African Journals Online

JOURNAL OF THE GHANA SCIENCE ASSOCIATION

VOLUME 2 No. 3 – 2000

Biotechnology and the food industry: some potentials for Ghana

George Y. P. Klu

Biotechnology and Nuclear Agriculture Research Institute

(Ghana Atomic Energy Commission), P.O. Box LG 80, Legon.

ABSTRACT

Biotechnology has played a major role in the traditional food and agriculture industry particularly in the areas of food fermentation, biological control of pests, and conventional animal vaccine production. The need to augment food production to meet the increasing population in Ghana requires that modern techniques be adopted. Modern biotechnology based on advances in biology, genetics, chemistry and engineering is being used for major developments in food and agriculture in many countries. Biotechnology offers a great potential for meeting the demands of the food and agriculture industry in Ghana in the next millennium. The potential areas of application including crop production, animal production, health and food processing are herein discussed.

Upstream processing of agricultural produce: prospects and challenges for Ghana's economic development

P.K. Awua

Cocoa Processing Company Ltd., Tema.

ABSTRACT

The world economy is dynamic and buoyant and with its technological developments one cannot sit idly by and be complacent, otherwise one would be overtaken by events. Developed countries have reached electronic, computer and satellite age. Should the developing countries like Ghana be satisfied with her present stage of agricultural development which supplies raw materials to the developed nations? Ghana is basically an agricultural country with fertile savanna and forest land which can be used to cultivate all kinds of food and commercial crops. Its natural resources should therefore be harnessed to its best advantage. Ghana Export Promotion Council is doing all it can for the export of the non-traditional products either in processed or raw/fresh forms which contributed about 8% of the export proceeds in 1997. Of these export proceeds of non-traditional products, processed and semi-processed products contributed 81.12%. However, in terms of the tonnage of the processed products the quantity was quite small. In 1997 the Agricultural Sector contributed 40.1% to the GDP. This contribution is not enough to justify its rich savanna and forest. This situation can be improved by reviewing the land tenure system, the small-scale farming practices, the low yields of the produce, lack of sufficient material and financial support, poor marketing practices, post harvest losses, as well as undeveloped infrastructure like roads, water, electricity, dams, irrigation, etc. The bulk of the food surpluses which would be produced when the agricultural sector is improved should be processed into semi-finished and finished products to extend the shelf life and thus add value for both the domestic and export markets. By this means the economy of Ghana would improve, that is GDP will increase, value will be added to the produce, more foreign exchange would be earned to improve the balance of payment and more taxes/import duties would be collected by the Government to run the country. In addition, ancillary factories would be established to service and support the processing factories, while unemployment level would be reduced and the social and living standard of the people would also improve. Though upstream processing of agricultural produce has its challenges, however, when these challenges are properly tackled and solved, the prospects gained would outweigh the challenges. In this way, Ghana's industrialization programme would have been accelerated and recognized accordingly.

Isoforms of purified N–methyltransferase from human blood platelets

F.A. Yeboah¹, M. Agyei-Frempong¹, W.A. Gibbons²

¹Department of Molecular Medicine, School of Medical Sciences,

Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.

²Department of Pharmaceutical Chemistry and University Industry Centre for Pharmaceutical Research,

School of Pharmacy, University of London, 29-39, Brunswick Square, London WC1H IAX UK.

ABSTRACT

A membrane-bound protein with N-methyltransferase activity, associated with phospholipid metabolism, has been isolated from purified human blood platelet plasma membranes. The activity of this enzyme has been detected in crude platelet preparations. However, the nature and properties of this enzyme and its purification from normal human blood platelets have not been investigated, hence, the aim of this study was to purify, characterise the enzyme from human blood platelets and determine its possible role in phospholipid transmethylation. The plasma membranes were purified by velocity and sucrose gradient centrifugation and solubilized in buffer containing 0.5% Triton-X 100. The partially purified extracts were further purified using a combination of ion-exchange chromatographic procedures, preparative IEF and preparative SDS-PAGE. The preparative rotorfor electrofocusing, using pH 3-10 ampholyte at 40EC, yielded activities at both acidic and basic pHs of approximately 3.5 and 8.5, respectively. The pH 8.5 activity yielded predominantly a single 67 KDa band on SDS-PAGE gel and the pH 3.5 activity also gave a similar band and a few lighter bands at 35 KDa and 50 KDa. The acidic and basic fractions catalysed the transfer of methyl groups from S-adenosyl inethionine to PE with a predominant formation of PME (ca 90%). The fraction purified by preparative SDS-PAGE also yielded a major methylating activity that eluted between 60-70 KDa. This latter protein was washed free of SDS and its activity measured; it, too yielded predominaly the monomethylated PE. These data are consistent with the hypothesis that several SAM-dependent isozymes also exist in human blood platelets that convert PE to PC.

Setting shrinkage strains of chemical-cured glass ionomer-based dental restorative materials

G.K. Toworfe¹ and D.C. Watts²

¹Department of Basic Dental Science, Dental School, University of Ghana,

College of Health Sciences, Korle-Bu, Accra.

²Biomaterials Science Unit, University of Manchester Dental School, Manchester, U. K.

ABSTRACT

Shrinkage strains are exhibited by the current formulations of chemical-cured dental restorative systems. In resin-modified glass ionomer systems, these have been linked to filler contents, types and quantity of monomer. Post-gelation rigid contraction that follows onset of cure leading to marginal defects is a clinically significant factor, although flow is noted to compensate for shrinkage effects during pre-gelation phase. The bonded-disk technique was employed to study the shrinkage strains of chemical-cured and light-activated glass polyalkenoate-based cements at two clinical temperatures of 37EC and 60EC over a period of 2 hours. Magnitudes of shrinkage strains obtained were subjected to one-way ANOVA and Schefe's 0.5 significant level statistical analysis. The time-dependent shrinkage strain data characteristic of the materials indicated a linear initial rigid and rapid contraction, which is appropriately represented by the Kohlrausch-Williams-Watts stretched exponential decay curve. The kinetics of shrinkage was expressed by the overall time constant and the initial contraction strains at

30 s, following the onset of cure. Data obtained after 15 minutes up to 2 hours indicated high contraction strains at 60EC compared to that at the intra-oral temperature, 37EC. There is a relatively slow development of contraction strains in glass ionomer-based systems compared to resin-based ones. This is, however, a positive quality for the glassy materials in their use as marginal seals. Nevertheless, contraction strains in dental restorative systems with their destructive shrinkage stresses remain unresolved.

Aspects of the dynamics of the inshore and offshore populations of Brachydeuterus auritus (Family: Haemulidae) in Ghana

A. Asabere-Ameyaw¹, J. Blay, Jr. and K. Yankson²

¹University College of Education of Winneba, Ghana.

²Department of Zoology, University of Cape Coast, Cape coast, Ghana.

ABSTRACT

Growth and mortality parameters of the bigeye grunt populations in Ghana were estimated from length-frequency data collected between November 1993 and October 1995. The von Bertalanffy growth parameters, L₄, K and t_o, were estimated as 23.0 cm TL, 1.20 yr^-1 and - 0.14 yr, respectively, for the inshore population, and 22.7 cm TL, 1.16 yr^-1 and -0.15 yr, respectively, for the offshore population. The growth performance index was calculated as 2.80 for the inshore population and 2.78 for the offshore population. Estimates of the mortality coefficients were: Z = 6.40 yr^-1, M = 2.14 yr^-1 and F = 4.26 yr^-1 for the inshore population, and Z = 6.40 yr^-1, M = 2.10 yr^-1 and F = 4.30 yr^-1 for the offshore population. Similar estimates of the exploitation rate (E = 0.67) were obtained for the two populations. This value exceeds the optimum (E_opt) of 0.46 and 0.57 derived by the yield-per-recruit analysis for the inshore and offshore populations, respectively. These observations suggest the over-exploitation of the B. auritus populations.

Aspects of conchological features of Anadara senilis in relation to the nature of subtratum

K. Yankson

Department of Zoology, University of Cape Coast, Cape Coast, Ghana.

ABSTRACT

Some conchological features of the bloody cockle, Anadara senilis occurring in six lagoons in Ghana were investigated in relation to the particle size of the substratum. Shell indices (i.e., shell length/ shell height, shell width/shell height and shell weight/shell height and the number of ribs on the shells of one hundred (100) specimens from each lagoon were analysed. The mean particle size of the substratum for each of the lagoons was determined and classified according to the USDA system. The substrata ranged from fine to very coarse sand. Cockles inhabiting substrates with larger particles size tended to possess slim and lighter shells with fewer number of ribs, while those in substrates with smaller particles had rotund (tumid) and heavier shells with more ribs. These results are interpreted in terms of the roles of the shell in burrowing and maintaining stability in the subtratum.

Performance of oyster (Crassostrea tulipa) spat cultured at different densities

Edward A. Obodai

Department of Renewable Natural Resources, University for Development Studies, Tamale.

ABSTRACT

This paper describes an experiment conducted in the Nakwa Lagoon (in Ghana) to determine the optimum stocking density of oyster ( C. tulipa) spat on coconut shell cultches. Six densities (1, 2, 3, 4, 5 and 6 spat per coconut shell of an average surface area of approximately 92 cm²) were tested. Performance of spat was measured in terms of growth (increase in shell height), survival and dry meat weight production at the various densities. The results indicate that growth declined with increasing stocking density, but differences in growth rates were not significant. Survival and dry meat yields, however, did not show a descending or ascending trend with increasing density. These parameters were best at stocking density of 4 spat per coconut shell. In all the three parameters studied, performance was better in the second than in the first experiment, due to the smaller mean initial size of the animals in the second experiment. It is recommended that the stocking density of 4 spat per coconut shell be used for oyster culture in the Nakwa Lagoon.

Allozyme frequency distribution patterns at two gene loci of the phosphoglucomutase and one gene locus of fumarate hydratase enzymes in nine cowpea (Vigna unguiculata (L) Walp) landraces in three agroecological zones

I. K. Asante

Department of Botany, University of Ghana, P.O. Box 55, Legon, Accra, Ghana.

ABSTRACT

Allozyme diversity at the gene loci of the Phosphoglucomutase and Fumarate hydratase enzymes were studied in cowpea landraces,with accession numbers 87/139, 87/142, 87/157, 87/30, 87/37, 87/55, 87/77, 87/81, and 87/83. Leaf protein of the accessions were extracted and subjected to starch gel electrophoresis. Two gene loci and one gene locus were assayed for phosphoglucomutase and fumarate hydratase enzymes, respectively. The two phosphoglu-comutase gene loci were designated PGM1^* and PGM2^*, with three and four alleles, respectively. The fumarate hydratase gene locus was designated FH1^* with three alleles. Mean allele frequencies for PGM1^*-1, PGM1^*-2, and PGM1*1-3 are 0.470 " 0.011, 0.389 " 0.010, and 0.134 " 0.012, respectively. Mean allele frequencies for PGM2*1-1, PGM2^*-2, PGM2^*-3, and PGM2^*-4 were 0.445 " 0.052, 0.475 " 0.038, 0.062 " 0.019, and 0.017 " 0.010, respectively. Mean allele frequencies FH1^*-1, FH1^*-2, and FH1^*-3, were 0.294 " 0.106, 0.470 " 0.085, and 0.236 " 0.064, respectively. Allele frequencies for PGM1^*-1, PGM2^*-1 and FH1*-1 were highest in the deciduous forest zone. The alleles PGM1^*-2, PGM2^*-2 and FH1^*-2 were highest in the Guinea savanna zone, while the highest frequencies for alleles PGM1^*-3, PGM2^*-3, PGM2^*-4 and FH1^*-3 occurred in the Sudan savanna zone. Alleles PGM2^*-3, PGM2^*-4 and FH1^*-3 showed cline effects with increase in their allelic frequencies from the deciduous forest zone to the Sudan savanna zone; allele PGM2^*-1 showed cline effect with an increase in frequency from the Sudan savanna zone to the deciduous forest zone.

A Thin Layer Chromotographic (TLC) detection methodology for screening herbicides using local plants and grasses

S.T. Lowor,¹ C.K. Akpabli² and P.O. Yeboah³

¹Cocoa Research Institute of Ghana, P.O. Box 8, Tafo, Akim, Ghana

²Department of Chemistry, University of Ghana, Legon–Ghana.

³Department of Chemistry, National Nuclear Research Institute,

Ghana Atomic Energy Commission, P.O. Box LG 80, Legon-Ghana.

ABSTRACT

This paper presents a Thin Layer Chromatographic (TLC) detection methodology for the qualitative and quantitative determination of herbicides, using some local plants/grasses as part of an on-going method development for providing alternative cost-effective analytical procedure for screening pesticide residues. Out of the thirteen (13) species of green leaves used in the test, the best and most sensitive were found to be Sporobulus pyramidalis and spinach with the minimum detectable quantities (MDQ) ranging from 0.125 ng/5 µL to 5 ng/5 µL, depending on the herbicide in question. Also to be discussed is an easy way of predicting which green leaves in a particular locality will be suitable for screening, as well as some results obtained from a cocoa ecosystem.

The vegetative method of propagating Adenia cissampeloides

¹Kwadwo Yeboah-Gyan and ²P.Y. Boateng

¹Department of Biological Sciences, University of Science and Technology, Kumasi, Ghana.

²Department of Horticulture, University of Science and Technology, Kumasi.

ABSTRACT

To ensure availability of plant material of Adenia cissampeloides for successful and sustainable development of its extract for subduing African honey bees, suitable methods of its propagation, including its agronomic requirements were investigated. Vegetative method of propagation was used for the experiments: cuttings from vines in an active growth phase and those from aged vines were made from the mother plant. The former cuttings were classified according to the thickness of the vines as

1 cm and 2 cm thick vines and the latter cuttings were 3 cm thick. Sprouting and rooting of unsterilized, semi-sterilized and completely sterilized cuttings grown in different soil types were grown in the greenhouse. The disease-free cuttings, which rooted and sprouted, were cultivated in plastic bags containing sterilized soil. They were transplanted after four months to experimental plot maintained in partially cultivated forest area in the University Botanic Garden. The rate of growth of randomly-selected seedlings were recorded at monthly intervals for six months after transplanting. The results of the greenhouse experiments showed that the plant could be grown successfully in different soil types, including sandy soil using cuttings from vines in an active growth phase. It was also found that minimizing contamination by cleaning and sterilizing cuttings increased their success rate in rooting and sprouting. The seedlings transplanted in the field exhibited high growth and survival rates in humid forest environment. The commercial cultivation of the plant could, therefore, be feasible and cost-effective.

Prospects of using cassava as temporary shade for cocoa in degraded areas

E.B. Frimpong, A.O. Dwapanyin, Y. Adu-Ampomah and A.A. Karimu

Cocoa Research Institute, P. O. Box 8, Tafo – Akim.

ABSTRACT

There have been significant advances in breeding for cocoa varieties with high yield in Ghana and elsewhere. The best yield so far achieved was in Malaysia, where 6000 kg. ha.^-1 year, representing only 16-20% of the yield potential of cocoa was recorded. Recent evidence suggests that yield in cocoa is source-limiting (as only 2% of cherelles pass the wilting stage) and not sink limiting. There appears to be a considerable scope for increasing yield of coca through management practices. Cocoa, in comparison to many perennial crops, has a general requirement for shade. Cocoa, therefore, is traditionally planted under mixed forest shade trees. The forest trees serve as permanent shade and plantain is usually planted as temporary shade (during establishment of new farms). However, plantain succumbs to drought in denuded areas and has proven to be unsuitable for use as temporary shade in marginal areas. It is being contended that the provision of optimal shade could maximise cocoa production. Four cassava varieties (Manihot spp.) were planted as temporary shade tree in September 1995 at three spacing (1.2 m x 0.6 m; x 1.2 m and 1.2 m x 2.4 m) at Akumadan. The level of shade provided by the canopies and the control (plantain shade) were assessed, using two matched EEL Light-master Photometers. The cocoa seedlings were transplanted at 1.2 m x 1.2 m spacing under the cassava shade treatments in May/June 1996. The experimental design was a split-plot with three replications. The results show that the survival rates of cocoa seedlings during the two drought seasons following field transplanting were improved by an average of 14% over the plantain shade with the best performing cassava variety showing 20% and the least 8%, receptively. The growth of cocoa seedlings assessed by height and girth measurements was not affected by the shade treatments. Sixty three percent of the seedlings from the cassava shade plots (compared to 48% in the control) jorquetted by the third year after transplanting, an indication of better establishment.

Preliminary observations of the economic importance of rodents in the establishment of oil palm (Elaeis guineensis) plantations in the Eastern Region of Ghana

S.O. Appiah¹ and D.K. Attuquayefio²

¹Oil Palm Research Institute, C.S.I.R., P.O. Box 74, Kade, Eastern Region, Ghana

²Department of Zoology, University of Ghana, P.O. Box 67, Legon-Accra, Ghana.

ABSTRACT

Preliminary surveys to assess the damage caused to oil (Elaeis guineensis) seedlings were conducted during the first two years after transplanting to the field. Four oil palm plantations in the Eastern region of Ghana were selected for the surveys in 1996 and 1997. A survey of the suspected rodent pests was also undertaken during the latter part of 1997. The rodents gradually chewed the succulent apical buds of the seedlings, eventually causing the death of the palm. The ultimate objectives of this survey were: (i) to assess the damage caused to the young oil palm plants by rodents; (ii) to develop the capability to identify rodent pests through the recognition of the type of damage they cause to the oil palm, and (iii) to correctly identify the rodent pests of oil palm and to investigate their general biology and ecology for effective control. The damage assessment surveys involved periodic inspections of the plantations, the recording of the number of undamaged seedlings, and calculation of annual percentage seedling losses. The rodent survey involved a capture and identification programme using Sherman collapsible live traps placed along designated transects within the plantations. Identifications were confirmed using identification keys, manuals and voucher specimens. All the rodents captured so far have been identified as Dasymys incomtus (shaggy swamp rat), which has also been observed as a serious pest of oil palm in Nigeria and La Côte d'Ivoire. The assessment of rodent damage in the designated plantations indicated a drastic rise in percentage plant destruction of between 0-3% after the first year, to 41-57% after the second year of transplanting. The need to conduct further research, and the specific areas to be investigated in order to design effective rodent management and control strategies to preserve plant stands for maximum yields, have been stressed.

Economics of intercropping food crops in oil palm for small-scale farmers

Nuertey B.N¹., Ofori K.² and Asamoah, T.E.O.

'Oil Palm Research Institute, Council for Scientific and Industrial Research, P.O. Box 74, Kade, Ghana.

²Crop Science Department, Faculty of Agriculture, P.O. Box 44, Legon, Ghana.

ABSTRACT

An intercropping food crops in oil palm experiment was conducted between 1994 and 1997 at the Oil Palm Research Institute, Kusi, to evaluate the economies of intercropping food crops in oil palm for the small-scale farmer. There were four treatments consisting of sole oil palm with pueraria cover crop; oil palm + maize + cassava, oil palm + maize + plantain and oil palm + maize + maize. Costs and benefits analyses of intercropping food crops in oil palm was done by comparing production cost and revenue for sole and the intercropped oil palm. The cost-benefit ratio in a declining order were: 3.6, 1.8, 1.6 and 0.18 for the oil palm + maize + cassava, oil palm + maize + maize, oil palm + maize + plantain and sole oil palm with pueraria, respectively. It was, therefore, economically sound at the given input and output quantities and prices to intercrop the oil palm with food crops.

Preparation and characterization of glue from animal bones

V.K. Nartey, C.K. Akpabli, S. Salahudeen

Department of Chemistry, University of Ghana. Legon.

ABSTRACT

Glues are important adhesives obtained from animal source. They find extensive use in industry, offices and the home. We find a lot of animal waste in the system that is fit for this purpose. In this work, therefore, glues were prepared using cow and sheep bones. Physical properties and chemical constituents of the products were determined. Some of these physical properties determined included viscosity, melting point, adhesive strength, keeping quality and performance. Glues from both sources showed close values for these properties. Chemical constituents determined included fat content, gelatine content, chloride and grease contents and pH of solution. Results of these values compared favourably with standards obtained from Ghana Standards Board.

The use of gamma radiation for the preservation of kola nuts

J.F. Takrama¹, J.E. Sarfo¹, P.C. Aculey¹, K. Osei-Bonsu¹,

Kojo Montford² and J. Nketsia-Tabiri²

¹Cocoa Research Institute, P.O. Box 8, Tafo, Ghana.

² Dept. of Food Science and Radiation Processing, Ghana Atomic Energy Commission,

P.O. Box LG80, Accra, Ghana.

ABSTRACT

Kola nuts wrapped with Mitragyna stipulosa (Akan: subaha) leaves and stored in baskets (traditional method) and irradiated with Co-60 gamma rays with absorbed doses ranging from 0.10 to 0.50 kGy at a dose rate of 0.171 kGy/hr to control kola weevils (Balanogastris kolae) during storage. The number of nuts per treatment ranged between 20 and 1353, and the ambient storage temperature fluctuated between 16.5EC and 37.5E C. Gamma radiation suppressed the development and emergence of kola weevils that destroy the nuts in storage. Whilst no live insects were found in the treated samples, up to 48 live weevils were counted per packet in the control treatment at 28 days in storage. Consequently, nut infestation in the control was about 98.4%. Fungal deterioration of both irradiated and unirradiated kola nuts was observed. Weight loss in kola nuts irradiated at 0.25 and 0.50 kGy and stored for 84 days after irradiation was 18.2% and 19.2%, respectively, whilst comparable loss from the control treatment was 39.9%. Weevils fed with treated and untreated nuts did not show any preferences and differences in growth. A panel of tasters did not detect any differences between treated and untreated nuts.

Radio-sterilization effects on adult males of Glossina tachinoides (Diptera: Glossinidae) exposed to different doses from a gamma irradiation facility in Ghana

C.E. Annoh¹, D.A. Adabie-Gomez¹, I. Ennison² and G. Emi- Raynolds²

¹ Department of Animal Science,Biotechnology and Nuclear Agriculture Research Institute (BNARI) P.O. Box AE 50, Atomic Energy, Accra, Ghana.

² Radiation Technology Centre (RTC), National Nuclear Research Institute (NNRI)

P.O. Box LG 80, Legon, Ghana.

ABSTRACT

Induced sterility of adult males of Glossina tachiniodes irradiated with gamma doses of 130, 150 and 160 Gy, respectively, in air was investigated. The flies were irradiated at horizontal distances of 50 cm and 70 cm, respectively from the Gamma Facility. The mean percentage insemination of spermathecae ranged between 82.83 " 2.8% and 74.63 " 2.8%. All females mated and inseminated with irradiated males produced large numbers of aborted eggs and very few viable pupae. At optimum dose range between 150 Gy and 160 Gy at 50 cm horizontally from the gamma source, irradiated G. tachinoides males could achieve fertility of less than 5% (i.e., 3.7% and 0.7% fertility, respectively).

Dynamic feedback characteristics of Ghana Research Reactor-1

E.H.K. Akaho, S. Anim-Sampong, B.T. Maakuu and D.N.A. Dodoo-Amoo

Department of Nuclear Engineering and Materials Science, National Nuclear Research Institute, Ghana Atomic Energy Commission, P.O. Box LG80, Legon, Accra.

ABSTRACT

Dynamic experiments were performed to investigate the effects of insertions of step and ramp reactivities on Ghana Research Reactor-1. These safety performance tests of the reactor show that the reactor is inherently safe. The peak powers were found to be low and could not lead to damage of fuel meat and cladding. The radiation levels associated with these releases were monitored to be safe for the operation of the equipment and personnel. The maximum temperatures of the coolant were also far below the saturation temperature and no boiling crisis was expected within the flow channels of the reactor.

A review of the Phytophthora pod rot disease situation in Ghana

A.Y. Akrofi

Cocoa Research Institute of Ghana, P.O. Box 8, Tafo-Akim.

ABSTRACT

The presence of Phytophthora megakarya, which until 1985 was unknown in Ghana, has changed the status of black pod disease of cocoa in the country. Hitherto, only Phytophthora palmivora was known to be present. This paper reviews the Phytophthora pod disease situation, the origin, distribution, incidence and damage caused by P. palmivora and P. megakarya, the two known causal pathogens of black pod disease in Ghana. It also discusses attempts being made to address the problem in relation to the epidemiology of the disease.