomic Absorption Spectrophotometric technique was used to determine the Hg levels. The range of the concentration of the metals in surface soils (0-5 cm) was as follows; Hg, 32.9 μgkg-1 to 274 μgkg-1 Cd, under no detectable limits of the analytical method to 4.75 mgkg-1. Zn ranges from 18.5 mgkg-1 to 75.6 mgkg-1. The zinc showed a decreasing concentration with depth in soil up to 30 cm zone while the Hg and Cd showed irregular trends with depth. For cassava tissues, the flesh, the leaves and the peels (the peridem and the cortex), showed different levels of the metals. The metal concentrations in the flesh were for most samples less than those in the peels and leaves. The peridem (outer peel) mostly showed higher metal concentrations than the cortex (inner peel) The leaves had the highest levels of Hg and Zn indicating that the source was aerial The range of the metals in the cassava tissues is as follows Hg, 3.06 μgkg-1 to 35.17μgkg-1 Zn, 10.6 mgkg-1 to 123.30 mgkg-1 Cd, 0.45 mgkg-1 to 4.08 mgkg-1

Source: KNUST
Studies on some selected food-grade plant exudate gums in Ghana

Gums are incorporated into food products to improve their quality and enhance their shelf life. Gums are recommended for use in food products based on their qualities. In Ghana, gums utilized by the food industry are imported though enormous potential for their exploitation exists. Therefore this study was conducted on gums from three tree species in Ghana namely Albizia, Cashew and Khaya. The properties of these gums were compared with those of commercial gum arabic obtained from Ghana to determine their suitability as food additives. The qualities studied include pH, sweffing power, solubility, water binding capacity, viscosity, emulsifying properties, percent moisture, ash and insoluble ash content, insoluble matter, variation of temperature with viscosity and stability of pH with time, of the gum exudates. Khaya gum (viscosity, 514 mPas at 2 %) and Albizia gum (viscosity, 2224 mPas at 2 %) were more viscous than Cashew gum (viscosity, 486 mPas at 10 %) and can therefore be used for thickening and bodying better than the latter. Cashew gum was, however, viscous than Acacia gum (viscosity, 203 mPas at 10 %). Like Acacia gum, all the three gums showed increase in viscosity with concentration and also increase in viscosity with decreasing shear rate, indicating that they are non-Newtonian solutions. Apart from Khaya gum which was found to be temperature stable and therefore did not show reduction in viscosity with increasing temperature, the other two gums just like Acacia gum showed this property. Albizia gum had the highest swelling power, making its viscosity break down relatively faster than the others. The water binding capacities (WBC) of Albizia and Khaya gums were significantly different from that of Cashew and Acacia gums (at p< 0.05). However, the WBC of Cashew and Acacia gums were not significantly different. Therefore the former can be used to inhibit ice crystallization and prevent staling in baked foods. Cashew gum can be used in bakery toppings to prevent the absorption of excess moisture by icing. Khaya gum was less acid stable but the acid stabilities of Cashew and Albizia gums compare favourably with that of Acacia gum. They can therefore perform better in acidic foods than the former. The emulsion stability (ES) value of Acacia gum was not significantly different from that of Cashew gum (at p< 0.05), but was significantly different from Khaya and Albizia gums. Therefore Cashew gum can stabilize emulsions better than Albizia and Khaya gums. Each of the gums has been found to possess some good qualities that make it a potential substitute in certain food products. Toxicological studies on the gums should, however be carried out.

Source: KNUST
Studies on the assessment of income taxpayers’ utilization of personal tax reliefs: a case study of Greater Accra Region.

The achievement or disappointment of every government all over the world in carrying out several developmental projects depends mostly on the amount of income it is able to generate to finance its expenditure. In other not to evade tax government introduced incentives to reduce the tax burden of the taxpayer amongst them is the tax relief. This research gives an insight into the income tax payer‟s utilization of personal tax reliefs. The study is settled using the quantitative research approach through cross sectional survey of self-employed, public and private sector workers of the Greater Accra Region. The findings of the research revealed that the level of awareness of personal tax reliefs is high. However, its utilization is low due to various reasons including: the process for application of the reliefs is time consuming and bureaucratic in nature, and lack of adequate education on the benefits that can be derived from the reliefs. The study concludes that the level of awareness of personal tax reliefs is high but its utilization is low. In other to address the problems associated with the study GRA is recommended to deploy experience staff when it comes to service delivery to the taxpayers. In addition, the GRA is also recommended to migrate fully from the manual system to complete computerised system in other to reduce time spent at the office when applying for personal reliefs.

Source: KNUST
Studies on sweet potato viruses from the major sweet potato growing agro-ecologies of Ghana

Sweetpotato virus disease complex (SPVD) is the most destructive viral disease in Africa. It can cause yield loss up to 50%. In Ghana, not much work has been done on the identification and detection of sweetpotato viruses from the major sweetpotato growing agro-ecologies. A study was conducted to ascertain the incidence of sweetpotato viruses from the major sweetpotato producing areas and to ascertain the effects of sweetpotato virus diseases (SPVD) on the crop in Ghana. Sweetpotato viral disease samples were collected from all agro-ecologies in Ghana where the crop is grown and then preserved in the screenhouse for diagnostic purposes. Nitrocellulose membrane (NCM) enzyme-linked immunosorbent assay (ELISA), using specific virus antibodies and PCR techniques involving the use of specific and degenerate primers were used for the diagnostics. Virus diagnostics were done directly on virus-infected sweetpotato samples collected from the field and also on Ipomoea setosa indicator plants after they have been grafted with virus-infected sweetpotato collected from the various locations. In all, 127 samples were assayed. Effects of SPVD were assessed on three sweetpotato varieties, namely; ‘Dadanuei’, ‘Ligri’ and ‘Bohye,’ which are all varieties released by the CSIR-Crops Research Institute, Fumesua, Ghana. These were put under four levels of disease regimes; tissue culture cleaned and virus indexed planting materials, apparently healthy planting material collected from the field, virus infected planting material collected from field and artificially (using whiteflies) infected planting materials. There were four treatments and each treatment was repeated three times in a randomized complete block design (RCBD). Virus diagnostics, using NCM-ELISA, detected the following viruses; SPFMV (85.71%), SPCSV (16.67%), SPCaLV (6.35%), SPVG (4.76%), SPMSV (4.76%), SPCFV (1.57%) and CMV (3.97%). RT-PCR and PCR confirmed the detection of SPFMV and SPCSV as well as Begomoviruses in some of the samples. Several mixed infections were also detected in samples collected mostly from local varieties whilst the released varieties had mainly single virus infections. The study has also optimized serological detection (NCM-ELISA) and RT-PCR protocols for the effective diagnosis of sweetpotato virus isolates in Ghana. Across board, tissue culture cleaned virus-indexed planting materials of the three varieties produced the largest yield with a mean of 12.00 tons/ha, whilst artificially infected (whitefly inoculated) planting materials produced the least yield of 0.78 tons/ha. The study revealed planting tissue culture cleaned virus indexed planting materials can affect yield of the crop positively whilst it showed the usefulness in planting improved varieties, compared to the local varieties in term of virus infections.

Source: KNUST
Studies on the characteristics of alluvial gold ores in some parts of Ghana

The characteristics of placer gold ores obtained from along the Offin River (i.e. Upper, Middle and Lower Offin areas) and some of its tributaries (such as the Bonte, Oda and the Jimi streams) were investigated. The studies revealed that the gold particles in the samples studied with optical and electron microscope have varied shapes and surface properties that could affect the recovery of such particles. While some of the particles were spheroidal, others were rod-like, platy, as well as, had projections on the surfaces. It was also observed that the surfaces of some of the particles were tarnished with compounds of silicon, calcium, zinc, titanium, iron, and copper. Gold particle dispersity varied from sample to sample and with depth. In some cases, the greater than 125 μm gold particles were found in the first 2.0 metres whilst in others these occurred at depths closer to the bedrock. It was also observed that in most cases the number of finer gold particles (less than 125 μm) were more, although, in terms of mass were negligible. In samples with high clay content, desliming was only possible with large amounts of water and in some cases clay balls were formed which captured or occluded some of the gold particles.

Source: KNUST
Studies on the characteristics of cassava starch

Starch is the major component of cassava roots and an important source of calories for human food and animal feed. The physicochemical properties of starch from both fresh tubers and dried chips of four cassava (Manihot esczilenta Crantz) varieties; Gblemoduade, Abasafltaa, Isu-white and Afisiafi were studied to establish the effects that drying and varietal differences have on physicochemical properties and to select the varieties with suitable characteristics for pasta production. The parameters studied included amylose content, pH, granule size and shape, solubility, viscosity, water - binding capacity, swelling power and pasting characteristics. There were significant differences (P<0.05) in properties between starch from dried chips and those from fresh tubers for a given variety of cassava. With the exception of water-binding capacity (WBC) and solubility values which were higher for starch from dried chips, the values for other properties were lower than starch from fresh tubers. Gblemoduade (GB) which had the lowest yield of starch gave the highest values for most of the properties studied. The results indicate that drying of the chips and varietal differences have some profound effects on the starch quality and yield. The sensory analysis involving the overall acceptability of the cooked pasta revealed that Gblemoduade with high swelling power, water-binding capacity, amylose content, peak viscosity (from Bradender Visco-Amylograph) did not produce good pasta. However Abasafitaa which had most of its properties being lower produced the best cooked pasta from both starch and flour.

Source: KNUST
Studies on the Anti-Inflammatory Properties of the Aqueous Ethanol Extract of the Stem Bark of Bombax Costatum P.V

The stem bark of Bombax costatum (family: Bombacaceae) is used traditionally in Ghana for the treatment of many inflammatory diseases. The present study evaluated the effect of aqueous ethanol stem bark extract of Bombax costatum on carrageenan-induced paw oedema, cotton-pellet tissue granuloma formation and adjuvant-induced arthritis. The work also established its possible mechanisms of action using clonidine and haloperidol-induced catalepsy, PGE2-induced paw oedema; and determination of serum cytokines levels after acetic acid-induced colitis in rats. Carrageenan-induced foot oedema in chicks was used to assess the effect of the extract on acute inflammation. Extract of Bombax costatum (EBC) showed maximal inhibition of 21.22 ± 1.18 %, 18.39 ± 1.31 % (prophylactic study) at 50 and 100 mg kg-1 and 24.97 ± 1.89 % (curative study) at 100 mg kg-1 respectively. For cotton-pellet granuloma formation; EBC (10-100 mg kg-1) significantly reduced the total granuloma formation in both wet and dry cotton-pellets by 49.01 % and 54.53 % at 100 mg kg-1 respectively. In adjuvant-induced arthritis, EBC significantly inhibited maximal oedema to mean maximal inhibition of 139.49 ± 8.04 %, 136.96 ± 9.71 % and 132.14 ± 12.33 % at 10, 50 and 100 mg kg-1 respectively. Cataleptic responses induced in mice using clonidine was inhibited by EBC with maximal percentage inhibition of 17.50 ± 1.94 % and 12.75 ± 0.85 % at doses of 50 and 100 mg kg-1. EBC reduced the total oedema in PGE2-induced inflammation remarkably by 53.06 % at 100 mg kg-1. EBC reduced total serum levels of IL-6 and TNF-α significantly by 47.32 %, 70.57 % and 37.91 %, 50.32 % at 50 and 100 mg kg-1 respectively. Preliminary phytochemical analysis of aqueous ethanol stem bark extract of Bombax costatum indicated the presence of terpenoids, saponins, tannins, phytosterols, alkaloids, reducing sugars and flavonoids which could possibly be attributed to its anti-inflammatory effects on acute and chronic inflammation.

Source: KNUST
Studies on the Concentration and Diversity of Airspora in an Apiary at the University for Development Studies- Nyamkpala Campus, Northern Region, Ghana

Fungal species were sampled from the atmosphere around beehives at an apiary at various points from the beehives at various heights above the ground at these points for eight weeks by exposing Petri dishes containing fungal growth media for five minutes. Three nutrient media were used namely: PDA, MEA and SA. Samples were taken at different times of the day to determine diurnal variation in fungal concentration. Eleven different species of fungi were identified from the site of study. The most commonly occurring species was Aspergillus niger (115.31) whiles the least occurring fungi was Trichoderma sp (12.25). There was significant difference between the concentration of fungi around the beehives (0meter) and the concentration distance away (100 meters). The concentration of fungi was more around the beehives than at a distance (100meters) away. Aspergillus niger(58), Aspergillus versicolor(36.69), Curvularia sp.(24..63), Fusarium sp.(20.94), and Mucor(10.15) occurred more frequently at a height of 2m above ground than at 0.5m above ground whiles species such as Aspergillus ocraceous(10.43), Aspergillus tamarii(14.42), Neurospora sp.(31.37) , Penicillium sp.(22.31) , Rhizopus(11.69) and Trichoderma sp(6.15) were more abundant at 0.5m above ground than 2m above ground. With regards to diurnal variation, Aspergillus niger, Aspergillus tamari, Curvularia sp, Fusarium sp, Mucor, Rhizopus and Trichoderma sp. occured more frequently in the evening (5.00pm or 17.00h). Species such as Aspergillus versicolor, Aspergillus ocraceous , and Neurospora sp. were more common in the morning (7.00am or 7.00h) .There was relatively low abundance of the various species in the afternoon (12.00noon or 12.00h). It is however observable that there vi was no marked variation between the individual numbers of species for the three different times of which sampling were made. The highest fungal counts were made in the evening, followed by morning and then noon. With regards to influence of growth media on fungal concentration, the highest numbers of fungal counts were isolated from PDA, SA and MA respectively.

Source: KNUST
Studies on the factors that determines access to credit facilities for farmers: A case of Atwima Kwanwoma District.

Agricultural lending or financing involves giving out credit to small- scale farmers for the purpose of farming. However in view of the risky nature of the farming business, financial institutions are not willing to lend farmers. This study, factors determining access to credit facilities for farmers: a case of Atwima Kwanwoma district used a sample size of 120 respondents, made up of 100 farmers and 20 bank officials. The respondents were purposely selected for the study. The study used both descriptive and qualitative research approaches. Data was collected through questionnaires. The study revealed the following findings: the types of financing provided were overdraft; business loans; and group loans. The study identified the factors that determine access credit as collateral and farm size. They study also noted that increase in capital; expansion of farms; improvement in service; improvement in the standard of living contributed to the growth of the agriculture sector. Challenges of agricultural financing were identified as collateral security; repayment period; lack of records and statistics. Challenges financial institutions face in loaning to farmers were identified as inadequate information and risky nature of farming business; high transaction cost; lack of credit rating agency; lack of expertise and succession planning. The following recommendations were proposed; availability of information ; forming farming groups to lower transaction cost of financial institutions; credit rating agency; management expertise; and effective succession planning. It is believed that if these recommendations are put in place the challenges of agricultural financing could be addressed.

Source: KNUST
Studies on the Film Coating Potential of Anacardium Occidentale (Cashew Tree) Gum

This research work involved the study of Anacardium occidentale (cashew) gum as a material for pharmaceutical film coating. Both the crude and purified forms of the gum were evaluated for some physicochemical properties. The percentage yield for the purification was appreciable. The gum was found to be acidic and its viscosity significantly increased with increasing concentration and storage time. Both crude and purified gums had acceptable insoluble matter and moisture content. Polymeric films were prepared from homogenous solutions of the purified cashew gum only and mixtures of the cashew gum with either hydroxypropyl methylcellulose (HPMC) or carboxymethyl cellulose (CMC) using the solvent casting method in plastic petri dishes, using different plasticisers. The physical (weight and thickness) and mechanical (folding endurance, tensile strength, percentage elongation, Young’s modulus) properties of these films were determined. Paracetamol tablets were prepared and used as the model drug for the research work. The tablets were film coated with solutions of the cashew gum using different coating times. Quality tests including uniformity of weight, thickness, hardness, friability, disintegration time, assay and dissolution on both the uncoated and film coated tablets were conducted. The results obtained established that propylene glycol is not a suitable plasticiser for cashew gum and that blending cashew gum with hydroxypropyl methylcellulose or carboxymethyl cellulose produced non – uniform and films of poor clarity respectively. Cashew gum on its own produced transparent and smooth, but brittle films. Addition of plasticisers to the gum imparted flexibility to the films. Increasing cashew gum and plasticiser concentrations in the films increased the folding endurance and elongation of the films. Tensile strength was enhanced when gum amount was increased but a decrease in tensile property was observed when plasticiser amount was increased. Young’s modulus decreased when both cashew gum and plasticiser amounts were increased. Both uncoated and coated tablets passed all the quality tests. Application of the gum as a film coat to paracetamol tablets enhanced the mechanical strength of the tablets, in terms of friability and hardness. The rate of drug release was higher for the uncoated paracetamol tablets than for the film coated ones. The percentage drug release in phosphate buffer (pH-6.8) was higher than in 0.1M HCl dissolution medium. Film coating of core paracetamol tablets did not significantly impact on the immediate-release nature of the tablets. The mechanism of drug release from the tablets was found to be by diffusion. Cashew gum can therefore be used successfully as a film coating agent for immediate-release tablets.

Source: KNUST
Studies on the formulation and utilization of cassava flour

Cassava is one of the most important food crops produced in the tropics with an estimated global production in 1990 of 157 million tonnes of which 73 million tonnes were produced in Africa (Anon, 1990). It is estimated that 65% of total production is used for human consumption (Trim and Fish, 1993). About 40% of all calories consumed in Africsa come from cassava (IITA, 1990). This makes cassava an indispensable crop for the tropics. However cassava is highly perishable and must be processed into more stable products. Drying is the simplest method for processing cassava but the traditional product obtained is often of poor quality thus limiting its use. Studies were made on producing better quality dried cassava chips and utilizing them for some value added products. The effect of pretreatment and varietal difference on the quality of dried cassava chips was studied. Two improved cassava varieties Àbas qfitaa and Gblernoduade and one local variety Dabo were used. These varieties were subjected to the following pretreatments before drying (a) soaking overnight In water (b) washing in 1% sodium meta bisuiphite (c) parboiling for 5 minutes. Proximate analysis, pH, acidity and colour determination on the final dried products were carried out. Soaking improved the colour of final dried product. Dabo gave the whitest flour for all pretreatments. The pretreatment and variety combination that produced the best quality chips and flour was soaked Dabo. This flour was used to prepare bread, cookies and pasta. The quality of the bread was poor but very good cookies were made from 100% cassava flour. Good pasta was made from composite flour consisting of cassava, wheat and cowpea flours but the best pasta was made from cassava from which the starch had been partially expressed before drying.

Source: KNUST