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Item Mechanisms of mechanical oil expression from rapeseed and cashew.(University College Dublin, 1979-02) Mrema, Geoffrey C.The conventional theory of oil expression from vegetable oilseeds suggests that before substantial oil expression can occur, the oilseed cellwalls have to be ruptured by a combination of physical (crushing) and thermal (cooking) pre-treatments. Results from oil expression tests using rapeseed and cashew on the Instron Universal Testing Machine have suggested an alternative mechanism in which up to 80% oil is expressed through a porous cellular microstructure under pressure without cellwall rupture and at ambient temperature. The porous mission electron microscopy. The cellwall pores (plasmodesmata) were of diameter 0.87 and 0.126 pm wall surface area for rapeseed and cashew respectively. The oil expression process has been successfully described by a mathematical model based on three modified form of Terr.aghi's equation for the consolidation of saturated soils., to describe the behaviour of the consolidating oilseed cakej the Hagen Poiseulle equation for flow of fluids to describe the flow of oil through the pores on the cellwall; and The model has Darcy 's law of flow of fluids through porous media to describe the flow of oil through the intra-kernel voids. in pipes, fundamental equations: a oil expression can occur, the oilseed cellwalls and average porosity of 0.093 and 0.171% of the cellnature of the cellwalls has been confirmed by trans been succeafully applied to experimental data which has revealed that the flow of oil across cellwalls in the seed kernel was the rate determining step. In addition the model was also used to analyse the performance of hydraulic and screw expellers. The study has suggested that the design of both hydraulic and screw expellers could be improved by incorporating an undrained compression pretreatment to rupture cellwalls 3 and by reducing the drainage area to 0.5% - 1.5%. Furthermore^ improved strategies for oil expression have been suggested in two cases, (a) For mechanical expression followed by solvent extraction it is proposed that the physical (pre-crushing) and thermal (cooking) pre-treatments be replaced by an undrained compression pre-treatment. are not r equired (b) where mechanical expression is the sole process^ the pre-crushing pre-treatment should replaced by an undrained compression pre-treatment.Item Modelling the water balance of a small catchment: a case study of Muhu catchment in Southern highlands of Tanzania(Sokoine University of Agriculture, 2000) T. Shiba, Sipho Simeon S.I'he water balance ol'Muhu catchment located in the Southern Highlands of Tanzania in Iringa region was modelled by establishing the empirical relations that exist between storage parameters, rainfall parameters and runoff components. Storage parameters included soil moisture storage and interception. Rainfall parameters included rainfall amount, intensity, duration. throughfalL stemflow and evaporation. Runoff components included total runoff, direct runoff and base How. The catchment's physical and hydrological characteristics that affect these parameters were determined. 1 he assessment of hydrological and physical properties showed that the soils were predominantly sandy clay, having high organic matter content, with a moderately rapid hydraulic conductivity (Ks) of 4.2 cm/h and infiltration rale of 3.8 cm/ h. The bulk density was generally low with an average of 0.9 g/cnT for 0-15 cm depth: 1.1 Ig/cm5 for 15-30 cm depth and 1.30 g/cm’ for 30 - 45 cm depth. The catchment had a slope steepness of 35 % and a varying vegetal percentage cover of about 56 %. The 1997/98 waler year was exceptional with high rainfall (1934 mm) mainly due to the El-nino phenomenon. Sixty-seven percent of the rainfall received in the catchment penetrated the canopy to reach the forest floor as throughfalL On average 3.3 % of the rainfall reached the forest floor as stem flow' while 25.5% of the rainfall was intercepted by the canopy. ThroughfalL stemflow and interception were linearlyIll related to rainfall. Die regression coefficients of all the relationships were significantly different from zero al 1% level (fteO). With increasing percentage surface cover, interception increased while throughfall decreased. The storage capacity of the forest cover was estimated to be 0.7 mm. Il has been found in this study that stream flow and runoff have gradually been increasing since the 1994/95 season. However the rainfall trend docs not support this development. A consideration of runoff curve numbers showed that the observed trend was partly due to catchment degradation, farming activities in the area have gradually been substituting the forest with arable land, thus reducing surface cover. Records indicated that the lowest recorded daily mean How was 0.27 m'/s. while the highest was 1.6 m'/s. I he water balance was positive during the first five months of the wet season. The highest water balance was in April. During this period there was more recharge to the soil moisture and ground water storage. Water balance was negative in the remaining seven months of the water year, with the lowest in September. The developed direct runoff model and water balance model were found to be valid and useful in estimating the respective parameters in forested catchments of the southern highlands of Tanzania.Item Performance evaluation of an indigenous irrigation system at towero village, western Uluguru mountains, Tanzania(Sokoine University of Agriculture, 2000) Kongola, Malongo John MussaIndigenous irrigation methods in mountainous areas are a result of people’s efforts to survive on limited land resource bases. The adoption of an irrigation method depends on whether it does not affect the soil. While surface methods are common in the Uluguru Mountains, drag hose sprinkling is receiving wide use at Towero. Drag hose sprinkler irrigation refers to the local use of sprinklers where water pressure is obtained by gravity flow. Effects of indigenous irrigation systems’ practices on soil erosion were evaluated using field data and aerial photographs. Field data were obtained from six slopes, ranging from 6 to 84%. Two versions of aerial photographs were used to produce land-use maps for 1964 and 1992, respectively. Traversing produced the land-use map of 1999. Land-use analysis revealed that between 1964 and 1999, the area under indigenous irrigation increased by 0.81 ha/ycar. Between 1964 and 1999 the settlement area increased by 0.83 ha/year. Deforestation rate was 6.48 ha/year. Mean crop yields for leeks ranged between 9.65 — 13.53 tonne/ha. Mean specific yields ranged between 0.65 - 1.09 kg/m3. Mean water conveyance, application and storage efficiencies were 83.72%, 86.20% and 99.64%, respectively. All fields wereii over-irrigated based on soil moisture data which were taken daily. Over-irrigation caused inequitable water distribution. Daily sediment load transport in canals A, B and C were 22.2 kg, 187.6 kg and 54.7 kg, respectively. Total sediment loss was 264.6 kg per day. Net downslope splash loss at 84, 70, 65, 24 and 15% slope was 28.9, 19.1, 12.0, 6.0, and 1.0 kg/ha, respectively. The effects of indigenous irrigation systems’ practices at Towero were: soil loss in the form of splash erosion and sediment load transport, and acceleration of deforestation in pursuit for more agricultural land. Hence, efforts to promote soil conservation practices at Towero are essential.Item Repair costs of tractors and comparison of mechanization strategies under Tanzanian conditions(University of Munich, 2000-08) Mpanduji, Sylvester MichaelItem Socio-economic assessment of agricultural commercialisation of indigeneous african vegetables: a case study of african eggplant in Arumeru district(Sokoine University of Agriculture, 2008) Kalugira E. GA study aimed at assessing the socio-economic impact of household’s participation in commercialization African eggplant (solarium aethiopicum) was carried out in four villages in Arumeru district in Tanzania. The study determined the existing extent of commercialization of African eggplant by households, determined and compared at different levels of commercialization the household members’ time allocation, income levels and ownership by gender, as well as land resource allocation for different crops. Data were collected by structured questionnaire for individual farmers supplemented by interview checklists for focus group. SPSS computer programme was used for data analysis. The results showed that: African eggplant growers had significantly higher extents commercialization than non growers. Time spent by household’s members, income levels and women’s control of income was also higher in African eggplant growers. The average land allocation for food crops was 0.76 hectares and 0.70 hectares for African eggplant growers and non-growers respectively which is insignificantly different between the two farmers’ categories. Time in hours per day spent by family members for African eggplant growers was 7.64 while for non-growers was 5.2. Moreover, total annual income in Tanzanian shillings (TShs) of African eggplant growers was 2 449 617 compared to 2 030 767 for non-growers. In case of women’s control of income, there was a slight difference between the two categories in which for African eggplant growers decision making by both husband and wife was higher. The following policy implications have been raised: Commercialization of African eggplant should be enhanced notably through improving technologies. Participation of women should be safeguarded by increased access of women to credit for the short term financing of cash crop productive inputs. Acquiring land for production of African eggplant through renting instead of using land which has been used for production of food crops should be maintained.Item Root-zone soil moisture redistribution in cropping systems under freeze-thaw conditions(University of Manitoba, 2008) Kahimba, Frederick CassianThe availability and distribution of soil moisture within the root zone is a key factor in ensuring better crop growth performance and attaining improved yield. The soil moisture is influenced by farm management practices such as cover cropping that affect the freeze-thaw processes during the fall. This in turn may influence accumulation and redistribution of soil moisture during the winter, and thereafter, the soil’s response to thawing during spring, and availability of soil moisture for the subsequent season. The impact of cover cropping systems on soil temperature, infiltration, and soil moisture redistribution due to soil freezing and thawing was investigated. In addition, the effect of cover crop on the within-season and subsequent-season crop performance and yield was also investigated. Time Domain Reflectometry (TDR) and Neutron Scattering (NS) methods were used to measure the unfrozen and total water contents, respectively. Soil temperature was measured using thermocouples embedded in the soil profile. Soil moisture and soil temperature data were collected from August 2005 to September 2007. Laboratory calibration of the TDR miniprobes indicated the maximum cable length for the RG-58 50 Q coaxial cable to be 40.0 m when 35 mm TDR miniprobes were used. Since the TDR was found to overestimate the liquid water content at soil temperatures below 25°C, a method to correct the field measured TDR soil moisture for temperature effects was developed. During soil freeze-up, water from unfrozen soil layers below the freeze front migrated towards frozen layers above. Compared to non-cover crop treatment, the cover crop treatment did not freeze earlier during the fall, froze to a shallower depth during the iItem Detection of proteolysis in milk by four selected methods(The University of Reading, 2009) Chove, Lucy MlipanoSensitive methods that are currently used to monitor proteolysis are limited due to their high cost and lack of standardisation for quality assurance in the various dairy laboratories. In this study, four methods, trinitrobenzene sulphonic acid (TNBS), reverse phase high pressure liquid chromatography (RP-HPLC), gel electrophoresis and fluorescamine, were selected to determine their suitability for the detection of proteolysis in milk by added trypsin, plasmin, Pseudomonas fluorescens NCIMB 701274 (414) and Pseudomonas fluorescens NCIMB 702085 (416) and Bacillus licheniformis enzymes. Raw, pasteurised and UHT milk used to study proteolysis were analysed by the four methods. Pseudomonas fluorescens enzyme was extracted in this study since commercial enzymes are not available. All four methods confirmed that Pseudomonas fluorescens 416 was more proteolytic than Pseudomonas fluorescens 414. Dialysis was effective in the purification of Pseudomonas fluorescens (Ps. fl.) enzymes increasing the detection limit for the fluorescamine method, which had a low upper detection limit. Prominent peaks by RP-HPLC were shown to occur between 20-30 min for Pseudomonas fluorescens but 20-25 min for Bacillus licheniformis. RP-HPLC confirmed a peptide peak at 35 min in pH 4.6 soluble extract, which was absent in 6% TCA soluble extract, was from plasmin. Casein breakdown profiles by gel electrophoresis confirmed preference for 0-casein degradation over a and K-caseins by both Ps. fl. and B. licheniformis. Comparison of raw and pasteurised milk (72, 85 and 90°C for 15 s) revealed that pasteurisation was insufficient to inactivate plasmin inhibitors. The pH 4.6 and 6% TCA soluble extracts of UHT skim milk with added trypsin or plasmin showed high correlations (R2 > 0.93) by the TNBS, fluorescamine and RP-HPLC methods, confirming increased proteolysis during storage. Gel electrophoresis showed that breakdown products from trypsin were similar to plasmin although the former caused more extensive proteolysis than the latter due to higher enzyme activity, y-caseins, formed as a result of P-casein degradation disappeared (1484 and 742 BAEE units of added trypsin on days 3 and 7) due to extensive proteolysis. This finding had not previously been reported. Milk processed at high temperatures (110, 120, 130 and 142°C for 2 s) had lower proteolytic activities than raw milk and milk heated at 85°C implying inactivation of plasmin at temperatures of 110°C and above. This was observed in all the methods assessed. The TNBS method was recommended on the basis of its accuracy, reliability, simplicity and cost.Item Detection of proteolysis in high temperatures treated milk by reverse phase high performance liquid chromatography (RP-HPLC)(Academic Journals, 2014-02) Chove Lucy M.; Grandison S. Alistair; Lewis Michael J.; Issa- Zacharia AbdulsudiProteolysis of UHT milk during storage is one of the problems affecting the dairy industry worldwide. Native enzymes have been implicated as being the main cause of spoilage of such milk. In the current study, reverse phase high pressure chromatography (RP-HPLC) method was used to detect proteolysis by native enzymes in high temperature heated milk. The aim of this research was to assess susceptibility of milk to proteolysis by native enzymes, after being subjected to various temperature- time processing conditions. Samples of raw and heated milk were clarified prior to analysis. Clarification was carried out to obtain pH 4.6 and 6% TCA soluble extracts, which were injected into RP- HPLC after filtration. This method confirmed that raw milk and milk processed at 85°C /15 s were the most proteolysed, indicating that the high temperatures employed during this study (110, 120, 130 and 142°C for 2s) inactivated the native enzymes. The RP-HPLC method is a useful method for the detection of proteolysis in milk.Item Status assessment and roadmap for improvement of food safety management systems in Africa: the case of Tanzania(Ghent University, 2015) Kussaga, Jamal BakariChapter 1 reviews various literature sources to provide an overview of the characteristics of food production sectors and the legal framework for food safety in Tanzania and tools used to measure performance of food safety management systems in the food industry'. It was found that Tanzania’s economy depends on agriculture: the manufacturing sector being largely agro-based and composed of micro- and small-scale enterprises. Majority of the food companies target the domestic market, especially, the dairy sector, while a few sectors like fish and horticulture produce for the export market, The current food laws and regulations are not yet adequate and well enforced to provide maximum protection to consumers. Besides, there is no national food safely policy as yet. Several institutions are involved in the food control without proper coordination and harmonisation of responsibilities. Furthermore, application of best practices and hazard analysis critical control point principles is not mandatory to food sectors serving the domestic market, limiting their use. This situation could contribute to food safety problems (including microbiological and chemical contamination and foodbome diseases) along the local and export food-value chains. Lastly, the chapter highlights also on the scientific tools, the food safety management system-diagnostic instrument and microbiological assessment scheme, developed by various researchers which were further used in this study. Chapter 2 provides a broad overview of the deficiencies and opportunities for improvement of food safety management systems of the African food industry-. Several literature sources were consulted to provide insights in food safety status of African food products, deficiencies of current food safety management systems, hurdles due to context characteristics and possible improvement strategies. Literature on microbiological and chemical safety of various products including fruits and vegetables, fish, meat, dairy and cereals were analysed to get insights in the current safety status of African food products. It was found that microbiological and chemical contamination exceeded the legal limits in most of the products targeted for export and local markets in the reviewed reports. Analysis of the deficiencies of food safety management systems in the reviewed reports revealed that the majority of core control and assurance activities were not yet developed, whereas for the ones developed (i.e. export oriented and large-scale companies), many were at basic level. The hurdles due to context characteristics in the reviewed reports were observed at government (due to poor legal framework for food safety), sector/branch organisations (lack of sector organisations and guidelines), market/rctail (inadequate food safety demands), and company levels (poor workforce quality, high dependency on chain actors, stakeholders’ conflicting demands) which affect performance of food safely management system in Africa. Lastly, measures for improvement were proposed at government (strengthen the national legal framework for food safety, formation of accreditation bodies and food safety education at all levels):sector/branch organisations (formation of sector guidelines and recommended use of traceability systems and auditable standards), inarkct/retail (private certification and price premiums, and expertise support) and company levels (technological innovations in hygienic design of equipment and facilities, set-up assurance activities, and creating supportive administrative structures). These measures were used as inputs for the development of generic roadmap for improvement of ESMS in Tanzanian food industry. Chapter 3 applied the food safety management system-diagnostic instrument to analyse the set-up and operation of food safety management system (control and assurance) activities in view of system output and context riskiness in 22 dairy processing companies in Tanzania. I lierarchical cluster analysis with the furthest neighbour and squared Euclidean method was used to analyse data; then, Kruskal Wallis Non Parametric test was applied to determine the significant differences among the clusters. Three clusters of companies di Hering in levels of set-up and operation of the ESMS and system output, but all operated in a similar moderate-risk context were identified. Cluster IA and IB had moderate system output, whereas cluster II had poor-moderate level. The microbiological assessment scheme was applied in one company to get deeper insight on the actual microbiological safety output of the current systems of dairy' processing companies. Six indicator micro-organisms for faecal hygiene {Escherichia coli), personal hygiene {Staphylococcus aureus), pathogens {Listeria monocytogenes. Salmonella spp.) and general process hygiene {Enterobacteriaceae and total viable counts) were analysed in nine critical sampling locations along the cultured milk production line. The actual microbiological assessment indicated contamination of products, food contact surfaces, and hands of the personnel with indicator microorganisms of faecal hygiene {Escherichia coli), personal hygiene {Staphylococcus aureus), and pathogens {Listeria monocytogenes) beyond the set limits. A two-stage intervention approach was proposed to enable commitment and sustainable improvement on the longer term. In the first stage, less demanding interventions (in terms of expertise/technology, financial and human resources) were recommended, whereas, high demanding measures (expensive and time consuming) were suggested in the second stage. Similarly, these interventions were used to develop the generic roadmap for improvement of food safety management systems in Tanzanian food industry. Chapter 4 assesses the food safety management system output in view of the current design and operation of food safety management system activities and context riskiness of these systems in order to identify the opportunities for improvement of the risk-based food safety management systems in the fishery sector. The diagnostic instrument was applied to assess the design and operation of core control and assurance activities in view of context riskiness and system output in 14 fish processing companies in Tanzania. Hierarchical cluster analysis with the furthest neighbour and squared Euclidean method revealed 2 clusters (cluster I and II) differing in system output but with similar level of food safety management systems (average level) and context riskiness (moderate-risk). In overall, cluster I companies had good system output while cluster II had moderate to good output. However, majority of the fish companies needed improvement of their FSMS to higher levels and reduce the context riskiness to assure good system output. A two-phase intervention approach was also proposed to implement the suggested measures in the fish companies. The less expensive interventions (like sanitation procedures, recruitment of skilled personnel on permanent basis) that can be implemented in the short- term are recommended for phase I. More expensive interventions (such as setting-up assurance activities, hygienic design of equipment and facilities, automation of the production process and sanitation) to be adopted in the longterm are proposed for phase II. These measures were also used as inputs to develop the generic roadmap for improvement of food safety management systems in Tanzanian food industry. Chapter 5 describes a combined assessment by the diagnostic instalment and microbiological assessment scheme to assess microbiological safety output of a risk-based food safely management system of a fish exporting company. The food safety management system diagnosis indicated average food safety management system activities which operated in moderate-risk context level but with good system output. The actual microbiological assessment involved 7 microbiological indicators for pathogens {Vibrio cholerae. Listeria monocytogenes and Salmonella spp.), faecal hygiene {Escherichia coli), personal hygiene {Staphylococcus aureus), and general process hygiene {Enterobacteriaceae and total viable counts) analysed in 12 critical sampling locations along the frozen Nile perch fillets processing line. Enterobacteriaceae and total viable counts exceeded regulatory limits in raw materials and working tables, whereas Staphylococcus aureus on operator's hands were beyond the general microbiological guidelines in the fish industry. Among the intervention measures for improvement included hygienic design, specific produclion/sanitation procedures and independent validation, process automation and change in personnel recruitment criteria. Likewise, the proposed measures were used to develop roadmap for improvement in the Tanzanian food industry. Chapter 6 involves a comparative assessment of the design and operation of food safety management system activities between the domestic oriented companies (dairy sector) and export oriented companies (fishery sector). The food safety management system-diagnosis data from Chapter 3 (dairy' sector) and Chapter 4 (fishery' sector) were evaluated to identify possible causes in the differences in the systems performance between the two sectors. Fish companies had average food safety management system and medium-good system output, while dairy' companies indicated basic-average food safety management systems and moderate system output. However, the food safety management systems of both sectors operated in moderate-risk context. This illustrates that both sectors need specific measures to improve their food safety management systems and reduce the risk-level of the context to guarantee food safely. The measures to reduce the level of context riskiness included putting high and specific requirements on operators’ competence level, describing all activities in standard operating procedures, and setting requirements on product use by major customers. The measures on the design and operation of food safely management systems involve use of industrial cooling facilities, hygienic design, strict raw material control, specific sanitation programmes, and analysis of critical control point. Dairy' companies need to set-up assurance activities including validation, verification, documentation, and record-keeping system. Enabling regulatory' environment (like national food safety policy, proper enforcement of laws and regulations) has to be established for the entire food industry (including the domestic market oriented sectors), to improve the design and operation of current core control and assurance activities and guarantee food safely. improvement technological infrastructure The measures to reduce the level of context riskiness included putting high and specific requirements on operators’ competence level, describing all activities in standard operating procedures, and setting requirements on product use by major customers. The measures on the design and operation of food safely management systems involve use of industrial cooling facilities, hygienic design, strict raw material control, specific sanitation programmes, and analysis of critical control point. Dairy' companies need to set-up assurance activities including validation, verification, documentation, and record-keeping system. Enabling regulatory' environment (like national food safety policy, proper enforcement of laws and regulations) has to be established for the entire food industry (including the domestic market oriented sectors), to improve the design and operation of current core control and assurance activities and guarantee food safely. Chapter 7 brings about the general discussion, roadmap for improvement of food safety management systems in the Tanzanian food industry', conclusions and recommendations for further research. Two concepts, the food quality relationship model and the improvement cycle were used to design the roadmap. The food quality relationship describes food quality as a function of food behaviour and human behaviour, food behaviour is dependent on dynamic product properties (food dynamics) and the applied technological conditions to stabilise the properties. Human behaviour is dependent of the dynamic individual decision-making of employees (human dynamics) and the applied administrative conditions to direct this behaviour (setting procedures and working practices in place). The improvement cycle involves three steps: (1) mapping the problem area (collecting information about the problem and documentation), (2) analysing the problem area (identification of causes and effects), and (3) redesigning (development and implementation of solutions). Based on the food quality relationship model, three levels of increasing efforts were defined; 1) changes in product and people behaviour, 2) changes in process conditions and administrative conditions, and 3) changes in the technological and organisational arrangements. Fish and dairy’ processing companies could use the generic roadmap to derive their company specific roadmaps towards more effective food safety management systems. Although this study was exclusively conducted in fish and dairy' sectors, the proposed generic measures for improvement could be also used by other food production sectors. However analysis of other sectors like fruits and vegetables, meat and poultry', and hospitality industry would identify specific deficiencies in their food safety management systems and tailor-made measures for each sector could be proposed to ensure supply of safe products for the entire nation. Moreover, this study focused on the techno-managerial approach of food safely management systems, however, the human factor, the so called ‘food safety climate or culture* could have an important role in the final performance of a food company. Therefore, future studies could take into consideration the food safety climate factor.Item Effect of solar drying methods on total phenolic contents and antioxidant activity of commonly consumed fruits and vegetable (mango, banana, pineapple and tomato) in Tanzania(Academic Journals, 2015-05) Mongi, Richard J.; Ndabikunze, Bernadette K.; Wicklund, Trude; Chove, Lucy M.; Chove, Bernard E.The effects of solar drying methods [Cabinet direct (CDD), cabinet mixed mode (CMD) and tunnel (TD) drying] on total phenolic content (TPC) and antioxidant capacities of commonly consumed fruits and vegetable in Tanzania were investigated. The TPC and FRAP in mangoes (Mangifera indica cv. Dodo, Viringe and Kent), bananas (Musa acuminata, cv. Kisukari, Kimalindi and Mtwike), pineapples (Ananas comosuss cv Smooth cayenne) and tomatoes (Lycopersicum esculentum cv. Tanya, Cal J and Onyx) were evaluated using Folin-Ciocalteu reagent and ferric reducing antioxidant power (FRAP) methods, respectively. There were significant (p<0.05) variations in TPC (mg GAE/100 g DM) and FRAP (μmol/100 g DM) among the fresh fruit and vegetable samples. The highest TPC was in tomato (476.6±8.6 - 538.9± 1.4) and lowest in banana (139.3±2.3 - 189.2±2.7). Drying methods had significant (p<0.05) effect on TPC and antioxidant values of the samples. All fresh samples had higher TPC levels but declined significantly in dried samples with the exception of tunnel dried tomatoes. Among the dried samples, the tunnel dried samples had less TPC loss (6-16%) than the cabinet dried samples (17-42%). The cabinet direct and mixed mode samples were not statistically different (p>0.05) from each other. However, tunnel dried samples had less FRAP loss (6-13%) which were statistically different (p<0.05) from the cabinet dried samples (14-56%). Percentage TPC and FRAP recoveries (%) differed significantly (P<0.05) between the varieties within the fruits/vegetable for both drying methods. A strong 2 2 correlations between TPC and FRAP in both fresh (R = 0.970) and dried samples (R =0.8636) suggests that solar drying methods have significant effects on total phenolic contents and antioxidant activities of fruits and vegetables with tunnel drying method giving significantly less effects.Item Nutritional quality and functional properties of baobab (Adansonia digitata) pulp from Tanzania(Canadian Center of Science and Education, 2016) Aluko, Angela; Kinyuru, John; Chove, Lucy Mlipano; Kahenya, Peter; Owino, WillisBaobab (Adansonia digitata L.) is a majestic tree associated with human habitation in some of the semi-arid regions of Africa and establishes an enormous economic and nutritional importance to the rural residential districts. The fruit pulp is considered to be of high nutritional significance; particularly vitamin C and calcium, also possess antioxidant functions as well as high dietary fiber content. Although it is a potential fruit for improving local diets and livelihoods,this fruit is underutilized and its potential not yet fully acknowledged. This work was contracted with the aim of defining the nutritional quality and functional properties of baobab pulp harvested from some selected parts of Tanzania. Results indicated that the pulp from the three locations had moisture content which ranged between 9.16% to 10.30%, fat 0.46%-1.98%, ash 4.75%-5.21%, fiber 5.91%-9.65%, protein 3.23%-3.53%, carbohydrate 80.49%-85.19, vitamin C 169.74mg/100g-231.57mg/100g, beta-carotene 2.16 mg/100g-3.19mg/100g.Fructose 0.56±0.15-0.81±0.17g/100g, glucose 0.77±0.26-0.87±0.31g/100g and sucrose 0.75±0.25-0.84±0.29g/100g. The substantial differences (p≤ 0.05) between locations were observed in fat, crude fiber, carbohydrates, and fructose. Vitamin C, beta-carotene, protein, ash, moisture, sucrose and glucose showed no significance difference (p≤ 0.05) among locations. The functional properties included emulsification, foaming and gelling properties which ranged between 37.9-45.15%, 1.85-6.57% and 11-12% respectively and were significantly different (p≤ 0.05) among locations. The results show that baobab pulp has a good content of nutrients and functional properties which can be useful in food industries.Item Influence of botanic and geographic origin on quality of honey from Tanzania.(Sokoine University of Agriculture., 2016) Shekilango, Salama GhuioIn aview of the expanding global market, characterization of floral and geographic origins of honey has become a more important issue than ever. In general, prices of honey at the international market are set according to floral and geographic origin of the nectar, which relate to the chemical composition. This study was conducted to assess and characterize Tanzania honey from different floral origins and geographic zones based on physicochemical properties and minerals content, sugar profile, total phenol and antioxidant activities as well as sensory properties and consumer acceptability. Samples from two floral origins, Miombo and Acacia were collected from five different zones in Tanzania namely Central. Coastal. Lake. Northern and Southern zones and subjected to chemical and sensory analyses. Complete randomized block design with floral origin and geographic zones as main principal factors were used to assess the effect of these factors on stated parameters. Moisture content, ash, pH, acidity, viscosity and colour were determined as per methods described in AOAC (2005). Phenolic content was determined using modified Folin Ciocalteau method and antioxidant activity using Ferric Reducing Antioxidant Power (FRAP) assay. Sugar profile and quantification was performed using Shimadzu high- performance liquid chromatograph equipped with refractive index detector (RID-10A) as per method 977.20 in AOAC (2005). Minerals: copper, zinc, lead, iron, calcium and magnesium were determined using Atomic Absorption Spectophotometer (AAS). sodium and potassium using flame photometer as described by AOAC standard methods (2005). Quantitative Descriptive sensory analysis was done using a panel of 8 trained judges using 9 point an unstructured line scale for rating the intensity of an attribute while consumers acceptability study was done using a 9 point hedonic scale as described by Lawless and iii Heyman (2010) to evaluate acceptability for the attributes of colour, aroma, viscosity and general acceptability. Data were analysed by R software for univariate Analysis of Variances (ANOVA) to determine significant variations between the main factors. Means were separated by Tukey's Honest significant differences at p < 0.05. Multivariate Principal Component Analysis (PCA) was done by Latentix software and Cluster analysis was done by Latentix and R software to determine the systematic variations in the study variables. Most properties of honey varied significantly (p < 0.05) between geographical zones and floral origins with values of honey from Mioinbo floral origin being higher compared to honey samples from Acacia origin. Northern zone honey samples within Mioinbo origin had significantly (p < 0.05) higher moisture content, ash and acidity while Lake zone honey samples had significantly (p < 0.05) higher viscosity. Southern highland Mionibo honey samples had higher colour value on pfund scale. PCA results showed that colour and viscosity had more effect on the variability of physico chemical properties. Phenolic content (mg gallic acid equivalent/100g) and antioxidant activities as pM Fe2‘/100g were significantly (p < 0.05) higher in the Northern zone than in other zones. Honey samples from Mioinbo had significantly higher values of 127.9 - 395.2 pM Fe2+/100g than Kcacia honey samples with values of 119.5 - 168.8 pM Fe27100g between floral origins. Bi plot from principal component analysis, PCI explained 99.2% of variations and showed that both parameters (total phenol and antioxidant activity) had higher effect on the variability. A strong correlation (R2 = 0.929 and R2 = 0.869) between phenolic contents and antioxidant activities were observed in both Mioinbo and Acacia honey samples. respectively. iv There were significant differences (p < 0.05) in fructose, sucrose and total sugars between zones and floral origins. Fructose was found to be the most dominant sugar in the honey samples in each zone and floral origin with the highest contents observed in Acacia honey samples (44.7 - 47.0 g/lOOg) than their Miombo counterpart (39.5 - 42.0 g/lOOg). Glucose, the second dominant sugar was not significantly (p > 0.05) different between floral origins and among zones. Sucrose occurred in small amounts in honey samples from all zones and floral origins. The variation of each sugar between zones within each origin were also significant (p < 0.05) with Northern zone had the highest content of total sugar. PCI bi plot explained 90.7% of total variations with high contribution from fructose and total sugars. Potassium was observed to be the most abundant macro minerals in the honey samples (380.2 - 3488.1 ppm) followed by magnesium (128.1 - 2409.5 ppm), calcium (86.3 - 336.6 ppm) and sodium (78.1 - 165.3 ppm) while iron was the most abundant micro minerals (24.5 - 36.0 ppm) followed by zinc (2.5 - 8.7 ppm) and copper (0.2 - 0.5 ppm). The northern zone honey samples from both floral origins had lead contents above maximum allowed limits as per Tanzania honey standard. The variations in macro minerals between zones were significant with Northern zone having higher contents of Ca. Mg, K and Na in samples originating from Miombo floral origin. Furthermore, the variations in mineral contents between floral origins were also significant with honey samples from Miombo floral origin having significantly much higher content of minerals than Acacia honey samples. Multivariate cluster analysis revealed grouping/similarities of zones according to the mineral they contain. In quantitative descriptive analysis, variations in mean intensity scores of attributes between zones were significant (p < 0.05) in aroma, clarity, hue, viscosity and whiteness, respectively for honey samples from Miombo origin. Southern zone showed high values in aroma and hue, Central zone had high viscosity values while Coastal zone had highest V values in clarity and whiteness compared to other zones. In sample from Acacia origin. Northern zone had significantly (p < 0.05) highest scores in aroma, viscosity and whiteness where Lake zone had high values in clarity and Central zone had high values in hue. Therefore, the study has revealed that fructose was the most abundant sugar in the honey samples while potassium and iron arc the most abundant macro and micro minerals in honey samples under the study. Furthermore, geographical zones and floral origins have significant influences on physical chemicals properties, total phenols and antioxidant activities sugar, minerals and sensory properties of honey samples from five geographical zones and two floral origins in Tanzania. It is therefore recommended that, honey be included in human diet due to its high nutritional and antioxidant properties. In addition, further research be undertaken to create a data base which will successfully enable characterization of Tanzania honey, thus increasing its competitiveness in the local and international market.viewItem Development and sensory evaluation of yoghurt flavoured with solar dried fruits(Pearl Research Journals, 2017) Ndabikunze, B. K.; Mumba, F. G.; Ngowi, H.; Chove, L; Mongi, R; Abdulsud, I.A study of developing solar dried fruit (5%) flavoured yoghurts using three types of fruits was conducted to determine acceptability and shelf life of developed products. A total of six samples namely banana, mango, pineapple, banana/mango, banana/pineapple and mango/pineapple were used as flavours in yoghurts. They were added either as fruit pieces or as powders. Shelf life projection study suggested that developed yoghurt products could be stored for up to 21 days at 4 °C without undergoing spoilage. Plain yoghourt (control) was the most liked sample and scored highest mean values for all attributes, which was significantly different from all other samples (p<0.05). Among the fruit flavoured yoghourts, mango was the most preferred sample in terms of flavor, aroma and general acceptability whereas the pineapple was the least acceptable. Although yoghurts flavoured with fruits pieces scored higher mean values in all sensory attributes than yoghurts flavoured with powdered fruits, no significant differences (p>0.05) between the two forms of fruit flavours was found. This needs to be further investigated. Thus, although the control was the most liked sample, solar dried fruit can be successfully used as yoghurt flavour, which may improve the texture and nutritional quality of the formulated yoghurts, making them available throughout the year, hence increasing farmer’s income.Item Monitoring proteolysis in milk caused by pseudomonas fluorescens by the TNBS method(Pearl Research Journals, 2017-11) Chove, L. M; Grandison, A.; Lewis, M.The objective of this study was to monitor proteolysis of milk during storage at 20 and 4° C by two strains of Pseudomonas fluorescens namely: NCIMB 702085 (416) and NCIMB 701274 (414) by the TNBS method. Since commercial Pseudomonas fluorescens enzymes are not available, live Pseudomonas fluorescens microorganisms were inoculated into milk followed by extraction and purification by dialysis. Bacterial enzymes obtained were then inoculated into UHT skim milk. Non-inoculated milk was used as a control. Results obtained showed that Pseudomonas fluorescens NCIMB 702085 was more proteolytic than Pseudomonas fluorescens NCIMB 701274. It was concluded that the TNBS method proved useful in monitoring proteolysis in milk by Pseudomonas fluorescens.Item Preliminary study on the role of ionic calcium in gelation and proteolysis of UHT milk(Macrothink Institute, 2017-12-28) Chove, Lucy Mlipano; Lewis, MichaelA study was conducted to determine the influence of ionic calcium on gelation and proteolysis in milk. Raw milk was heated to 142 °C for 2s followed by cooling to 5 °C to make UHT milk. Two sequestering agents, Trisodium citrate (TSC) and Sodium hexametaphosphate (SHMP) were added at 0.04 - 0.08% (w/v) to the processed UHT milk to reduce the ionic calcium levels. Proteolysis and gelation were induced by addition of trypsin (248 BAEE units), 0.03% (v/v) chymosin and 10 6 cfu/mL Pseudomonas fluorescens NCIMB 702085 (Ps. fl. 416) to UHT milk. Samples were stored at 25 °C for 21⁄2 weeks to monitor gelation and Ca 2+ and some were incubated at 37 °C for 2h to monitor proteolysis. SHMP reduced more Ca 2+ than TSC. Ca 2+ reduction was accompanied by an increase in pH, most evident with TSC at 25 °C. Gelation was not observed in samples inoculated with Ps. fl. 416 (with sequestering agents) even after 9 days of storage, suggesting the importance of calcium in gelation. Chymosin treated samples gelled on day 0, whereas other samples gelled after 4 days. Trypsin increased Ca 2+ to levels higher than originally present in control UHT skim milk. Although in the current study, proteolysis was higher in samples inoculated with Pseudomonas fluorescens 416, no clear relationship was established between proteolysis and gelation in UHT milk. This observation implies that proteolytic activity is not influenced by Ca 2+ . However, longer time study using sodium azide to prevent bacterial contamination would be required to confirm these findings.Item Detection of proteolysis in milk by pseudomonas fluorescens using urea PAGE method(Macrothink Institute, 2017-12-28) Chove, Lucy Mlipano; Alistair, Grandison; Michael, LewisProteolysis of milk during storage by two strains of Pseudomonas NCIMB 702085 (414) and NCIMB 701274 (416) was investigated using the Urea PAGE method. Pseudomonas fluorescens enzymes were also extracted and purified by dialysis before inoculation into UHT skim milk in an attempt to partially purify the enzyme. Results showed that dialysis removed some peptides and amino acids which would interfere with the assay procedure. The method also confirmed that Pseudomonas fluorescens NCIMB 701274 (416) was more proteolytic than Pseudomonas NCIMB 702085 (414). Thus, Urea PAGE is a useful method for monitoring proteolysis in milk by Pseudomonas fluorescens.Item Effect of depth and distance of the borehole from the septic tank on the physico-chemical quality of water(Macrothink Institute, 2017-12-28) Chove, Lucy Mlipano; Mongi, Richard; Chenge, LawrenceA study to examine the effect of depth and distance of the boreholes from the septic tank on physico-chemical parameters of the borehole water consumed in Dar Es Salaam, Tanzania was conducted. Samples were collected from 48 boreholes in Ilala, Kinondoni and Temeke districts and subjected to pH, B.O.D (Biological Oxygen Demand), total hardness, copper and lead analyses in relation to safety and quality levels set by WHO and TBS. Analysis by R-statistics indicated that pH and B.O.D significantly (p<0.05) decreased as the depth of borehole increased, whereas total hardness was significantly (p<0.05) higher in very deep boreholes than the other heights. Total hardness and pH were not significantly (p>0.05) affected by distance between septic tank and borehole and the B.O.D levels were significantly higher in the borehole water situated near the septic tank than those which were far. Based on the physico-chemical characteristics of water, 25% of the samples did not comply with WHO and TBS specification limits while 75% complied, most of which had shallow depths and were situated near the septic tank. It may thus be concluded that both the distance and the depth between septic tank and borehole influenced physico-chemical characteristics of water.Item Evaluating the effect of planter downforce and seed vigor on crop emergence and yield in Hill-drop vs Singulated Cotton.(2018 Beltwide Cotton Conferences, San Antonio, 2018-01) Virk, S. S.; Porter, W. M.; Fue, K. G.; Snider, J. L.; Whitaker, J.Selection of correct planting parameters and their optimization based on current field conditions is crucial in achieving high crop emergence, which can translate to higher yields. A study was conducted during 2017 to evaluate the effect of planter downforce and seed vigor on crop emergence and yield in two cotton varieties planted with singulated and hill-drop seed plates. For this study, two cotton varieties (a small seeded low vigor variety and a large seeded high vigor variety) were planted at 1-inch seeding depth using two different planters to obtain singulated and hill-drop planting conditions. Two seeding rates of 29,000 seeds/ac and 42,500 seeds/ac were used to represent a typical low and high population for planting cotton in Georgia. Planter downforce treatments consisting of low, medium and high downforce values (100, 200 and 300 lbs., respectively) were implemented using the available downforce technology on both planters. Field data collection consisted of emergence counts at one and three weeks after planting and yield data from the center two rows of a four row plot at the end of the season. Data analysis indicated that singulated seeds were more effective in low downforce treatments independent of the crop variety. Hill-drop seeds exhibited better crop emergence (75-81%) in higher downforce treatments as compared to crop emergence (62-72%) obtained with singulated seeds. Yield data also suggested that singulated cotton can maximize emergence in low to medium downforce conditions for large seeded high vigor varieties whereas hill-drop cotton yields better with small seeded low vigor varieties planted at medium to high downforce. Results showed that low vigor varieties require higher seeding rates (more seeds per foot) when planted using low downforce to provide an overall high crop emergence rate whereas this trend was not observed in the high vigor variety. A comparison among seeding rates showed that higher seeding rates did not maximize crop emergence when planted as hill-drop. Overall results from this study emphasized the importance of using correct planting parameters (downforce, seeding rate, and variety) based on existing field conditions to maximize crop emergence and yield.Item Real-time 3-D measurement of cotton boll positions using machine vision under field conditions(2018 Beltwide Cotton Conferences, San Antonio, 2018-01) Fue, K. G.; Rains, G. C.; Porter, W. M.; Tifton, G. A.Cotton harvesting is performed by expensive combine harvesters that hinder small to medium-size cotton farmers Advances in robotics provide an opportunity to harvest cotton using small and robust autonomous rovers that can be deployed in the field as an “army” of harvesters. This paradigm shift in cotton harvesting requires high accuracy 3D measurement of the cotton boll position under field conditions. This in-field high throughput phenotyping of cotton boll position includes real-time image acquisition, depth processing, color segmentation, features extraction and determination of cotton boll position. In this study, a 3D camera system was mounted on a research rover at 82° below the horizontal and took 720p images at the rate of 15 frames per second while the rover was moving over 2-rows of potted defoliated cotton plants. The software development kit provided by the camera manufacturer was installed and used to process and provide a disparity map of cotton bolls. The system was installed with the Robot Operating System (ROS) to provide live image frames to client computers wirelessly and in real time. Cotton boll distances from the ground were determined using a 4-step machine vision algorithm (depth processing, color segmentation, feature extraction and frame matching for position determination). The 3D camera used provided distance of the boll from the left lens and algorithms were developed to provide vertical distance from the ground and horizontal distance from the rover. Comparing the cotton boll distance above the ground with manual measurements, the system achieved an average R2 value of 99% with 9 mm RMSE when stationary and 95% with 34 mm RMSE when moving at approximately 0.64 km/h. This level of accuracy is favourable for proceeding to the next step of simultaneous localization and mapping of cotton bolls and robotic harvesting.Item Deep learning based Real-time GPU-accelerated tracking and counting of cotton bolls under field conditions using a moving camera(2018 ASABE Annual International Meeting, 2018-08) Fue, Kadeghe G.; Porter, Wesley; Rains, GlenRobotic harvesting involves navigation and environmental perception as first operations before harvesting of the bolls can commence. Navigation is the distance required for a harvester’s arm to reach the cotton boll while perception is the position of the boll relative to surrounding environment. These two operations give a 3D position of the cotton boll for picking and can only be achieved by detection and tracking of the cotton bolls in real-time. It means detection, tracking and counting of cotton bolls using a moving camera allows the robotic machine to harvest easily. GPU-accelerated deep neural networks were used to train the convolution networks for detection of cotton bolls. It was achieved by using pretrained tiny yolo weights and DarkFlow, a framework which translates YOLOv2 darknet neural networks to TensorFlow. A method to connect tracklets using vectors that are predicted using Lucas-Kanade algorithm and optimized using robust L-estimators and homography transformation is proposed. The system was tested in defoliated cotton plants during the spring of 2018. Using three video treatments, the counting performance accuracy was around 93% with standard deviation 6%. The system average processing speed was 21 fps in desktop computer and 3.9 fps in embedded system. Detection of the system achieved an accuracy and sensitivity of 93% while precision was 99.9% and F1 score was 1. The Tukey’s test showed that the system accuracy and sensitivity was the same when the plants were rearranged. This performance is crucial for real-time robot decisions that also measure yield while harvesting.