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Sokoine University of Agriculture  Institutional Repository (SUA IR). This repository was built and is maintained by the university library  (Sokoine National Agricultural Library-SNAL) , in order to collect, preserve and disseminate scholarly output generated by University research community (staff and students) members.

This repository hosts a variety of openly accessible materials including: scholarly articles and books, theses and dissertations, conference proceedings and technical reports. For assistance about depositing your research output in the repository click here. SUA IR Policy  click here or any queries contact us at snal@sua.ac.tz.

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Recent Submissions

Influence of botanic and geographic origin on quality of honey from Tanzania.
(Sokoine University of Agriculture., 2016) Shekilango, Salama Ghuio
In 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.view
The impact of fairtrade standard on smallholder coffee farmers and their organisations in selected areas in Tanzania .
(Sokoine University of Agriculture, 2008) Shayo Hellen Mungubariki
Fairtrade has become an alternative approach to convectional trade practices over the past decade. In Tanzania, Fairtrade organisations started doing transactions with Tanzanian coffee producers since early 1990s. Participation in Fairtrade initiatives has brought range of benefits and constraints to the producers and their respective communities. There have been several structural changes since 1999 when the last Fairtrade impact study was done in Tanzanian coffee industry. Up to 2008, Fairtrade standard is yet to be recognized by Tanzania Coffee Board in auction system, though direct export regulations allow the fine washed Fairtrade Arabica coffee of top grades. There is no significant statistical difference in coffee yield and net coffee income (P<0.05) among sampled FT fanners compared to non FT farmers. Harvesting of old coffee trees and high management and operation costs facing FT farmers are among the reasons for insignificant difference in coffee yield and net income. FT premium at KNCU is retained for investment in crop quality and infrastructure improvements or community projects, while at AKSCG it is distributed to the farmers groups for infrastructure construction and/or improvement. FT farmers organisations are guaranteed coffee market, accessibility of imperative market information and organizational capacity building training by Fairtrade organizations (ATOs). Inability to sell all FT coffee stock through FT channel, low level of awareness on FT market, networks, premiums or price floors among FT producers were observed to be some of the constraints related to Fairtrade compliance. FLO should appraise its generic standard concerning value addition to raw coffee to provide smallholder farmers organisations with an opportunity to earn more. FT processors and millers can pursue TCB to recognize Fairtrade standard in auction iii system, this would be further step in creating FT market’ awareness among stakeholders in the coffee industry. FT farmers organisations should improve awareness on Fairtrade standard through educational training so that farmers can make informed decision concerning compliance.
A comparative analysis of levels of vulnerability of livelihood assets to gas extraction operations: evidence from Mtwara rural district, Tanzania
(Tanzania Journal of Community Development, 2023-05-07) Musoma, Beston M.; Nyanda, Suzana S.; Muhanga, Mikidadi I.; Massawe, Fatihiya A.
Extractive investments adversely affect local communities across the globe. Tanzania experiences new gas extraction operations (GEO) but with scanty information on how they influence the levels of vulnerability of livelihood assets among rural communities. As such,there is a need to empirically understand wplaces are more vulnerable than others so that livelihood enhancement actions can be performed following gas extraction operations. This article examined the levels of vulnerability of livelihood assets among communities residing near and distant villages to gas extractive fields and processing plants. A cross-sectional research design was employed, and 260 respondents were sampled proportionally from village registers.The sample was complemented with 15 key informant Interviews (KII) and four focus group discussions (FGDs). A comparative analysis was performed using Livelihood Vulnerability Index (LVI). The results revealed that distant villages had the highest level of food accessibility and water accessibility. Also, neighbouring villages have the highest level of vulnerability on land ownership. Likewise, nearby villages had a moderate level of exposure to livelihood strategies and gas extraction activities. To conclude, distant villages had a higher level of vulnerability to food access, water access, and socio-demographic profile components. Whereas nearby villages had the highest level of vulnerability on land ownership and gas extraction operation components. Therefore, to lessen the food vulnerability among households, the government and donors should prioritize income generating and food security programmes among households.
Analysis of urban markets-linked cassava value chain: A case of Morogoro rural district, Tanzania.
(Sokoine University of Agriculture., 2010) Sewando Ponsian Thomas
This study was carried out to examine the value chain for cassava in order to determine strategies needed to enhance profitable participation of smallholder farmers in the cassava value chain for reducing income poverty in Tanzania. Specifically, the study intended: (i) To analyse the structure of the cassava value chain and coordination among actors in the value chain, (ii) To analyse profitability of alternative cassava value chain strands and identify determinants of profitability and (iii) To analyse farmers’ preferential choice decisions of alternative cassava value chain strands and identify their determinants. A structured questionnaire was used to collect data from 150 fanners from three villages of Morogoro rural district. Data were analysed using descriptive and quantitative methods. Profit and marketing margins along the cassava value chain were computed. ANoVA was employed to measure the variation in profitability among the smallholder farmers. Factor analysis was used to identify the variables for further analysis on likelihood of farmers to participate in alternative cassava value chain strands. Linear and Poisson regression models were estimated to identify the determinants of profitability and farmers’ preferential choice decisions in risks respectively. Results show that there was no significant variation in profitability between the villages at p<0.05 level. Profit margins varied significantly among cassava value chain actors. The factors that contributed to the profit margin at farm gate were farm size, experience, total family labour, group participation, non-crop livelihood sources and food insecurity. Results also indicate that farmers have positive risk attitude towards participation in the alternative cassava value chain strands and farm size, experience, female-headed households and land-holding had influenced the farmers’ preferential choice decision. Recommendations for enhancing farmers’ participation in profitable cassava value chain strands are strengthening coordination, provision of improved cassava varieties and introduction of cassava processing technologies.
Adoption of cassava processing and utilization technologies: A case of Mtwara rural and Newala districts, Mtwara region
(Sokoine University of Agriculture., 2011) Shomari Mgeni Shamte
The study was conducted on adoption of cassava processing and utilization technologies in Mtwara region. The main objective of the study was to determine the status of cassava processing and utilization technologies in Mtwara region. Structured questionnaire and Focus Group Discussion (FGD) were used to collect information from cassava fanners. Random sampling was used to draw respondents for interview. Sample size was 120. Descriptive statistics, logistic regression and gross margin were used for data analysis. Results revealed that, both traditional and improved cassava processing technologies were used by respondents. It was found that 77% of the respondents used traditional cassava processing methods and about 17% were using both traditional and improved processing technologies. Also, the findings showed that, institutional support to farmers was an important factor in adopting improved cassava processing technologies by farmer groups. The coefficient of the institutional support was statistically significant at 0.05 probability level. Age of respondents, occupation and marital status of respondents were not statistically significant. Gross margin analysis showed that improved cassava processing technologies contributed relatively high to households income with a gross margin of Tsh 78 400 per tonne when compared to traditional processing methods with a gross margin of Tsh 11 774 per tonne of fresh roots processed to flour. This study recommends that, the government and other agricultural stakeholders need to promote and educate fanners on the importance of improved cassava processing and utilization technologies to human health, food security and poverty alleviation. In order to improve market of cassava products, the government should promote and encourage food processing industries to use cassava as an ingredient in some of food products to increase the demand for cassava products and accelerate the adoption of improved cassava processing technologies.