Theses and Dissertations Collection

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Quality and quantity of maize and sorghum vegetative parts harvested at different stages of plant growth as fodder for livestock
(Sokoine University of Agriculture, 1994) Eligy J. M. Shirima
Two on-station research experiments were conducted at the Livestock Production and Research Institute, Mpwapwa and one at Pasture Research Center, Kongwa both in Central Tanzania from January to October, 1993. Four treatments in maize, grown in Mpwapwa station, were stripping (SR), topping (TP), stripping + topping (STP) at silking stage and whole plant stover (WPL or control) were assigned randomly within the four blocks of a complete randomized block design experiment. Only SR and WPL treatments were performed in sorghum trials in Kongwa under the same experimental design as in maize but each were replicated twice within each of the four blocks. Also three treatments replicated thrice for measuring the intake and digestibility of the SR, TP and WPL obtained from the maize trial were done at Mpwapwa center by using nine adult BHP male sheep. Complete block design was used by blocking the sheep on weight basis ranging from 29 to 37 kg live weights (mean 32.8 + 1.0). Both animals received equal amount of supplement diet (maize bran + sunflower cake). A village survey through questionnaire and physical body weight measurement of cattle every other fortnight was carried out in Berege village in Dodoma region from the start of the dry season (June) to mid- dry season (October). Sample collection of forage used by the animals was done on the same day after weighing the animals. Ten farmers with improved dairy cattle (Mpwapwa breed) were incorporated. An additional survey was also conducted in Kilimanjaro region among eight farmers to explore the farmer’s knowledge on the use of SR, TP and STP from maize. In maize the highest vegetative biomass production including the final residues after the grain harvest was gained with the STP treatment followed by TP with 5.44 t/ha and 5.35 t/ha respectively (p<0.05). Less fodder materials were collected from WPL (4.23 t/ha) due to field losses. No significant difference were found in sorghum fodder yields despite the leaf losses in WPL. Stripping in sorghum yield 2.2 t/ha and WPL as 1.8 t/ha. In maize total CP accrued from STP were (287 kg/ha) ), TP (234), SR (177) and WPL (138). The IVOMD of the fractions were in the order of 75%, 69%, 64% and 52% in SR, STP, TP and WPL fractions respectively. Seventy-three percent more CP was produced from SR of sorghum than WPL treatment with 123 kg/ha by 71 kg/ha respectively. Digestibility (IVOMD) of the SR leaves from sorghum was 79 % while 55 % from the WPL leaves. The feed intake of SR leaves in maize was more than twice (850 g/day) that of the WPL stover (361 g/day) when fed to sheep. The total digestible crude protein (DCP) from SR of maize was 51 % while the same from WPL was negative. With the supplement diets, the DCP of SR leaves improved slightly to 55 % but increased greatly in WPL to 51 %. From the village survey, the cattle in Berege suffered from lack of high quality feeds resulting in body weight losses during the later part of the dry season despite the bigger cultivated crop field farms than in Kilimanjaro region. With small areas of land in Kilimanjaro region, less than 1.5 ha, the maize fractions alone harvested before and after grain harvest accounted for over 39 % of the total annual cattle feed2 requirement while in Berege the combination of all dry residues after harvest (maize, sorghum and millet) formed 42 % of the total annual diet. This made the dependence of natural pasture in Kilimanjaro region to be only 28 % while in Berege village the cattle were still depending on 40 % natural pasture for the annual feed resources. Since the defoliation of maize and sorghum vegetative parts had no deleterious effects on the final grain yield, the technique should be introduced in Central Tanzania so as to make use of the enormous green materials lost in the wet season to be available in dry season. Their higher feeding value also will be an advantage to the farmers as they will buy less supplements to be added . to the forage to meet the animal requirements for maintenance and production.
Influence of quality attributes on the market value of fresh sweet potato tubers and processed cassava.
(Sokoine University of Agriculture, 2001) Ndunguru,Gabriel t.
Cassava (Manihot esculenta Crantz} roots and sweet potato (Ipomoea batatas (L) Lam) tubers are important staple food crops in several areas of Tanzania. Studies were conducted in Mwanza and Dar es Salaam markets in order to assess the factors that influence the quality and market value relationship of fresh sweet potato tubers and processed cassava roots. Consumers and traders in Mwanza preferred sweet potato tubers which are wholesome and free from infestation. White processed cassava root products were preferred by traders and consumers in Mwanza. Valuation assessment made on sweet potatoes showed that, broken, cut and weevil infested tubers sold were at 12.1, 14.2 and 36.6 percent discount respectively. Average valuation discount of processed cassava roots were 10 to 15 for yellow, 20 to 25 for greenish and 35 to 40 percent for dark product. Causes of losses in quality of sweet potato tubers were due to operations related to handling and transportation. Occurrence of broken tubers, skinning injury and cuts increased significantly with handling and transportation (P < 0.001). The largest loss in quality occurred between the lakeshore and the port at Mwanza when sacks were loaded and unloaded from the ship and handled at the port.iii Broken sweet potato tubers and skinning injury increased significantly ( P < 0.001) during handling and transportation from Gairo to Da es Salaam Impact shock loggers provided a low cost method for comparing the handling of sacks during transportation. Shock impact record increased with increase in the height form which sweet potato sacks were dropped (R2 adjusted = 0.875). Multiple linear regression analysis indicated that the number of impact in the category between 0.2 and 2 g significantly correlated with skinning injury (P=0.001), (R2 adjusted =0.651) and broken tubers (P=0.001), (R2 adjusted = 0.407) respectively. Weight loss during storage increased significantly (P=0.01) with shock impact and skinning injury. Dropping sacks of sweet potato tubers significantly (P < 0.01) increased the occurrence of broken tubers The use of cardboard boxes filled with fewer tubers instead of overfilled polypropylene sacks and adoption of improved management procedures in the handling and transport are recommended.
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. G
A 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.
Detection of proteolysis in milk by four selected methods
(The University of Reading, 2009) Chove, Lucy Mlipano
Sensitive 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.
Status assessment and roadmap for improvement of food safety management systems in Africa: the case of Tanzania
(Ghent University, 2015) Kussaga, Jamal Bakari
Chapter 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.
Drying of paddyunder hermetic storage conditions in Burundi
(Sokoine university of agriculture, 2022) Ahishakiye, Dionise
This study assessed the extent to which rice producers from Kidwebeziirrigation scheme could know their productivity loss during post-harvest activities and assessed the performance of drying and storing paddy in Grain Safe Dryer. To achieve these objectives, first simple random sampling was used to select 147 rice farmers in the study area. The collected data were subjected to analysis where output responsiveness with respect to each of the inputs, technical, allocation and economic efficiencies was estimated. Statistical Package for Social Sciences (SPSS) analysis was used to estimate the perception of paddy loss during post-harvest activities. The study further assessed factors affecting loss levels among rice producers. Grain Safe Dryers were installed to assess the performance during drying and storage of paddy. The study applied GENSTAT to analyse the data from using Grain Safe Dryer to dry and store paddy. Findings of this study reveal that the paddy lost during post-harvest activities were between 0 and 9%.Furthermore, the results show that the major factor affecting post-harvest losses in the study area was the material used in post-harvest activities. The study showed that the Grain Safe Dryer had high drying performance comparing to the sun dried paddy. Moisture contents of dried paddy were varied in sun drying and in the two Grain Safe Dryer units with the changes in atmospheric conditions. The initial moisture content was 25.3%, which decreased until it all reached 11.7% (in 19 days) in Grain Safe Dryers and 13.9% (in 3days) under sun drying. In case of germination percentage it was found to be higher (85.2%) in Grain Safe Dryer compared to sun drying (80.8%). Quality of rice after milling was found to be better (80%) in Grain Safe Dryer than sun drying (30%).On the other hand, seeds handled in Grain Safe Dryers gave higher germination rate and quality due to moisture content removed slowly during drying compared to sun drying. However, in terms of moisture removed, good quality, and germination percentage in Grain Safe Dryers were better compared to the sun dried paddy. However, it is recommended to carry more studies on Grain Safe Dryer to be assessed in different ecological zones before wider dissemination of the hermetic storage system for use as a dryer.
Attitude towards learning food and nutrition subject and eating behaviours of ordinary level secondary school students in Dodoma region.
(Sokoine University of Agriculture, 2022) Songo, Vashty Nyabhigeso
The learning outcome of food and nutrition subject depends on attitude of the leaners towards the subject. In Tanzania, food and nutrition subject is taught in selected secondary schools at the ordinary level education and in even fewer schools at the advanced level. This study aimed to determine whether the attitudes towards learning food and nutrition subject influence eating behaviours of secondary school students. Data were collected in Dodoma region from three purposively selected secondary schools. The study involved 381 students who were randomly selected whereby 194 students opted and 187 did not opt to study food and nutrition subject. Nutrition information in the syllabus, teaching and learning materials were collected through documentary desk review. Students' attitudes towards studying food and nutrition subject and their eating behaviours were assessed through structured questionnaires that included, the dietary diversity component among others. Statistical Package for the Social Sciences (SPSS) Version 20 software was used to analyze descriptive and inferential statistics where t-test was conducted while qualitative data were analyzed by the text analytics program and interpreted according to the emerging themes. The study observed that syllabus had objectives that were relevant to the nutritional needs of the country. The subject specific textbooks were absent instead there were eleven (11) reference books used in all the surveyed schools. Those reference books had outdated nutrition information hence, not satisfactory to fulfil the need of the current syllabus and on address the existing problem of triple burden of malnutrition. Gender was found to influence choosing of the subject since mean attitude scores for males (M = 2.0154) which was half to that of females (M = 4.4995). Opting to study the subject influences eating behaviour significantly (p-value < 0.01). Among the 194 students who opted to study food and nutrition subject, 93% had proper eating behaviour because number of food groups eaten per day was five and above hence their dietary diversity score was above five (5). The students who had improper eating behaviour due to the fact that their diet consist less than five food groups was 7% hence their dietary diversity score was below five. The study concluded that students practice what was taught to improve their eating behaviour because students who opted for Food and Nutrition Subject had adequate dietary diversity in their diet compared to those who did not opt for studying the subject. The study recommends that, subject extracurricular activities on nutrition programs should be given to all students in order to emphasis and provide opportunity of improving their eating behaviour for their lifelong future benefits.
Awareness of aflatoxin contamination and safety of maize along supply chain in Kondoa and Chemba districts in Dodoma, Tanzania
(Sokoine University of Agriculture, 2022) Ndwata, Asha Hamad
Maize (Zea mays) is a staple food for the majority of people in Tanzania, which plays a key role in subsistence and as a cash crop among actors of the maize value chain. The study was conducted during the 2020–2021 cropping season in two districts, Kondoa and Chemba, in the Dodoma region of central Tanzania. The objectives were to assess stakeholders' awareness of aflatoxin contamination in maize (smallholder farmers, traders, and consumers), to assess post-harvest handling practices of maize among smallholder farmers, and to determine the current levels of aflatoxins B 1 contamination in maize. Structured questionnaires were used to collect the data. A cross-sectional survey was used in collecting primary data. A total of 380 respondents, including smallholder farmers, traders, and consumers from each ward, were selected. In addition, 90 maize samples (40 from smallholder farmers, 20 from traders, and 30 from consumers) were analyzed for aflatoxins using High-Performance Liquid Chromatography (HPLC). The results show about 56% of the smallholder farmers and 52% of the traders were aware of the contamination. However, the majority of the main stakeholder (consumer) was unaware of the contamination with aflatoxins (74%). Moreover, the result shows smallholder farmers had inadequate knowledge of best post-harvest practices and these were associated with post-harvest losses and the microbiological quality of maize. It was observed that the majority of smallholder farmers (75% ) used traditional post-harvest handling practices such as harvesting maize and placing it on the ground, storing maize in galleries, drying (on the ground); use of polypropylene bags as a storage facility. Few samples of the maize value chain were contaminated with AFB 1 and total aflatoxins. Furthermore, the result shows five-point six percent (5.6%) of collected samples were contaminated with aflatoxins B 1 , and 3.3% of the aflatoxins samples exceeded the European Union (EU) and Tanzania Bureau of Standards (TBS) regulatory limits for AFB 1 and were mainly collected from traders in Kondoa district. Extension workers should train farmers on effective post-harvest management practices of maize in order to minimize losses and improve the quality. In addition, efforts should be made to educate the general public, particularly consumers, about the dangers of aflatoxins contamination, and affordable techniques should be made available to maize farmers in the Kondoa and Chemba districts of Dodoma, Tanzania, in order to reduce grain losses and increase income and food security.
Effects of Hexanal and Calcium Chloride Post-Harvest Treatments in Management of Fresh Mango (Mangifera indica) Quality
(Springer, 2022-07) Baltazari, Anna; Mtui, Hosea D.; Mwatawala, Maulid W.; Chove, Lucy M.; Msogoya, Theodosy; Samwel, Jaspa; Paliyath, Gopinadhan; Subramanian, Jayasankar
Abstract Experiments were conducted at the Sokoine University of Agriculture to assess the effects of hexanal at (0.02%) (volume/volume) and calcium chloride (2%) (weight/volume), on post-harvest quality of mango (‘Palmer’ and ‘Apple’) under different storage conditions and durations. A three factors factorial experiment was used for each variety and replicated six times. The fruits were stored at ambient temperature (28 ± 2 °C) or reduced temperatures (18 ± 2 °C) storage conditions. Data included physiological weight loss (PWL), fruit firmness, total soluble solids (TSS), titrat- able acidity (TA), TSS/TA ratio, vitamin C, total flavonoids, reducing sugar and total sugars which was collected at 0, 4, 8 and 12 days after harvest. Results indicated that hexanal and calcium chloride significantly (p \ 0.001) reduced mango PWL and improved fruit firmness and TSS of both varieties compared to untreated fruits. Hexanal-treated fruits maintained high vitamin C, total flavonoids, total and reducing sugars irrespective of the storage conditions. Vitamin C and total flavonoids of mango fruits decreased with storage time, whereas total and reducing sugar contents increased with storage time. Both treatments maintained physico-chemical qualities of mango fruits, when stored under reduced temperature storage. Keywords; Physiological weight loss , Fruits firmness , Total soluble solids (TSS) , Titratable acidity (TA) ,TSS/TA ratio , Vitamin C , Flavonoids , Reducing sugar , Total sugar
Evaluation of quality of pumpkin and soy bean-seed blended maize flour
(SOKOINE UNIVERSITY OF AGRICULTURE,, 2023) Daza R. D
Maize is a major food staple in most of the sub-Saharan African countries. Maize flour is mostly rich in carbohydrates, which provide energy to the human body. Nutritionally, maize flour is deficient in the other major diet requirements of proteins, vitamins and essential minerals. In this study, maize flour was enriched using pumpkin and soybean seed flours and the sensory and nutritional qualities of the resulting composite flours were evaluated. Four formulations of maize, soybean and pumpkin seeds flours were preparedby compositing various proportions of each ingredient. The flours were produced by grinding the seeds using a hammer mill to a particle size fine enough to pass through a 1 mm sieve size. The composite flours were then used to prepare stiff porridges (ugali), which is the popular format of preparation for this meal. Nutritional and sensory quality of the flours and stiff porridges were evaluated. The nutritional quality parameters included crude protein, which was found to increase from 8.1% (w/w) in the plain maize flour to up to 24.09% in the blended flour formulations; crude fibre increased from 7.3% to13.45%; crude fat from 3.6% to 32.26%; ash from 1.09% to 3.44%; and moisture content was increased from 8.1% to10.29%. Micronutrient parameters evaluated included Vitamin A which was found to increase from 0.00μg/g to 78.82 μg/g; Folic acid from 2.5 μg/g to 5.33 μg/g; Vitamin C from 0.00 mg/100g to 12.23 mg/100g; Zinc from 1.8 mg/100g to 3.43 mg/100g; and Iron from 3.5 mg/100g to up to 20.81 mg/100g, in the formulations. Sensory attributes evaluated for the composite flour ugali were aroma, color, texture, general appearance, smell, flavour, hardness, springiness, oiliness, taste and general acceptability. A 9-point hedonic scale was employed in the sensory evaluation, alongside instrumental evaluation using a laboratory texture analyzer. There was no significant difference in smell, appearance, texture, flavour, hardness, springiness across the four formulations among the panelists. The mean score was above 5 for all parameters, which is in the middle of the 9- point hedonic scale. These findings indicate that generally all the formulations were accepted. Formulation F4 (8.47%) had the highest score among the formulations. The instrumentally evaluated results indicated significant differences in hardness, cohesiveness and springiness in the stiff porridge samples. From the human sensory evaluation, all samples were accepted regardless of their instrumentally evaluated differences, indicating that the differences were not enough to substantially influence the human sensory organs. The effect of cooking was established by evaluating the vitamin A and B9 losses. The vitamin A losses after cooking were established to vary in the range from a minimum of 0.06% to a maximum of 0.88% among the formulations. The vitamin B9 losses after cooking were established to vary by a minimum of 0.05% to a maximum of 1.04% among the formulations. Pumpkin and Soy bean seeds flour improved the nutritional quality of the stiff porridge composite flours. The micronutrients compositions were increased due to the added ingredients of soy bean and pumpkin seeds flour. The sensory evaluation of stiff porridge from all formulations and control sample indicated that all formulations were acceptable. Therefore the inclusions of pumpkin and soy bean seeds flour in the levels used in this study improved maize flour stiff porridge but did not significantly affect the product acceptability.
Prevalence and factors associated with undernutrition among under-five children in Gairo district, Morogoro, Tanzania.
(Sokoine University of Agriculture, 2023) Mohamed T.M
In Tanzania, undernutrition in children under the age of five years is a significant public health concern. Despite efforts made to combat undernutrition still Tanzania has the highest prevalence of undernutrition. Therefore, this study aimed to assess the prevalence and associated factors of undernutrition among children under-five years of age in Gairo district, Morogoro region. In three areas of the Gairo district, 300 children under the age of five years and their mothers or guardians participated in a cross-sectional household survey. A semi- structured questionnaire was used and anthropometric measurements were taken using standard procedures and techniques. The number of food groups consumed by children the day before were from 0 to 7, they were added up to create a dietary diversity score. A score of four or more food groups was then utilized as the minimum dietary diversity. The prevalence of undernutrition was assessed using the standard measures of stunting, wasting, and underweight utilizing the low indices of HAZ, WAZ, and WHZ. To determine the rate of undernutrition in the district, children were divided into distinct anthropometric failure categories using a composite index of anthropometric failure (CIAF), which was calculated using the low indices of HAZ, WAZ, and WHZ. Odds ratios with 95% confidence intervals and p-values of 0.05 or less were used to identify factors associated with undernutrition. According to this study, the prevalence of stunting was 54.3% (severe stunting 26.3% and moderate stunting 28%), underweight 23.3% (severe underweight 7% and moderate underweight 16.3%) and wasting 3.7% (severe wasting 1.3% and moderate wasting 2.4%). %). The main factors that showed positive association were; maternal occupation was associated with stunting (p = 0.002) and underweight (p = 0.026). The age of the child was linked with stunting (p = 0.030), the age of the mother during pregnancy was connected with being underweight (p = 0.046), and the area of residence was associated with stunting (p = 0.000) and underweight (p = 0.008). The CIAF showed a prevalence of undernutrition of 57.3%, with children experiencing single failure at a rate of 105 (61%), double failures at a rate of 62 (36%) and triple failures at a rate of 5 (2.9%). Factors that were significantly associated with CIAF were the nearest health facility (p = 0.014; OR: 0.504 (0.291-0.873)), location of delivery (p = 0.000; OR: 0.717 (0.107-0.490)), and water supply (p = 0.001; OR: 0.452 (0.283-0.722)) , type of latrine used (p = 0.000; OR: 21.338 (9.807-46.427)), household solid waste disposal method (p = 0.012; OR: 1.806 (0.682-1.964)) , birth weight (p = 0.000; OR: 5.400 (2.625-11.109)) and marital status (p = 0.00; OR: 0.403 (0.240- 0.676)). Therefore, Governmental and non-governmental nutritional and health interventions that aim at the whole regions throughout districts are required, emphasizing enhancing the living conditions of children by ensuring that, they have equal access to food, water, and health care resources.
Assessment of indoor storage technology on white colour sweet potato tubers (Ipomoea batatas L.Lam) in Morogoro, Tanzania
(Sokoine University of Agriculture, 2024-04) Kimako, Joseph R.
Sweet potato (Ipomoea batatas L.Lam.) is a dicotyledonous plant grown as a tuber crop. Sweet potatoes originated from tropical America (Coop, 2010). Sweet potatoes are widely cultivated mainly around the lake zone, eastern zones, southern highlands, and northern parts of Tanzania (URT, 2016). It is grown by 771,257 households during short rainy and long rainy seasons, with an estimated annual production of 504,346 tonnes (NBS 2012). Sweet potato tubers contribute to food security and income generation (Ahmad et al., 2014). Sweet potatoes' high perishability after harvesting is one of the major factors limiting their potential. Insufficient information concerning efficient storage technology limits farmers and traders from choosing the best technology to reduce losses. The research by Teye et al. (2011) compared two storage technologies: the Purpose-Built Evaporative Cooling Barn and Modified Pit Storage under Ghana conditions, neglecting other sweet potato storage technologies. Further research by Mpagalile et al. (2007) used the traditional pit, improved open pit, improved housed pit (mjinge) and raised woven structure (Kihenge) to evaluate the storability of sweet potato under Tanzania conditions neglecting other sweet potato storage technologies. Purpose Evaporative Cooling Barn and housed pit storage are still techniques used to attain optimum temperature and relative humidity for sweet potato storage with temperatures between 12.5°C and 15°C and relative humidity from 85% to 90%. Nevertheless, their adaptability to small-scale farmers and traders in developing countries like Tanzania is limited due to their high initial capital and high running costs for White-coloured sweet potato tubers. Small-scale farmers and traders are in high demand for storage technology, which is low in capital and running costs. Indoor storage technologies are a better choice as they maintain proper storage temperature and relative humidity through ventilation and are used in hot and arid areas (Baimey et al., 2017). In this technology, White coloured sweet potato tubers can be stored with minimum changes in colour, weight, rotting and firmness (Gopala, 2015).This study aimed to assess indoor storage technology on white colour sweet potato tubers (ipomoea batatas l.lam) in Morogoro, Tanzania, that will help to minimise losses of white sweet potato tubers. According to the findings, the most significant cause of post-harvest losses was rodent attack, which was reported by 26.53% and 25% of farmers and traders in Gairo and Morogoro municipalities, respectively, and the extent of white-coloured sweet potato tuber losses observed was 18.36% of farmers and traders in Gairo and 79% of farmers and traders in Morogoro municipality have reported to suffer from moderate post-harvest losses. White-coloured sweet potato tubers stored in ventilated bags and the improved traditional raised platform resulted in a weight loss of 49.4% and 68.7%, respectively. It was also observed that the improved traditional raised platform had a significantly high total soluble content /concentration, with a value of 21.27%. In comparison, Ventilated bags resulted in a Total soluble solid content of 17.02 %, which was significantly low. Furthermore, results show that Ventilated bags had the lowest beta carotene content (8.72 μg/g) compared to other treatments. Results indicate that traders’ source of funding for their sweet potato selling activity was own/self-financing, estimated at 70%, loans estimated at 19.37%, and remittances estimated at 10.63%. Also, the study's findings demonstrate that the single and multi-stage channel systems are the two main sweet potato marketing channels. Retailers constitute 57.5% of respondents, wholesalers 27.5%, and other trades (Middlemen/SME processors) 15%. Furthermore, a study indicated that 21% of traders produce sweet potatoes on their farms, and 97% of merchants purchase sweet potatoes directly from farmers also, 42% purchase sweet potatoes through wholesalers/aggregators. Results continued to reveal that by using ventilated bags storage technology, farmers and traders could earn higher profits, which was Tsh 19,000/= more than other storage technologies (improved traditional raised bamboo buckets and woven Polypropylene Bags.The study results indicate a need to improve post-harvest loss awareness among white-coloured sweet potato farmers and traders to reduce loss and thus begin producing profitably. Also, controlling rodents, avoiding injury, building a proper storage facility and inspecting the stores regularly are the most important aspects to consider when preventing losses. Also, findings suggest that storing white-coloured sweet potato tubers in ventilated bags is appropriate. Using ventilated bags can also be effective when storing undamaged sweet potato tubers. Farmers and traders are advised to sort and grade their tubers before storage. Furthermore, additional research studies should be conducted to develop awareness of other types of storage and methods for reducing sweet potato losses to impact food security in society.
Potential of moringa oleifera leaf extract in ground beef preservation
(Sokoine University of Agriculture, 2024-05) Mwankunda, Lucy J.
This study explored the diverse potential of Moringa oleifera leaf extract as a natural preservative in ground beef, with a specific focus on its impact on microbiological and physico-chemical properties during refrigerated storage. The study explored varying concentrations of Moringa oleifera (0.5%, 1%, 1.5% and 2.0%) in comparison to a preservative-free control group, investigating their impact on microbial parameters, including Total Bacteria Counts (TBC), Total Coliform Count (TCC), Staphylococcus, Salmonella, and E. coli. The results unveiled a dose-dependent relationship, where in all concentrations exhibited lower TBC compared to the control group, with the 2.0% concentration demonstrating the most substantial reduction, underscoring Moringa oleifera's potential to inhibit bacterial growth in ground beef. In terms of TCC, higher concentrations of Moringa oleifera showed enhanced effectiveness in reducing coliform bacteria, particularly the 1.5% and 2.0% concentrations, which significantly decreased counts by 31% and 32% compared to the control group. The study also spotlighted Moringa oleifera's dose-dependent antibacterial activity against Staphylococcus and E. coli, with escalating doses correlating with significant reductions in these microorganisms. These findings collectively suggest that Moringa oleifera holds promise in augmenting food safety by curbing the proliferation of harmful bacteria, thereby acting as an effective natural preservative and enhancing the microbiological quality of refrigerated ground beef. The investigation extended to the antimicrobial effects of Moringa oleifera aqueous extract on ground beef, assessing physico-chemical, microbial, and organoleptic qualities during refrigerated storage at 4°C. The results revealed that the 1.5% crude extract significantly improved (p<0.05) various sensory attributes, including pH, juiciness, texture, flavor, taste, and overall acceptability, surpassing both the control and other treated samples. Furthermore, microbial load, as indicated by the Aerobic Plate Count (APC), exhibited a significant decrease in treated samples (p<0.05), with the 2% treatment proving to be the most effective. The color parameters (L*, a*, b*) of ground beef were influenced by Moringa oleifera extract, manifesting a decrease in values, particularly with the 2% concentration. Notably, the pH of ground beef experienced a slight increase during storage, but Moringa extract did not significantly (p>0.05) impact this parameter. In conclusion, this study underscores the potential of natural additives such as Moringa oleifera to not only extend the shelf life of ground beef but also to significantly enhance its microbiological and sensory properties. This aligns with the escalating consumer preference for safe and natural food products, emphasizing the need for further exploration and application of Moringa oleifera in the realm of food preservation and safety.

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