Theses and Dissertations Collection

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Genetic interaction between phaseolus vulgaris and bean common mosaic virus with implications for strain identification and breeding for resistance
(Wageningen, 1978) Drijfliout, E.
DRIJFHOUT, 嚣 TEic Mus with implications for strain identi^-aHon^nd^breeding for resistance. RepJVerllJandbouwk. Onderz.) 872. ISBN 90 220 0671 9. (vii) + 98 p.. summaries. 仙*撷 , 2 加*4两加卅、 Aho: Doctoral thesis, 'Vageningen^ } Various strains of bean common mosaic virus (BCMV) occur in susceptible cultivars of bean. To compare compare these strains, a standard procedure for identification ;ind a set of dif- bean. To ferentiM cultivars were established. The differentials are representatives of 11 resistance Roups'determined groups, < ---------- --- by testing - of about 450 lx?an cultivars with 8 to 10 strains. The virus strains and isolates were classified into 10 pathogenicity groups and subgroups, so that 10 strains were distinguished and the others considered as isolates of those strains. Twelve differentials were intercrossed and their F, and tested with most of the strains for genetical analysis of resistance in bean. Seven genes were distinguished: a necrosis gene /, already known from the literature. 5 strain-specific resistance guncs be』, be」,bc・2, bc-22 and bc・3, and a strain-unspccific gene be*, complementary to the strain-specific ones. Genes hc-1 and he-12 were allelic, as were bc・2 and bc・2:. The 5 loci segregated independently or nearly so. The 4 strain-specific genes bc・l to hc-22 had a gcnc-for-gcnc relationship with 4 pathogenicity genes, likely to be present in the virus strains. Gene bc-3 had not been overcome by a corresponding pathogenicity gene. Two bean genotypes were developed with resistance to all known strains. Some implica tions for resistance breeding arc discussed. Free descriptors: Phaseolus vulgaris, common bean, bean common mosaic virus. BCM V, breeding for resistance, genetics of resistance, iiost 一 virus relationship, pathogenic varimion, screening for resistance, strain identification. This thesis will also be published as Agricultural Research Reports 872. ® Sc 血 Agricultural Publishing and Documentation ,Wageningen, 1978. No Part of this book may be r:r._. rint, micro- reproduced and/or published in any form, by print, photop film or any other means without wri -• written permission from the publishers.
Nutritional evaluation of sorghum as affected by germination with main reference to dietary bulk and protein quality
(Sokoine University of Agriculture, 1984) Mosha, Alexander Clemence
The nutritional value of sorghum as affected by germination and different dehulling techniques was studied with emphasis on protein quality, dietary bulk and food intake. Two low-tannin and two high-tannin varieties were investigated. Nutrient content was affected by germination: minor changes occurred in proximate composition, except for a significant decrease in oil in all varieties. Thiamine, riboflavin and niacin content increased. Lysine increased in all varieties and the other essential amino acids in creased marginally. Dietary fibre was unaffected. Tannin content decreased significantly. Traditional and abrasive dehulling decreased the amount of protein, oil, dietary fibre, minerals, tannins and phytic-phosphorous. protein digestibility was Nutrient availability measured in vitro: significantly higher in the low-tannin varieties. Germination and dehulling increased digestibility in all varieties. Cooking reduced protein digestibility in the high-tannin varieties and significantly more than in the low-tannin cultivars. Iron availability was low in all varieties and increased only in one high-tannin variety after germination. Nutrient availability measured in vivo by rat-bio-assay: protein digestibility was high in low-tannin cultivars but low in high-tannin varieties. Germination increased digestibility only in one high-tannin variety. Biological values were higher in the high-tannin varieties. BV and NPU were not affected by germination. In vivo iron availability was higher in the low-tannin varieties and was increased by germination in only one of the high-tannin varieties. Zinc availability was low and was unaffected by germination and tannin content. Dietary bulk and food intake: When preparing weaning gruels, three times as much germinated flour of the low-tannin varieties, as compared to ungerminated, could be mixed into the same volume, while maintaining the same consistency of the gruel. Germinated flour of high-tannin varieties did not have this effect. Addition of 5% germinated low-tannin sorghum flour (enzyme-rich) to thick ungerminated gruels reduced the viscosity to acceptable weaning food consistency. This method of reducing dietary bulk of weaning food was accepted and used by mothers at village level. Food intake by 12-48 months old preschool children was significantly higher for bulk-reduced low viscosity gruel with 20% solids, compared to untreated gruel. It was concluded that sorghum nutrient content is comparable to other cereals except for the high tannin content. Germination generally improves nutritional value through increased lysine, better protein digestibility and reduction of anti nutritional factors, mainly tannins. The use of bulk-reduced high nutrient density weaning foods could eventually improve the nutritional status of young children.
Processing of cassava, residual cyanogens and mycotoxin content in traditionally processed cassava products
(The University of Reading, 1998-04) Muzanila, Yasinta C.
Cassava samples from some villages in Tanzania processed by wet fermentation, solid state fermentation and sun drying were analysed for residual cyanogens and presence of mycotoxins. Cassava samples (bitter varieties) processed by wet and solid- concluded that wet fermentation is very effective in reducing cyanogens in cassava. No mycotoxins (aflatoxins ) were detected in cassava samples. The chemical composition of these cassava samples was also determined. Wet fermentation showed lower content of vitamin C, reducing sugars and protein compared to samples processed by solid state fermentation and sun drying. In another experiment, cassava flakes were produced on a drum drier using varying pre cooking temperatures and drum speeds. Pre-cooking conditions were: no pre-cooking, pre-cooking at 75°C for 35 minutes and 100°C for 5 minutes. The drum speeds used were 11.5 and 14.0 r.p.m. which correspond to 4.0 and 3.4 seconds drying time respectively. The flakes were analysed for vitamin C, moisture, free starch, reducing sugars and protein content. Pre-cooking conditions affected vitamin C, moisture and free starch content while Hmm speed affected only the moisture content of the flakes. Prolonged pre-cooking time caused losses in vitamin C while pre-cooking at the higher temperature increased free starch content of the flakes. The moisture content increased with increasing drum speed. The soluble amylose test showed that starch retrogradation occurs when cassava is cooled after the pre-cooking stage. The textural characteristics of reconstituted mash from the flakes was analysed using the Texture Analyser, after adding emulsifiers (stearate monoglyceride, sodium caseinate and skim milk powder). Results from Texture Profile Analysis (TPA) (adhesiveness), tests showed that stearate monoglyceride Back extrusion and sensory evaluation emulsifier reduces the stickiness of reconstituted cassava flakes mash. The Differential Scanning Calorimetry (DSC) thermograms indicated the formation of an amylose monoglyceride complex. Cassava samples with stearate monoglyceride had low water absorption capacity and high bulk density. Also sample with stearate monoglyceride had low viscosity according to the results from the Brabender amylograph tests. Samples of cassava flakes and reconstituted mash with skim milk powder and sodium caseinate were darker in colour compared to those with stearate monoglyceride according to the results from both instrumental (Hunter Lab spectrophotometer) and sensory tests.
Improvement of the dehulling efficiency of sorghum and millet
(University of Newcastle upon Tyne, 1999-12) Lazaro, Ezra Lyimo
Methods for improvement of the dehulling efficiency of sorghum and millet were investigated. These included: studying the fundamental physical and mechanical properties of the grain and how these properties are influenced by different process variables, the use of different pre treatment methods to loosen the grain seed coat and hence facilitate its removal during the dehulling process, the use of alkali dehulling as an alternative method to conventional abrasive and traditional dehulling methods, development of a numerical model which could be used as a tool for further study of the abrasive dehulling process and finally development of a prototype dehuller combining dehulling principles from both traditional and mechanical dehulling systems which could dehull tempered grain without problems experienced in current mechanical dehullers. The effects of grain and process variables, such as moisture content, temperature and loading conditions on mechanical properties of grain were studied under uniaxial compression of individual whole grain kernels. Five temperature and moisture dependent parameters, which included modulus of deformability, ultimate strain, ultimate stress, energy to break point, force to break point and modulus of toughness were evaluated from force-deformation relations obtained. Each of these parameters except ultimate strain decreased with increase in kernel moisture content and temperature. Grain strength properties also depended heavily on the orientation of the grain during loading (flat loading vs. side loading), indicating that sorghum kernel was anisotropic with respect to mechanical properties. Effect of different pre-treatments on dehulling efficiency was investigated using hydrothermal pre-treatments. These included, treating the grain with steam or tempering with distilled water for different durations followed by drying using either unheated ambient air at 20°C or heated air at 60°C to their initial moisture content (12%db). A tangential abrasive dehuller was used to dehull the pre-treated grain and the effect of different pre-treatments on dehulling efficiency of the pre-treated grain was evaluated based on the extent of seed coat removal and crude fibre reduction in the dehulled grain. Results indicated that hydrothermal pre-treatments improved the dehulling efficiency of sorghum and millet by an average of 8.5% and 20% respectively in terms of seed coat removal and by 16% and 13.7% respectively in terms of crude fibre reduction in the dehulled grain compared to untreated grain. Tempering the grain for a short duration (<15 minutes) reduced the seed coat adhesion in sorghum and millet substantially without affecting the grain strength properties significantly. Seed coat adhesion strength at different tempering durations was quantified by measuring the tangential force required to remove a unit area of seed coat using a friction apparatus. Tempering for 15 minutes reduced the seed coat adhesion strength per unit area by 91.1% and 95.7% compared to untreated grain for sorghum and millet respectively. The effect of seed coat adhesion reduction due to tempering, however, was reversible as the grain kernel was dried. I Alkali dehulling of sorghum and millet was investigated using an aqueous solution of sodium hydroxide as a dehulling agent. Results indicated that alkali concentration, soaking time and temperature were significant factors during the dehulling process. Soaking the grain in 10% aqueous solution of sodium hydroxide for 10 minutes at 60°C was found to be the optimum alkali dehulling conditions for sorghum and millet. Under these conditions 90% yield of unbroken endosperm at 89% dehulling efficiency was achieved from a soft red sorghum variety, which is higher than can be achieved using any of the conventional dehulling systems. Moisture absorption characteristics of sorghum and millet during tempering were studied at different temperatures, initial grain moisture contents, and endosperm textures. Temperature had a significant effect on moisture absorption characteristics of both sorghum and millet, moisture absorption increased with increase in temperature for both sorghum and millet. The moisture absorption characteristic was modelled using Fickian diffusion model and Peleg's model. Peleg’s model was able to simulate the moisture absorption characteristics of both sorghum and millet at initial soaking stages more accurately than the Fickian diffusion model. A general model, based on Peleg’s model and Arrhenius function, was developed for prediction of tempering duration at different temperatures within 20 - 50°C temperature range. The abrasive dehuliing process was successfully modelled using a three-dimensional discrete element model. The computer code was validated by experiment, and good correlation was obtained between simulation and experimental results. Several numerical experiments were also carried out using the developed computer code to investigate the influence of mill and grain parameters on dehulling of sorghum and millet. This model thus provides a tool which can be used to study the dehulling process in more detail than is currently possible using other methods. Based on experimental results from the grain physical and mechanical property and pre treatment tests, a prototype dehuller incorporating a dehuliing surface, which enabled it to dehull moist grain without clogging, was designed and constructed. Grain-grain and grain- dehuller surface friction was the main dehuliing principle. The dehuller was able to achieve higher yield, dehulling efficiency and colour reduction tangential abrasive dehuliing device (TADD).
Nutritional status and socio-economic problems of adolescent pregnant girls: A case study of Morogoro, Coast and Dar es salaam regions
(Sokoine University of Agriculture, 2002) Shirima, Candida Philip
Adolescence is a distinct and dynamic phase of development and considered to be the period between 10 and 19 years of age. It marks the onset of puberty. In some communities, it means the girl child is ready to engage in marital affairs and bear children. This dissertation presents the results of a study conducted in Temeke, Kibaha and Morogoro districts to examine the socio-economic factors and nutritional problems of adolescent pregnant girls. Specifically, the study examined prevalence of adolescent pregnancies, factors contributing to early pregnancies, problems faced by pregnant adolescent girls, pre-pregnancy nutritional status, nutritional status during pregnancy and pregnancy outcome. Primary data were collected from 180 pregnant adolescent girls and 600 non-pregnant adolescent girls. Nutritional status was assessed by anthropometric and biochemical methods. Statistical Package for Social Sciences (SPSS) was employed to analyse the data. Prevalence of adolescent pregnancy was found to be 21.5% for Temeke district, 19.5% in Kibaha district and 17.7% in Morogoro district. Factors identified to contribute to early pregnancy are: traditions and culture of initiation rites, lack of knowledge on family planning, fear of side effects associated with family planning methods and economic hardship among adolescent girls. It was further observed that adolescent girls encounter many problems such as unplanned pregnancies and marriages, dropout from school, late detection of pregnancy, late antenatal visit to detect any abnormalities, rejection by their partners after conception, and economic dependence.
The role of social capital in coping with household food insecurity in urban areas of Tanzania: the case of Dar es Salaam and Morogoro municipality
(Sokoine University of Agriculture, 2003) Sango, Danford
This study was conducted to investigate the role played by social capital in coping with household food insecurity in urban areas of Tanzania. The study entailed surveys conducted in Dar es salaam city and Morogoro municipality. Specifically the study had four objectives namely (a) to identify the various coping options related to social capital that are commonly adopted by households in the study area to contend with food insecurity (b) to determine the characteristics of social capital arrangements which are relevant to household food security (c) to determine the extent to which social capital reduces household food insecurity vulnerability and (d) to determine the effects of household stock of social capital on household income. The study is based on a survey of 180 households. Proportionate stratified random sampling technique was used to select respondents across all income levels in the study area. The data were coded and analysed with the aid of the Statistical Package for Social Sciences (SPSS) computer programme. Data analysis entailed a number of descriptive statistics including frequencies, cross tabulations and chi-square tests. However, regression analysis was the major parametric test employed. The regression analysis made use of, first, a multiple linear regression model aimed at testing the effect of social capital on household income and, second, a logistic regression model which tested the effect of social capital on household food vulnerability. Results revealed that the major food insecurity coping strategies based on social capital commonly adopted by urban households were food purchase on credit, borrowing of money, food offers, reliance on informal credit, money offers, labour sales and exchange of assets for food. The study has also revealed that social capital significantly increases household income in the study area (p<0.05) but did not significantly reduce household food insecurity vulnerability (p>0.05). In addition, some characteristics of the identified social capital based coping strategies were uncovered. Whereas food purchase on credit was a characteristic of the poor and food vulnerable households, borrowing of money was practised by both low and medium income households. On the other hand, lack of social capital was not a major factor restricting low income households from accessing food on credit or getting money offers. Borrowing of money was common among close friends and neighbours while, food and money offers mainly took place between non-blood and blood relatives, respectively. In view of the findings from this study, a number of policy implications are recommended. Development policies ought to advance and nurture social capital strategies commonly used by society in coping with food insecurity. It is also clearly apparent that there is a need for prioritising and clearly targeting beneficiaries of food assistance aimed at reducing food insecurity vulnerability in urban areas. Overall the study strongly alerts on the fact that incomes of urban households are significantly low rendering food items unaffordable.
Nutritional quality of low-cost supplementary foods for supporting growth and rehabilitation of undernourished populations in Tanzania
(Michigan State University, 2004) Mosha, Theobald Conrard Edward
Severe undemutrition during childhood remains a common health problem in many parts of the world and contributes immensely to childhood morbidity and mortality. According to WHO/UNICEF, producing low-cost, ready-to-feed, nutritious foods from locally produced ingredients by using low-to-medium level technologies in local settings can considerably help mitigate child undemutriton through increased access to food. The aim of this study was to formulate, process, and evaluate the quality of processed, ready-to- feed bean-based composite supplementary foods for pre-school age children in low- income populations in Tanzania. Supplementary foods based on cereal-bean-sardine mixtures were formulated from ingredients produced locally in Tanzania. The products were formulated to maximize the amino acid score as recommended by the FAO/WHO/UNU for pre-school age children and to provide the desired amount of energy and fat as stated by the FAO/WHO Codex Alimentarius guidelines (CAC/GL 08-1991) for supplementary foods for older infants and young children. Red beans {Phaseolus vulgaris), com/maize {Zea mays), rice {Oryza sativa), sardines {Sardinops melanosticta) and red palm oil {Elaeis guineensis) were formulated into single/multi-mix diets and processed into ready-to-feed powders by extrusion, drum-processing and conventional cooking. The processed products were evaluated for true protein digestibility, net protein retention ratio, protein digestibility-corrected amino acid scores (PDCAAS), amino acid profile, residual phytohemagglutinins, trypsin, chymotrypsin, and a-amylase inhibitors. Foods were also evaluated for potential to support normal growth and for rehabilitation of undernourished children using a weanling rat model. Furthermore, the products were evaluated for storage stability at 38°C. The studies showed that com-bean-sardine, sorghum-bean-sardine and rice-bean sardine products had superior nutritional value compared to individual cereals or cereal + bean blends. The composite products had high true protein digestibility, ranging from 82 - 93%, high ratio of net protein retention ranging from 0.86 - 0.92 and PDCAAS ranging from 77 - 89%. The composite products also showed a good potential to support growth and rehabilitation of undernourished animals. Extrusion and drum-processing thoroughly cooked the foods as characterized by high gelatinization rate (95 - 100%) and low residual urease activity levels (< 0.05 units per 100 g food). They were also effective in inactivating the phytohemagglutinins (91 - 97%) and the anti-nutritional factors - trypsin, chymotrypsin and a-amylase inhibitors. Extrusion and drum-processing also resulted in products that had high protein digestibility and PDCAAS. During storage at 38°C, the food pH and total acids did not change significantly (p > 0.05). The products were shelf stable for at least 16 weeks.
The effect of local cassava processing methods on nutritional and sensory attributes of cassava flour: a case study of Newala district
(Sokoine University of Agriculture, 2007) Majaliwa, Nuria
A study was carried out in Newala District to investigate the effect of different local cassava processing methods on cyanogenic glucosides level, nutrient retention and colour of cassava flour. Specifically the study was aimed at identifying different local cassava processing methods, examining the effect of local processing methods on residual cyanogenic glucosides in the cassava flours, examining the effect of local processing methods on nutrient retention and color of cassava flour and study the cassava processing and production constraints in the study area. In each study site, information was obtained by focus group discussion, structured questionnaire from 40 households in each village. Samples were collected for laboratory analysis. Results showed high total residual cyanogen levels of about (790 ± 107 mg HCN equivalent/Kg dry weight) and (263 ± 71 mg HCN equivalent/Kg dry weight) in flour obtained from both small-size and large-size niakopa respectively. Cyanohydrin levels were higher (39 ± 5 mg HCN equivalent/Kg dry weight) in Chinyanya compared to levels of about (7 ± 2 mg HCN equivalent/Kg dry weight) in the flour from large size makopa. Chinyanya showed to contain (75 g/1OOg, starch, 1.3 g/1OOg protein, 32.8 g/1OOg vitamin C, 18.7 g/1OOg moisture and 13.22 pH, Makopa showed to contain 80.0 g/1OOg starch, 2.72 g/1OOg protein, 24.52 g/1OOg vitamin C, 12.5 g/1OOg moisture, at pH 10.28 where as fermented root showed to contain 65.2 g/1OOg starch, 0.75 g/1OOg protein, 15.4 g/1OOg vitamin C, 13.7 g/1OOg moisture, pH 5.25). These findings confirmed that direct sun-drying of cassava roots is an ineffective method for removal of cyanogenic glucosides as it yields products with relatively high residual levels of cyanogenic glucosides while fermentation of cassava root is an effective method in removal of total glucosides. Apart from colour preference, this study concluded that although wet fermentation showed high nutrient loss, from the health point of view it is an effective way of reducing cynogenic glucosides level from cassava root, which are dangerous for human health.
Assessment of iodine status of school children, pregnant and lactating women in mufindi and kilosa districts
(Sokoine University of Agriculture, 2008) Sakina, H
This study was conducted to assess iodine status of school-aged children, pregnant, lactating and normal women in Rungemba, Kitelewasi, Kinyanambo and Berega villages. Data were collected by using a structured, pre-tested questionnaire. Urine and salt samples were collected and analyzed to determine iodine concentrations. Anthropometric measurements including weight and height and records of age, sex and gestation age for the pregnant women were also taken. Data were analysed by using EPI info and SPSS statistical package for window programs. Results showed that, the median urinary iodine concentration for schoolchildren were 132.7 μg/L (boys) and 96.3 μg/L (girls). For pregnant, lactating and normal women, median iodine concentrations were 188.6, 155.7 and 258.4 μg/L, respectively. More than 80% (n = 135) of salt samples collected from the households had iodine concentration levels in the range of 20-50 ppm, while 15.6% (n = 135) had iodine concentrations below 20 ppm. This implied that, iodine concentration in most of the salt samples was adequate. Results also revealed that, 30.9% (n = 144) of schoolboys and 32.3% (n = 127) of schoolgirls had normal weight for age while 4.2% (n = 144) of schoolboys and 4.7% (n = 127 of schoolgirls were severely underweight. Majority 97.3% (n = 144) of schoolboys and 96.9% (n = 127) of schoolgirls had normal weight for height. Likewise, 4.3% (n = 139) of pregnant, 41 % (n = 139) of lactating and 22.3% (n = 139) normal women had BMI within the normal range (18.5 - 24.99) while 0.7% (n = 139) of pregnant, 12% of lactating, and 8% of normal women were overweight. Nutrition education on effects of iodine deficiency disorders and quality control of iodine levels in salt at district and local levels is important to ensure that adequate iodine is reaching the people.
Study of suitability of cassava and cowpea flours for making bread
(Sokoine University of Agriculture, 2008) Vilanculos, Serafina Lídia
This study was done in Tanzania and Mozambique to assess the effect of cassava and cowpea flours singly and in combination in bread making and the degree of acceptability of the bread. Five to 20% cassava and 5 to 30% cowpea were used as wheat flour diluents. As the amount of diluents increased, the loaf volume decreased. The bread size ranged from 560 ml for 30% cowpea bread to 890 ml for 100% wheat bread and from 420 to 620 ml for the pan bread, the highest value being for whole wheat bread and the lowest for 30% cowpea composite bread. The bread weight increased for cowpea composite bread and the combination cassava-cowpea composite breads, ranging from 214 to 250 g for wheat bread and from 260 to 290g for pan bread, the highest values being for 30% cowpea bread and the lowest for 5% cassava composite bread. The specific loaf volumes were 2.39 to 4.07 ml/g for wheat breads and 1.45 to 2.31 ml/g for the pan type breads. Baking losses decreased as the amount of cowpea increased. However, cassava inclusion showed no decrease in baking losses. Cassava composite breads decreased protein content but increased mineral content. Cowpea bread had increased nutrients. The 30% cowpea bread was least accepted as also reflected in the lowest buying preference. For the pan bread, the lowest value was for the combined 10% cassava-5% cowpea bread and the highest value for 10% cowpea bread. This study concluded that up to 15% substitution, the formulation results were promising. Beyond 15% there were changes in organoleptic attributes and poor gas retention reduced loaf volume. Incorporation of cassava or cowpea flour gave a compact structure at higher substitution levels. Increasing levels of cowpea flour in the blends resulted in increased ash and protein and colour changes. The nutrient gains when cowpea is used in composite flour formulation need exploitation.
Genotyping sorghum germplasm in Tanzania using microsatellite markers
(Sokoine university of Agriculture., 2008) Sallu, Raphael Samwel
Microsatellite markers are increasingly being used in crop plants to discriminate among genotypes and as tools in marker-assisted selection. In this study microsatellite markers were used to quantify the genetic diversity within as well as among 200 accessions sampled from sorghum germplasm collection at Tanzania National gene bank germplasm collection of sorghum. Although all methods did not provide similar description of relationships between accessions, there existed some consistency in discriminating accessions which are closely related and the ones which were distantly related. But, considerable variation was found at the 39 microsatellite markers analysed, with an average number of alleles per locus equal to 9.49 within accessions, the lowest was 2.0 from Xtxp114, Xcup61 and the highest number of allele was 25 as for Xgap206 marker. The collection of sorghum appeared moderately structured genetically with about 59% of the average gene diversity occurring among accessions. The SSR markers were moderately polymorphic, with diversity indices ranging from 0.07 to 0.91 with mean of 0.55.The UPGMA dendrogram based on SSR marker data clearly discriminated among clusters, even though some consistency in classification was observed among clusters. However, differentiation among morphologically accessions of sorghum, or among geographic origins, accounted for less than 35% of the total genetic diversity. Data in this study demonstrated that accessions of Tanzania sorghum contain a great deal of genetic diversity as indicated by the observed number of alleles. These results are in global agreement with those obtained previously with allozyme markers. It was also possible to show that microsatellite data are useful iniii identifying individual accessions with a high relative contribution to the overall allelic diversity of the collection. Therefore, from the result outcome the inventory was compiled that will be used in future to characterize the rest of the sorghum germplasm and make use of the identified potential parental genotypes for mapping populations and marker assisted selection programs.
Basal Metabolic Rate and energy cost of performing farm activities in Magubike village, Kilosa District, Morogoro, Tanzania
(Sokoine University of Agriculture, 2008) Ocan, Hilda Ndanguzi
Determination of basal metabolic rate (BMR), energy cost of various farm activities, physical activity level (PAL), total energy expenditure (TEE), nutritional status and work capacity (VO 2 max) was done to examine their influence on farmer’s productivity. A cross sectional study involving 64 farmers was conducted on randomly selected households. Energy expenditure measurements were determined using the Douglas bag technique, VO 2 max was measured by the Rockport fitness test and nutritional status was assessed by BMI and Hb concentration. Analysis was done using student t - test, correlation analysis and regression analysis. Men’s BMR was 4.7± 1.12MJ/day while that of women was 4.34 ± 0.77 MJ/day. Farmers mean PAL was 2.13 ± 0.26. TEE in men was 10.24 ± 3.1 MJ/day and that of women was 8.57 ± 2.1 MJ/day. BMR, PAL and TEE were all higher in men than women. The measured energy cost of digging and weeding were 6.56 ± 1.25 kcal/min; 5.67 ± 1.28 kcal/ min in men and 6.60 ± 1.49 kcal/min; 6.21 ± 1.38 kcal /min in women. Women had a higher BMI (22.4± 3.7) than men (20.9 ± 2.1). Increase in BMI was associated with decrease in percent FFM (r = - 0.811, P < 0.01) but an increase in FM (r = 0.812, P < 0.01) and percent FM (r = 0.914, P < 0.01). VO 2 max of males (45 ± 6.54 ml/kg/min) was higher than females (36± 6.49 ml/kg/min). Haemoglobin (Hb) concentration was the highest predictor of VO 2 max at 39 %. The energy expenditure of rural farmers is high and can be used to determine energy requirements. Work capacity is determined by their nutritional status (BMI, Hb concentration and body composition). Therefore, emphasis on good nutrition and provision of nutrition education remains crucial to farmers whose livelihood depends on physical strength in agriculture production. Furthermore, energy expenditure studies are necessary to validate appropriate energy requirements for farmers in Tanzania
Effect of childcare practices on the nutritional status of children aged 6-24 months in Morogoro Urban and Kilosa Districts
(Sokoine Universitry of Agriculture, 2008) Charwe, Deborah.D
The purpose of this study was to assess the effects of childcare practices on the nutritional status of children aged 6-24 months in Kilosa and Morogoro Urban districts. A sample of 300 mother-child pairs was randomly selected and interviewed using a structured, pre-tested questionnaire. The data were analyzed using the Statistical Package for Social Sciences (SPSS) software. The study revealed that, some of the socio-economic characteristics such as marital status, family size, education of the mothers, source of income, sex and age of the child had a positive effect on the nutritional status of the children. About 76.1% (n=285) of the children were currently breastfeeding. Majority of mothers (75%) started breastfeeding immediately after delivery i.e. first hour post delivery. The prevalence of exclusive breastfeeding was 24.4%, however the frequency of feeding of the children was lower than the recommended 5 times/day. There was high immunization coverage (98%) and growth monitoring visits. The study also revealed that, most of the mothers (98%) delivered their babies in health facilities and were assisted by trained medical personnel during delivery. In addition, the diseases which were associated with unhygienic conditions namely diarrohea (35.3%), running nose (37.9%), cough (38.2%) and vomiting (16.8%) affected many children compared to malaria (4.6%) and fever (40.4%). Poor nutritional status was more prevalent among the children aged 19-24 months. Prevalence of stunting in Morogoro urban and Kilosa districts were 15 and 18% respectively, however the prevalence of underweight was slightly lower in Morogoro urban (14.5%) than Kilosa district (14.9%). The study alsoiii revealed that, nutrition education intervention for the mothers improved significantly their child-care practices related to breastfeeding, feeding frequency, personal hygiene and hygiene of the general environment. It was concluded out of the study that, mothers should be educated and encouraged to start the antenatal clinic early month) and whenever possible, they should start the pre-natal clinic before conception. This will help in advising them on appropriate care practices during gestation e.g. appropriate weight gain based on pre-conception BMI.
Soybean cultivars milk yield and relative acceptability of their flavoured soy-milk
(Sokoine University of Agriculture, 2008) Msasalaga, Lazaro Henry
The objectives of this work were to study soybean cultivars milk yield and the acceptability of their flavoured soymilk. Whole soybeans varieties (TGX 1895-49F, TGX 1876-4E and TGX 1895-33F) were analysed for proximate composition, selected micronutrients and milk yield. The whole soybeans protein contents, with iron contents in brackets, for TGX 1895-33F, TGX 1876-4E and TGX 1895-49F were 43.998% (6.953 mg/100 g), 37.015% (19.670 mg/100 g) and 33.825% (10.580 mg/100 g) on dry matter basis respectively. Similarly the milk from the three varieties was analysed for proximate composition and selected micronutrients including P-carotene. The respective percentage milk yield for varieties TGX 1895-33F, TGX 1895-49F and TGX 1895-4E were 66.516, 66.063 and 56.122. These were found to be significantly different. The soymilk protein contents, with iron contents in brackets, for TGX 1895-33F, TGX 1876-4E and TGX 1895- 49F were 4.499%w/v (9.569±1.868 g/100 g), 3.516%w/v (4.755±0.147 mg/100 g) and 4.271%w/v (4.072±0.057 mg/100 g) respectively. These together with moisture, oil, fibre, carbohydrates, ash and P-carotene were found to be significantly different. It was observed that the variety that contained the highest amount of protein had the highest iron and P-carotene. There was no significant difference among samples in calcium, zinc and copper content. Energy content for each of the three varieties was calculated. The milk yield, proximate and micronutrient data were ranked using Excel software to identify two suitable cultivars for efficient production of soymilk. The primary, secondary and tertiary selection criteria were milk yield, protein content and iron content respectively. After ranking, the milk from the two varieties (TGX 1895-33F and TGX 1895-49F) was fortified with three flavouring agents (vanilla, banana and pineapple) each at three levels i.e. 0, 0.015% and 0.030% with the 0 level serving as a control. Fortified products were assessed for colour, taste, aroma, mouth feel and overall acceptability on a 5 point hedonic scale. Sensory evaluation results showed that of the three artificial flavours, pineapple flavour was the most effective compared with vanilla and banana flavour. The effectiveness was found significant (p<0.05) on the aroma and overall acceptability of soymilk with scores increasing with increasing level. Effectiveness was non significant (p>0.05) for colour, taste, and mouth feel. However, general comments were made by most panellists on the addition of sugar to improve taste. It was concluded in this study that TGX 1895-33F is the most effective cultivar for efficient production of soymilk and pineapple flavour being the most acceptable flavouring agent for soymilk.
Socio-cultural factors influencing attitudes and perceptions on food and nutrition in Morogoro municipality
(Sokoine University of Agriculture, 2009) Chacha, Mutiba Esther
The present study was undertaken to understand socio-cultural factors influencing attitudes and perceptions on food and nutrition of adult men and women residing in Morogoro Municipality. Specifically, the study aimed at determining the socio-cultural factors influencing attitudes and perceptions on food and nutrition; to assess the influence of socio-cultural factors on dietary pattern in the study area; to evaluate household decision making on food accessibility; and to assess the nutritional status of adult household members. Face to face interview and focus group discussion were used to explore the factors. Also, anthropometric dimensions of the respondents were measured, and households were visited for direct observation. A total of 534 respondents were interviewed and the nutrition status of 500 respondents was assessed. The main finding of the study indicates that most of the people in the study area (88%) attained primary school education. The majority of respondents (96%) were involved in agriculture activities. A high proportion (66%) of the respondents lack knowledge on food and nutrition. The nutrition status of the respondents explains the prevalence of under nutrition. About 69% of assessed male and 31% of female respondents are underweight using the standard BMI cut off of 18. Moreover, socio-cultural factors influenced the subjects’ attitudes and perception on food and nutrition. The study concluded that there is an inverse relationship between socio-cultural influences and eating behaviour of the people in Morogoro Municipality. Through interaction, people adopt different culture but they do not completely lose their culture, still adhere to their old traits therefore interventions need to be geared towards different groups of the population focusing more on factors influencing their attitudes and perception on food and mark the basis for planning culturally sensitive interventions to promote healthy eating.
Consumer preference and acceptability for sweet potato varieties in the lake zone of Tanzania
(Sokoine university of agriculture, 2009) Kihinga, Theresia John
The study was carried out to evaluate consumer preference and acceptability for sweet potato in the Lake Zone. Genetic yield, farmers and consumers preference, sensory acceptability, effect of processing methods on nutritional qualities and marketing channels of sweet potato were evaluated using six sweet potato varieties; two white and four orange- fleshed local and new introduced cultivars. Results showed that there were several sweet potato varieties grown in the area mostly landraces and had yield differences. Sekondari variety had the highest yield of 4.8 t/ha and Polista the lowest 3.2 t/ha. Sekondari variety was mostly preferred in Missungwi (63.1%) while Polista variety was mostly preferred in both Meatu and Sengerema districts (60.3 and 58.9%) respectively. Reasons for preference were high dry matter content, good flavour and sweetness. Polista was highly preferred regardless of its low productivity. The results also show that the consumption of sweet potato in the Lake zone was very high, where 63.1 and 76.2% of farmers in Missungwi and Meatu respectively consumed sweet potato every day, while 63.7% in Sengerema consume sweet potato 3-5 times per week. It was observed that 69.2 and 63.7% of farmers in Missungwi and Sengerema respectively cook sweet potato by boiling whereas 51.5% of farmers in Meatu use both boiling and roasting methods. Nutrient content of fresh sweet potato varied significantly (P≤0.05) with varieties. Moisture content ranged from 55.00 to 72.44%, dry matter 27.56 to 45.00 %, total carbohydrate 23.55 to 41.09 g/100 g, total carotenoid 88.31 to 1620.07 μg/100 g and crude protein ranged from 1.39 to 2.77 g/100 g. Processing had no significant effect (P≤0.05) on ash, crude protein, total carbohydrate, calcium and zinc, while significant effect was observed in reducing sugars, iron, magnesium, phosphorous and total carotenoids. Losses in total carotenoids ranged from 37.72 to 69.13%. Traditional processing caused higher losses of more than 50% in alliii varieties. The main sweet potato varieties found in the market was white-fleshed (33.3%) and cream fleshed (66.7%). Market studies indicated that prices were low in the main season when the quality was good and higher in the low season when the quality was low. Problems experienced by traders were lack of capital, poor marketing, short shelf life, transportation and price fluctuations due to seasons. It is recommended that relevant stakeholders should give priority on post-harvest issues like more diversification of utilization methods, and marketing of sweet potato in the country in order to reduce losses and increase the value of the crop. In addition the breeding programme should put more emphasis on the culinary qualities as well as β-carotene content.
Nutritional status and growth pattern of HIV positive children receiving and not-receiving antiretroviral treatment in Dar es Salaam, Tanzania
(Sokoine University of Agriculture, 2009) Kamuzora, Kokuletage
This study was undertaken to assess the nutritional status and growth pattern of HIV positive children receiving and not-receiving anti- retroviral treatment in Dar es salaam. Specific objectives to assess the nutritional status and growth pattern of children receiving and not receiving ARV treatment. Anthropometric measurements were taken which were height and weight. Biomarkers of HIV i.e. CD4 count were taken at baseline and at the end of the study. The study revealed that HIV positive children receiving ARV were growing slightly better (p > 0.05) in WAZ, HAZ and WHZ than their counterparts not receiving ARV. The study further revealed that, HIV + children who were receiving ARVs had slightly higher (p > 0.05) CD4 and CD4:CD8 ratio compared to their peers not receiving ARVs. It showed that ARVs had small effect on growth of both boys and girls who were taking ARVs and multivitamin combinations. HIV+ children receiving not receiving ARVs followed similar patterns of growth, although the children receiving ARVs had slightly higher z-scores of weight for age and weight for height. HIV infection is a strong risk factor for mortality among children in Tanzania. It was concluded from this study that, although ARVs appeared to have beneficial effect on weight gain, the effect was insignificant. Since all children were receiving multivitamin supplementation, a good nutrition would produce the same effect even if ARVs are not provided. Provision of good nutrition, including supplementation with multivitamin and minerals in a viable, safe and practical approach in the management of HIV+ children. Due to side effects associated with the use of ARVs which are nevertheless designed for adults use of dietary approach is highly recommended for the HIV+ children. This study showed that, use of dietary approach is just as good as using ARVs.
Factors influencing nutrition and food insecurity in Kiroka village
(Sokoine Universitry of Agriculture, 2009) Nkubambela, D.E
Nutritional status in children is an indicator of health and well-being at both the individual and the population level. Malnutrition rates and incidences are still high in Kiroka village. The aim of the study was to identify causes of recurrence of malnutrition among children below five years of age in Kiroka village in Rural Morogoro, Tanzania. Face-to-face interviews with the sampled mothers were conducted using a semi-structured questionnaire. Anthropometric data were collected using standard procedures and analysed using Emergency Nutrition Assessment by SMART program where Z-scores were generated and imported into the SPSS software programme for further analysis. Anthropometric indicators of weight-for-age, weight-for-height and height-for-age indices were employed to assess the nutritional status of children below five years of age. The prevalence rates of stunting, underweight, wasting, and morbidity were 43%, 13%, 3%, and 87%, respectively. Prevalence of underweight of children reported in Kiroka village increased between 2005 and 2007 from 19% to 22% respectively. Nutritional status of children is affected by both inadequate and quality of food, improper feeding practices, level of education of mother, household size, marital status and disease infections. Generally, children were more susceptible to malnutrition as age increased. An educated mother was less likely to have malnourished children. About 64% of the mothers were able to breastfeed their children within one hour after delivery. However, 85% of the infants in Kiroka village are given pre-lacteal foods such as thin cereal-based porridge and water. Only 3% of infants were exclusively breastfed for six months. About 39% of the children started complementary feeding when they were two weeks old. Duration of food shortage and household size had a negative correlation with weight-for-height z-scores. Community nutrition education andiii mobilization of community members to adopt practices that favour good nutrition of children are recommended.
Effect of moringa oleifera leaf meal inclusion in cassava chip based diets fed to poultry
(Sokoine University of Agriculture, 2009) Olugbemi, Taiye Sunday
A study was conducted to evaluate the effect of Moringa oleifera leaf meal (MOLM) as a feed ingredient in cassava chip (CC) based diets fed to broilers and layers. The broiler experiments consisted of a feeding trial, digestibility trial, carcass analysis, haematological evaluation and sensory evaluation. Seven treatments (T) comprising of a control diet (Tl), T2. T3, T4 (20% C with 0%, 5%, 10% MOLM) and T5. T6. T7 (30% C with 0%. 5%. 10% MOLM) were fed to 378 broiler chicks. A reduction in performance was observed with increasing inclusion level of MOLM beyond 5%. Birds on T3 did not differ significantly (P>0.05) in terms of weight gain (46.20 - 49.56g/day), feed conversion ratio (2.57 - 2.84), final body weight (2365- 2569g), feed intake (127.9 - 130.4g) and feed cost per kilogram weight gain (501.4 - 555.0 TSH) from those on Tl, T2 and T5 diets. Digestibility results had to be discarded due to their unreliability. Dietary treatments significantly (P<0.05) affected live weight, carcass weight, dressing percentage, abdominal fat and bone percentages though T3 did not differ (P>0.05) from Tl, T2 and T5. Lean, heart, liver and gizzard percentages differed insignificantly (P>0.05). Haematological parameters were generally not influenced (P>0.05) by treatment except for white blood cells. Addition of MOLM improved meat acceptability. The layer experiments consisted of 80 birds randomly assigned to four diets consisting of a control (TL1) diet containing neither CC nor MOLM and MOLM at 0%, 5% and 10% in combination with 20% C (TL2, TL3, TL4). Feed intake, feed conversion ratio, albumen and yolk percentage were not significantly (P>0.05) influenced by the inclusion of MOLM. The highest (P<0.05) egg weight and Roche colour score were obtained from non control groups with 63.31g from TL3 and 7.79 from TL4 respectively. Feed cost per kilogram (190.6-214.8TSH) and feed cost per kilogram egg (536.3-588.7TSH) significantly declined (P<0.05) with inclusion of MOLM. Addition of 10% MOLM in combination with 20% CC resulted in a 21.96% and 12.06% decline in scrum and yolk cholesterol levels respectively. General acceptability of the cooked eggs was highest from TL4 group. Results of these investigations indicate that broilers and layers can be safely fed MOLM up to levels of 5% and 10% respectively in cassava based diets without deleterious effects. provided CC docs not exceed 20%. Cassava in the form of chips is a good form of poultry feeding and the inclusion of MOLM enhances both meat and egg products by producing carcasses with reduced abdominal fat, improving meat acceptability and egg qualities due to its enhanced yolk colour, reduced cholesterol and cost of producing eggs.
Effects of compliance with food safety standards on costs, benefits and organization of Nile Perch Export Supply Chain in Tanzania
(Sokoine University of Agriculture, 2010) Mpenda, Z. T.
Trading in high-value agro-food and fishery products like Nile perch represents one of the main possibilities for reducing poverty in Tanzania. Nile perch earner foreign exchange and provides employment to communities around Lake Victoria. However, Tanzania has experienced challenges in maintaining and expanding her share of global markets given stringent food-safety requirements in the European Union (EU). Following the three EU Nile perch export bans in the 1990s, several efforts have been made to conform to EU food safety standards in the Nile perch supply chain. This study it analysed levels of conformity to standards, costs and benefits associated with compliance with food safety standards at various stages along the chain; and their effects on the organization of Nile perch supply chain. Secondary data were obtained from different sources including the Fisheries Department of the Ministry of Livestock Development and Fisheries and fish processing plants. Primary data were collected from 239 Nile perch chain actors including processors, traders, boat owners and fishers. The data were analysed using accounting method and categorical logit regression model. Despite inadequate finance and human capacity constraints, the Nile perch industry conformed successfully to HACCP, ISO 9000, ISO 22000 and BRC standards to access to EU market. Compliance was found to be higher at processing stage of the chain than fishing stage. It was associated with high costs depending on the existing quality standards, availability of required equipment, understanding of compliance requirements and common practices in the industry. The benefits associated with compliance accruing to the different actors in the chain and nation exports were higher than the associated costs. Several changes occurred in the organization and governance of the Nile perch supply chain since late 1990s when compliance with food safety standards started. However, these changes could not only be attributed to compliance with the standards. Decline in fish stock also contributed to the observed changes. Notable changes were greater investments, increased fishing efforts and contractual agreements emergence between actors in the supply chain. Results of the logit model suggested that business location, scale of investments, negotiation power and extent of integration along the chain were main factors influencing changes in the Nile perch vertical structure. The government needs proactively to sustain compliance with standards and fishery resources by strengthening Beach Management Units (BMUs), regulations enforcement, food safety standards training and improving actors‟ access to financial services.

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