Articles, Conference and Workshop Papers Collection

Permanent URI for this collectionhttp://10.10.97.169:4000/handle/123456789/4447

Browse

Now showing 1 - 20 of 53

Sensory evaluation of different preparations of cassava leaves from three species as a leafy vegetable
(African Journal of Biotechnology, 2013-11-13) Umuhozariho, M. G; Shayo, N. B; Sallah, P. Y. K; Msuya, J. M
Cassava leaves are largely consumed in Africa and are among the top three African indigenous vegetables rich in nutrients. Leaves from bitter (Manihot utilissima), sweet (Manihot dulcis) and wild (Manihot glaziovii) species of cassava were cooked by boiling in salted (sodium bicarbonate and table salt) water with the addition of palm oil and ground-nut paste, following processing by “pounding”, “pounding and then drying” and, “drying and then pounding”. The drying was done in tunnel solar drier at temperature of 65°C on average. Nine samples (three species x three processing methods) were evaluated by 31 panelists, using a five point hedonic scale, where 5 = like very much and 1= dislike very much. Cassava species affected significantly (p = 0.0047; 0.0206) scoring for texture and overall acceptability, respectively, but not for colour, aroma and taste. Processing method highly significantly (p< 0.0001) affected all the sensory attributes scoring. Leaves from all three species were liked as leafy vegetable, except when pounded after drying.
Physico-Chemical and grain cooking characteristics of selected rice cultivars grown in Morogoro
(2006) Shayo, N. B.; Mamiro, P.; Nyaruhucha, C. N. M; Mamboleo, T
A study was carried out at Sokoine University of Agriculture to characterize the local rice varieties grown in Morogoro Region basing on their physical-chemical characteristics and cooking quality parameters. Five cultivars of rice were analyzed and these included Kaling’anaula, Kihogo Red, Salama M17, Supa and Salama. The samples were collected from Crop museum, SUA. The chemical analysis was done to determine the proximate composition, gelatinization temperature and gel consistency as main determinants of cooking quality, sensory evaluation tests was done as determinants for consumer acceptance. The proximate composition results indicated protein content values between 7.94 and 9.46%, ash content between 0.55 and 0.97%, fat content between 0.57 and 0.85%, fiber content between 0.29 to 0.73%. The amylose content values were between 18.25 and 19.25%. The gel consistency results showed that all cultivars analysed were hard with the gel length values between 27.50 and 31.80 mm There was a significant differences in composition as well as acceptability between the varieties. In all aspects, Supa cultivar appeared to be the most superior with mean score of 4.30 while Kihogo Red was the least superior with mean score of 2.93. The differences in the cultivars could be from environmental as well as genetic factors. This pauses a need for more studies to be directed to these factors in order to come up with useful alternatives on how to manipulate them so as to improve the cooking quality parameters, improve production of the local rice cultivars and increase the market demand for local rice.
Utilization of cassava leaves as a vegetable in Rwanda
(Rwanda Journal, 2011) Umuhozariho, M. G; Shayo, N.B; Msuya, J. M; Sallah, P. Y. K
Cassava (Manihot esculenta Crantz) leaves is an important vegetable in Rwanda. The objectives of this study were to determine cassava species from which leaves are harvested as vegetable and identify leaf preparation methods, consumption rate, price variation, storability and perception of post-harvest losses. A pre-tested structured questionnaire with closed and open-ended questions was administered to stratified groups of cassava leaves producers and consumers in four purposively selected sectors of Ruhango District and retailers in the main markets of Ruhango and Kigali city. In total, 171 respondents were interviewed from 11 to 26 August 2011. Cassava leaves are highly consumed in Ruhango District as 96.0 % of families harvested leaves for food. On average, 17.5 % of farmers sell cassava leaves that are retailed in markets of towns and cities including Kigali City. Sweet (Manihot dulcis), bitter (Manihot utilissima) and wild (Manihot glaziovii) are the cassava species from which leaves are consumed as vegetable, but the leaves of wild cassava are preferred by 66.0 % of consumers. Prices of cassava leaves varied significantly (p=0.0182) according to season with higher prices in the dry than rainy season. Prices of leaves at farm gate and retail levels were highly different (p= 0.0016), averaging 32 and 65 Frw by bunch in the rainy season, respectively. Despite the high consumption and trade of cassava leaves, post-harvest losses were high, especially in the rainy season. Cassava leaves were mainly cooked fresh, but 15.4 % of households processed leaves by sun drying. The storage period was extended to two months by sun-drying. In each case and, prior to cooking, cassava leaves were pounded. Cassava leaves are considered as a favourite and nutritive vegetable and technologies to improve storability, value and trade are needed. Assessment of effects of processing on nutritional quality and safety is also important
Isolation and characterisation of yeasts and bacteria from Mbege- An opaque Beerr made from millet malt and banana juice
(Tanzania J. AgriC. Sc, 1998) Shayo, N. B; Nnko, S. A. M; Gidamis, B
The micro organism involved in the traditional fermentation process of "mbege ",an indigenous Tanzanian alcohol beverage prepared from malted millet and banana juice were isolated and identified saccharomyces cerrevisiae and lactobacillus plantarum whereidentified as yeast and bacteria responsible for the fermentantion process respectivelly. The main spoilage micro-organism of Mbege was identified as of Acetobacter species. A diverse range of micro-organisms were also identified in the mlliet malt .The coliforms were the predominant ones followed by pseudomonads, lactic acid bacteria(LAB) and yeasts. The presence of high numbers of coliforms (l.98+0.20x 107 ) in millet malt poses no health risk as they are destroyed during porridge preparation. In addition the low PH ( ph4.5 ) of mbege in hibits the growth of coliforms and other pathogenic bacteria. The diverse range of micro-organisms founds in millet malt was an indication of unhygienic handling of millet malt,
Colour and antioxidant activities of honey from different floral sources and geographical origins in Tanzania
(Tanzania Journal of Agricultural Sciences, 2016) Shekilango, S. G; Mongi, R. J; Shayo, N. B
Honey is a sweet, yellowish liquid that is produced by honey bees and it has been used for many years for nutrition and therapeutic purposes. Its therapeutic potential has been associated to its antioxidant capacity which plays an important protective role in human health through scavenging of free radicals in the human body and thereby decreases the amount of free radical and damage to biological molecules like lipids and DNA. This study was carried out to investigate the effect of floral source (miombo and acacia) and geographical origin (Central, Coastal, Lake, Northern, and Southern Highland) in mainland Tanzania on colour and antioxidant activity of honey samples. Colour, total flavonoids content (TFC), total phenol phenolic contents (TPC) and antioxidant activities of the samples were evaluated using UV/Vis spectrophotometer, Folin-Ciocalteu reagent and Ferric Reducing Antioxidant Power (FRAP) methods respectively. There were significant (p<0.05) differences in all parameters assessed between floral sources. Miombo honey samples had higher pfund values (mm) for colour ranged from 31.55 mm (white) to 143.98 (dark amber) than acacia samples with values ranged from 17.33 (extra white) to 62.28 mm (light amber). Miombo samples had higher TFC values of 13.5±0.25-39.9±0.42 mgRE/100g DM) and TPC of 127.9±2.5-395.2 mg GAE/100g DM) than acacia samples with values of 12.7±0.60-17.5±0.38 mgRE/100g DM and 119.5-168.2 mg GAE/100g DM respectively. Similarly, significantly (p<0.05) highest and lowest FRAP values of 488.9-956.3 and 252.6-368.26 μM Fe2+/100g DM were observed in Miombo and acacia honey samples respectively. Moreover, variations in colour, TFC, TPC and FRAP between zones were significant (p<0.05). Within the miombo samples, northern and coastal zones had respective lowest and highest values whereas central and northern zones had respective lowest and highest values within the acacia samples. A strong correlation (R2= 0.942) between TPC and antioxidant activities of honey samples suggest that the antioxidant of honey is highly linked to TPC. Therefore, the study has revealed that, floral sources and geographical origins have varied significant effects on colour, flavonoids, total phenols and antioxidant activities of Mainland Tanzania honey. Honey samples from miombo floral source had higher antioxidant activities and hence their consumption is more recommended.
Physical-chemical properties, storage stability and sensory evaluation of pumpkin seed oil
(2006) Lyimo, M. E.; Shayo, N. B.; Kasanga, A.
Physico-chemical properties, storage stability and sensory evaluation of pumpkin seed oil was carried out and compared with other vegetable oils commonly used in Tanzania in order to evaluate its potential as an edible oil with the aim of promoting its utilization in rural areas. Pumpkin seeds were collected from different farmers in three villages in Morogoro Region, Tanzania. The proximate composition of the seeds was determined using standard methods. Storage stability of the oil was evaluated by monitoring the physicalchemical properties of the oil for 15 weeks following the standard procedures. Acceptability of the oil was determined using a 5 point hedonic scale. Pumpkin seeds contained 34.7%, 15.9%, 3.85% and 44% protein, fat, fibre and carbohydrates, respectively. The specific gravity of the pumpkin seed oil was 0.92; peroxide value 4.6 meq/kg; iodine value 108.4; saponification value 173.0 and acid value of 0.5 mg KOH/g. The pumpkin seed oil was organoleptically acceptable in terms of flavour, taste and odour. The pumpkin seed oil conforms very well with other common edible vegetable oils in Tanzania in terms of physical-chemical properties and sensory evaluation. Farmers should be encouraged to utilize pumpkin seed oil for household consumption
Nutritional status of underfive Children in a Pastoral Community in Simanjiro District, Tanzania
(Tanzania Health Research Bulletin, 2006) Nyaruhucha, C. N. M; Mamiro, P. S; Kerengi, A.J; Shayo, N.B
A study was conducted in Simanjiro district in northern Tanzania to determine the nutritional status of underfive children in a pastoral community. Weight and height measurements were carried out on 250 children and that of mean upper arm circumference (MUAC) on 226 children. The z-scores of weight-for-age, weight-for-height and height-for-age indicated that 31.2% of the children were underweight and 6.0% were severely underweight. Wasting was observed in 17.2% children of whom 3.2% were severely wasted. Severely stunted children were 3.2% while 14% were moderately stunted. Measurements of MUAC indicated that 35% and 3.5% of the children were moderately and severely undernourished, respectively. The nutritional status of the children under study was slightly lower than the national average. In conclusion, malnutrition in Simanjiro district is prevalent, and therefore, appropriate multidisciplinary approach on nutrition education, environmental sanitation and hygienic practices at family and community level need to be promoted to reduce childhood illnesses thereby increasing child health and nutritional status.
Uranium uptake by selected food groups and the associated health effects to the residents of Bahi district in Tanzania
(Sokoine University of Agriculture, 2014) MZIRAY,ZAINAB JURAJI
Assessment of Uranium levels in selected food groups and products with the associated health effects to the residents of Bahi District was carried out. The objective was to come up with information on whether these food groups contain significant amounts of Uranium and if the community has been affected by uranium related diseases. This was done to bring the awareness to the vulnerable communities and Tanzanian Government in general on the environmental and health hazards posed by the presence of Uranium deposits in the study area. Selected food groups and products used to assess uranium levels were maize, finger millet, rice. cassava leaves, salt, soda ash, fish, flamingo meat and water. These food groups were collected from three different villages of Bahi district. The levels of uranium in the named food groups and products (in pg kg-1) were determined by using ICP- OES instrument. Maize and rice had uranium concentration below detectable limit (<10), millet was found to range 11.88 - 25.13; cassava leaves ranged 12.37 - 13.83. Fish had uranium content of 17.98 in the skin where as muscles had uranium level below detactable limit. Flamingo bird had uranium level of 31.78 in the liver , where as other tested parts had below detectable limit. Soda ash was found to have uranium content of 1910, whereas salt had uranium content below detectable limit. The results for water from different sources in three villages have shown that, in Hindi village, Playa lake water had uranium concentration of 1233, while drinking water from one well had uranium content of 95.4, water from a well used for irrigation had uranium content below detectable limit. In Mpamantwa village, the water from one well had uranium content of 16.7 whereas other sources had uranium level below detectable limit. In Bahi village, the water from one well had uraniumiii level below detectable limit while river water had uranium concentration of 67.6 and another well had uranium content of 16.6. Secondary data from hospitals have shown that Bahi communities have not been affected by uranium exposure through foods consumed. However, further research need to be conducted on domestic animals since they use lllindi Playa lake water for drinking which was found to have high uranium concentration.
Effect of processing methods on the micronutrient profile, colour, and anti- nutritive components of justicia heterocarpa (mwidu)
(European Journal of Nutrition & Food Safety, 2025-02-05) Swai, Zenorina Aloyce; Nyamete, Frida Albinus; Silayo, Valerian. C. K.
Justicia heterocarpa (mwidu) is a popular indigenous leafy vegetable picked wild in rural regions of Morogoro, Tanzania, during the wet seasons. This research examined the impact of processing on micronutrients, total phenols, and anti-nutrient content. The fresh leaves (FL) underwent direct shade drying (UBLDDR), blanched shade drying (BLDR), blanched oven drying (BLDO), fermentation (FFL), and gas and microwave cooking (FLCO5, FLCO10, and FLMCO2). Vitamins, chlorophyll, minerals, phenolic compounds, and anti-nutrients were analyzed. All laboratory experiments adhered to procedures and guidelines. The pH dropped more significantly to <3.5 in a 3% salt-3% sugar brine solution with 1.328 ± 0.006 mg/100 g of lactic acid compared to its counterpart. Blanched leaves dried in 5 days, but unblanched leaves took 15 days. Fermented samples demonstrated a notable reduction in total chlorophyll concentration (0.0964 ± 0.075 mg/g) compared to other processing techniques. The nutritional and anti-nutritional composition of Justicia heterocarpa showed significant change (P < 0.05) depending on processing methods. The results indicated a significant loss of vitamin C in the fermented and ten-minute cooked samples, at 74.57% and 61.64%, respectively.Cooked FLMCO2 (107.4%, 11.29 ± 0.03 mg/100g) and FLCO5 (86.26%, 10.51 ± 0.02 mg/100g) exhibited more than a two-fold increase in beta-carotene compared to fresh leaves (3.67 mg/100g). In comparison to alternative processing procedures, samples cooked for 10 minutes exhibited significant mineral leaching, whereas unblanched direct shade drying preserved the highest mineral concentration. Fermented samples (532.83 ± 14.91 GAE/100 g) exhibited a 64.19% increase in total Phenolic compounds compared to fresh leaves (190.83 ± 14.91 GAE/100 g). Nonetheless, tannins increased by 68.1% (254.44 ± 7.45 GAE/100g) in the fermented samples. Samples exposed to extended cooking (17.8 ± 3.17 mg/100 g) and fermentation (40.28 ± 3.34 mg/100 g) exhibited the lowest levels of phytates. The oxalate concentration was significantly decreased in the cooked samples. Justicia heterocarpa may serve as a sustainable food supply in areas of Tanzania experiencing nutritional deficits.
Epidemiology of tuberculosis in inmates of selected central prisons in Tanzania
(Sokoine University of Agriculture, 2014) RUGAMBA,WILSON EMMANUEL
A cross sectional study was carried out to determine prevalence of tuberculosis (TB) among prison inmates and assessed risk factors contributing to the disease in five selected Central prisons namely; Butimba, Isanga, Ruanda, Ukonga and Segerea in Tanzania. The prevalence was established based on sputum smear microscopic examination for Acid Fast Bacilli (AFB). Questionnaires were used to gather information from prison inmates and prison staff about possible risk factors for TB spread in prisons. Due to the current association between HIV infection and TB epidemic, HIV screening was carried out by testing capillary blood adhering to the National algorithm whereby two serial rapid antibody tests namely Alere Determine and Uni-Gold were used. A total of 370 prisoners out of 8330 inmates were involved and the overall prevalence of TB was 3.8%. On commencement of the survey, 71 prisoners (0.85%, n=71; N=8330) from studied prisons were under anti TB treatment. The overall prevalence of HIV in studied Prisons was 5.4%. Il was also noted that overcrowding, poor ventilation, poor prison architecture, history of TB contact, HIV infection, smoking cigarettes, and limited knowledge on TB to prisoners were the risk factors for TB in prisons. The present study confirms the high prevalence of pulmonary tuberculosis in prison populations, thus suggest not only active transmission of the disease in the prison settings but also the need for executing urgent preventive measures.
Assessment of knowledge, attitudes and practices on breastfeeding among HIV infected mothers with infants in Kibaha town council
(Sokoine University of Agriculture, 2011) RWERAMIRA,MARGARETH CLEMENT
Knowledge, Attitudes and Practices (KAP) on breastfeeding among HIV-infected mothers are important in determining the health and nutritional status of their children. The HIV pandemic and the risk of mother-to-child transmission (MTCT) of HIV, especially through breastfeeding (BF) poses special difficulties to HIV-infected mothers, their infants and the community. This study was designed to assess KAP on breastfeeding among HIV-infected mothers having children aged 0-12 months living in Kibaha Town Council. A cross-sectional, descriptive study design was employed and convenient sampling procedure was used to select the respondents. Primary data were collected using structured questionnaire which were administered by face to face interview. Data analysis was done using Statistical Package for the Social Science (SPSS) 15.0 version computer software. The study findings revealed that there is limitation in terms of KAP on BF, complementation and infant feeding options among the HIV-infected mothers. Breastfeeding was chosen by majority of respondents (96%) compared to replacement feeding (6%). About 76% of mothers ceased to practice EBF before their infants were six months old due to fear of MTCT of HIV. The study also revealed that mothers’ level of education was significantly associated with their knowledge (p = 0.00403). Mixed feeding (63.6%) and nipple cracks (77.8%) were the most known factors by the respondents to increase the risk of MTCT of HIV. Breast conditions such as sore/cracked nipples; fear of stigma; lack of counselling and follow up from the health workers; and cultural beliefs such as BF by using one breast were observed as the constraints faced by the respondents. Counselling services on infant feeding options, regular follow to mothers and more training to the counsellors on BF and PMTCT of HIV need to be strengthened
Farmers' knowledge and traditional processing practices of pigeon peas (cajanus cajan) in rural areas in Lindi region Tanzania: a quantitative and qualitative mixed study
(Tanzania Journal of Agricultural Sciences, 2024) Tiisekwa, A.B; Chove,B.E; Mongi,R; Rybak, C; Stuetz, W.
Pigeon peas (Cajanus cajan) are an important protein source in many parts of tropical and sub-tropical regions of the world. However, their quality and availability may be affected by post- harvest handling and processing practices in use. In the present study, knowledge and practices of pigeon pea growers (PPG) in Lindi Region were evaluated with respect to harvesting, storage, processing and cooking preparation. A sample of 597 randomly selected PPG from two villages, were interviewed and 60 farmers participated in focus group discussions. Majority PPG (83.6%) harvested pigeon peas (PPs) by cutting and putting them in polyethylene sacks while 86.6% had knowledge on only one storage method. Also, majority of PPG (77%) lacked any processing knowledge on mentioned methods such as hulling and solar drying. Results also indicated 75.7% of PPG having no knowledge on cooking preparation methods out of which 94.5% had no knowledge on soaking, 89.6% on use of bicarbonate and 89.9% on methods to increase shelf life of PPs. Overall, 49.4% had little/limited knowledge on harvesting, storage, processing, and cooking preparation practices, with no significant gender difference. All PPG prepared stew using green or dry PPs. A sizeable proportion (45%) of PPG used dry PPs for stew preparation, after traditional hulling. The threshing of peas from pods was carried out manually. Traditional methods in the Lindi Region are laborious and time-consuming; resulting in poorly prepared products thus affecting the appearance of processed PPs. Training farmers on proper postharvest handling and processing can improve food security and market appeal.
Organophosphorus pesticide residues in tomatoes: a case of Mlali and Doma wards in Mvomero district, Morogoro
(Tanzania Journal of Agricultural Sciences, 2024) Wenaty, A; Mkojera,B
Extensive pesticide use poses a significant challenge to Tanzania's horticulture industry, particularly affecting the leading tomato producer, the Morogoro region. This study focused on assessing organophosphorus pesticide residues in tomatoes from Mlali and Doma divisions in the Mvomero district of Morogoro. A total of 40 samples were collected from both farms and markets for analysis, utilizing Gas Chromatography with Mass Spectrometry (GC-MS) for extract analysis. Statistical Analysis Software (SAS) Version 9.1 was employed for data analysis. The study identified six organophosphorus pesticides, with concentrations in the following order: pirimiphos methyl > diazinon > fenitrothion > dimethoate > profenofos > chlorpyrifos. Pirimiphos methyl levels ranged from 3.32±0.03 to 9.53±0.05 μg/kg in Mlali samples and 0.20±0.01 to 6.33±0.03 μg/ kg in Doma samples. Chlorpyrifos was detected in the lowest concentrations across all samples. Interestingly, higher pesticide levels were found in market samples compared to those from farms, suggesting potential misuse post-harvest and during distribution. This misuse could have severe consequences for tomato consumers, including both carcinogenic and non-carcinogenic effects. The study underscores the importance of educating farmers on the proper use of pesticides and the potential adverse effects resulting from their misuse. Addressing this issue is crucial for ensuring the safety of tomatoes in the market and protecting consumers from harmful effects associated with pesticide residues.
Tomato post-harvest losses as influenced by improper handling facilities in Morogoro, Tanzania
(AJOL, 2023) Mwankemwa, L.S.; Silayo ,V.C.; Lazaro, E.L; Mrema G.C.
The losses on perishables have been a challenge for so long in developing countries, the current status is critical and its control for small-scale farmers and retailers has not been adequately addressed. The aim of this study was to generate information on tomato handling practices and losses for small-scale farmers and retailers in six selected areas in Morogoro region, Tanzania. A need assessment survey was conducted to help gather information on tomato postharvest handling and practices for the purpose of preparing possible mitigation actions. Sixty respondents with at least 3 years of farming or retailing tomatoes were purposively selected through the help of the extension officer and market leaders to represent part of the tomatoes’ handling chain. The SPSS version 16 statistics software was used for data analysis using descriptive statistics. The findings obtained showed that farmers were not using any storage facilities for tomatoes while retailers used inferior handling facilities and some did not use any storage facilities ultimately losing most of their tomatoes. This study found that tomato post-harvest losses (PHLs) were 29.7% at the farmers’ level and 18.4% at the small-scale retailers’ level during handling and marketing. Besides 60-80% of the farmers and 30-80% of retailers were unaware of the existence of Evaporative cooling structures (ECSs) to avert tomato PHLs. However, 60-80% of all respondents indicated the desire to have ECSs used to improve their tomato business. This prompted the need to have ECSs introduced in order to extend the shelf life of tomatoes while maintaining their quality and hence reducing PHLs.
Development of natural liquid and powdered meat tenderizer based on papaya peel, ginger and garlic
(Science Publishing Group, 2024-04-12) Issa-Zacharia Abdulsudi; Muhimbula Happiness Samuel; Bikuba Anastazia Niyonkulu; Mato Joachim Dotto
Recently, the application of exogenous enzymes for meat tenderization has turned the attention of food technologists and meat scientists. This research investigates the synergistic impact of natural tenderizers derived from the combination of papaya peels (P), ginger (G), and garlic (Ga) on the sensory attributes of goat meat such as color, aroma, taste, tenderness and overall acceptability. The tenderizers were formulated in different concentration ratios of 3:2:1 in both liquid and powdered form. The sensory quality parameters for all tenderized goat meat samples under observation including the control, were evaluated by 60 semi-trained panelists using a five-point hedonic scale. The effect of tenderizers was compared to the control which was devoid of tenderizing ingredients. Tenderness was greatly improved (p<0.05) by tenderizer P:G:Ga (3:2:1) in both liquid and powder forms at 45- and 90- minutes of tenderization. Alternatively, liquid and powdered Ga:G:P (3:2:1) were highly significantly rated (p<0.05) in taste compared to all other tenderizer formulations for 45- and 90-minute tenderization. From the samples tested, the control sample in both setups was the least rated in all sensory attributes, except for color in powdered tenderization. Generally, liquid and powdered P:G:Ga (3:2:1) and Ga:P:G (3:2:1) tenderizers received significantly higher (p<0.05) overall acceptability scores than G:G:aP (3:2:1) and the control sample. While liquid tenderizers mostly performed better compared to powdered tenderizers for all sample combinations, there was a significant improvement (p<0.05) in tenderness when both liquid and powdered tenderizers were used for 90 minutes compared to 45-minute marination. This suggests that, the longer the tenderization time, the greater the effect on tenderness. These findings underscore the importance of natural tenderizers in enhancing consumer satisfaction with meat products,
Assessment of compliance with good agricultural practices in pig farming in Mpwapwa and Mbulu districts, Tanzania
(Taylor & Francis Group, 2023-07-14) Nonga, Cosmas; Zacharia, Issa; Mkupasi, Ernatus; Ngowi, Helena
A cross-sectional study was conducted between February and May 2022 to explore the pig farming practices and assess their compliance with Good Agricultural Practices (GAPs) and their associated constraints in Mpwapwa and Mbulu districts. A total of 136 pig farmers were randomly chosen from purposively selected wards for interview using a structured questionnaire. The study revealed that 71.3% of all pig farmers were aware of GAPs on pig farming, but only 19.8% of the pig farmers complied with the stipulated GAPs. About 81.6% of the respondents had poor piggery hygiene and 76.5% had poor piggery conditions. Pig farmers reported the cost of feeds (83.8%) and veterinary services (81.6%) to be the hindrance to compliance with GAPs. It was concluded that pig farmers are aware of GAPs but not all implement them. Limited availability and high costs of pig feeds and veterinary services are among the factors limiting the full implemantation of GAP in pig farming in the Mpwapwa and Mbulu districts. Therefore, there is a need for the Ministry of Livestock and Fisheries Development and private investors to collaborate to ensure accessibility to Agro-vet services in rural areas with minimal cost. A positive effect could also result from encouraging pig farmers to use locally available ingredients to compose pig feeds.
Erosion hazard assessment in the upper Ewaso Ng’iro basin of Kenya: application of gis, usle and eurosem
(Sokoine University of Agriculture, 1999) Mati Bancy Mbura
A methodology was developed for assessing soil erosion hazard in the Upper Ewaso Ng’iro basin of Kenya, using Geographic Information Systems (GIS), the Universal Soil Loss Equation (USLE) and the European Soil Erosion Model (EUROSEM). The USLE was used in a GIS environment by creating thematic maps of R, K, L, S, C and P and then calculating soil loss by raster-grid modelling with Arc/Info GRID. The rainfall erosivity factor (R) was derived from relationships between rainfall amount and erosivity using erosion plot data from within the catchment. The nature of the relationship was found to be a function of agi o-climatic zones of the region. Mean annual erosivities ranged from 145 to 990 J m'2 hr'1. For a given amount of rainfall, erosivity was higher in zone IV than in the wetter zones 11-111. The soil erodibility factor (K) was estimated using the USLE nomograph and data from laboratory analysis of field samples collected from representative major soil mapping units. The K-values were low to medium, ranging from 0.10 to 0.25 over 84 percent of the basin. The topographic factor (LS) was obtained by creating Digital Elevation Models (DEMs) of the basin with TOPOGRIDTOOL of Arc/Info. These were then used to determine the slope steepness and length factor values, calculated with raster-grid modelling. Although DEMs proved a useful tool, maximum values of both steepness and length had to be set in this reconnaissance study to achieve reasonable results. A finer resolution of input data and a smaller grid cell size are needed for accurate determination. The cover and management factors (C) were obtained by determining the land cover types within the basin using remotely sensed data (SPOT 1 colour composite prints) and ground truthing studies. The factor values were estimated from USLE guide tables and measurements of cover from plots and test sites. Some 70 percent of the basin is covered by rangelands. The conservation practice (P) factor values were estimated from USLE guide tables and then applied to areas where soil conservation had been introduced /?. M. Mali PM > Thesis 1999 Silsoe College Cranfield .■Ihstract •'university II according to maps obtained from the Ministry of Agriculture. The USLE was validated using data from erosion plots. A value of R2 = 0.645 was obtained between predicted and measured values but the standard error was rather high (e = 5.745 t ha'1 yr'1). Using an annual soil loss of 9.0 t ha'1 yr'1 as tolerance level, some 36 percent of the basin was found to experience unacceptably high erosion rates. Most of this area was communal grazing land and cropland where soil conservation measures had not been applied. A critical land cover type within the grazing land is shrubland, where vegetation cover is less than 40 percent and high erosion risk was predicted and confirmed by field surveys. EUROSEM could not be integrated within a GIS in the time available for research. It was therefore simulated outside GIS environment, where it was applied to Embori and Mukogodo plot data using separate data sets for calibration and validation. Calibration was used to obtain input parameters for saturated hydraulic conductivity, cohesion and Manning’s roughness coefficients. Validation gave correlation coefficients of 0.907 and 0.840 for predictions of storm runoff and soil loss respectively at Embori; the corresponding values for bare soil plots at Mukogodo were 0.895 and 0.577. However, EUROSEM predicted runoff poorly (R2 = 0.570) and failed to predict soil loss at all the vegetated plots at Mukogodo. The model was applied to simulated vegetation covers of barley, maize, grass and forest for a 36.7 mm rainstorm at Embori. The simulated soil losses showed an exponential decrease with increasing cover. At a threshold cover of 70 percent, soil loss diminished to zero under grass and forest and decreased to a minimum value under barley and maize. These results support the USLE simulations, which showed that areas with more than 70 percent cover (such as forest) had a low erosion hazard, even with steep slopes and high rainfall erosivities. This research has demonstrated that GIS can be used with the USLE to assess and quantify erosion hazard, giving results that can be used for conservation planning. EUROSEM can be applied successfully to bare soil and cropland, but application to other land covers requires further investigation. Land cover and topography are the main factors controlling the spatial distribution of soil loss in the Upper Ewaso Ng’iro basin. Future conservation activities should be concentrated on the rangelands.
The impacts of frozen storage and fatty acid oxidation on silver carp myofibrillar protein functionality
(Jiangnan University, Wuxi, JiangsuProvince, P.R., 2006) Mlyuka, Erasto
Silver carp (Hypophthalmichthys molitrix) is a freshwater species living in temperate conditions (6-28 °C) and its natural distribution is in Asia. It is generally cultured and marketed locally alive or fresh in most of the producing countries. China is the largest producer of silver carp in the world; however, its market price is relatively low compared to most other species, normally costs 8-10Yuan/kg. In order to keep the product longer and further extend the markets instead ofjust consuming it fresh, processing technologies for adding value and frozen storage are of significantly important for this fish species. In this thesis, the report is mainly focused on the study done on isolation of myofibrillar protein from silver carp; exposing the isolated myofibrillar protein to oxidative environment simulated using an iron oxidation model system to mimic the oxidative stress during processing and frozen storage. Also the impacts of the iron oxidation model system, fatty acid oxidation and frozen storage on protein functionality of silver carp myofibrillar protein isolate were evaluated. Oxidative damage to silver carp myofibrillar proteins isolate (MPI) was investigated by measuring changes in physico-chemical, and functional properties after exposure to iron-catalyzed oxidation system (IOS). Iron oxidized MPI exhibited an increase in carbonyl content and dityrosine, which were significant and negatively correlated with protein solubility (PS) (r=0.85), (r=0.80) and gel strength (GS) (r=0.95), (0.93), respectively, however the decrease in total thiol group content was significantly and positively correlated with PS (r=0.77) and GS (r=0.89). These led to significant changes (P<0.05) observed in the protein and functional properties of oxidized MPI. Sodium dodecyl sulfatepolyacrylamide gel electrophoresis demonstrated that IOS resulted in a major loss of myosin and actin associated with formation of protein polymers as supported by gel-permeation chromatography (GPC) results. The total fat content of silver carp MPI was 0.6%, it is mainly composed of unsaturated fatty acids of which about 34% constituted by eicosapentaenoic acid, ( 2O:5co-3), docosahexaenoic acid, ( 22:6co-3), and linolenic, ( 18: 3m-3) as the main co-3 poly-unsaturated fatty acids (PUFAs) as well as linoleic acid, (18:2co-6) and arachidonic acid, (20:4co-6), the main co- 6 PUFAs in fish , unfortunately PUFAs are prone to oxidation producing reactive oxygen species capable of modifying protein structure. This study suggests that the decreased functionality of proteins in muscle foods exposed to an oxidative environment could be due to chemical and physical changes resulting from oxidation reactions. It was found that silver carp myofibrillar protein is susceptible to an iron-catalyzed oxidation causing a significant loss of its functionality, thus a study was carried out to iii Jianenan University, M.Sc Thesis, 2010 Abstract determine the susceptibility of silver carp protein to natural oxidants (fatty acids or fatty acids oxidation products) in frozen storage with respect to its functionality. Frozen stored myofibrillar protein isolate with 0.6M NaCl or myofibrillar protein isolated from previous frozen stored whole fish and fish mince of silver carp at -18°C for 90 days were assessed for protein and lipid oxidation with regard to protein functionality. The addition of sodium chloride to 0.6M at pH6.5 improved protein functionality especially water holding capacity of frozen stored myofibrillar protein isolate from 5.3 to 6.4mL/g MP1 after 90 days of frozen storage. However, the differential scanning calorimeter results showed that, sodium chloride significantly increased thermal susceptibility of myosin from 48.12 to 46.40°C with 0.1M NaCl and 0.6M NaCl frozen stored for 90 days, respectively. Whole fish frozen storage was more susceptible to oxidation compared to fish mince and myofibrillar protein isolate due to their different lipid content. On contrary, myofibrillar isolated from frozen whole fish showed significant changes in protein functionality may be due to great loss of amino acid such as cysteine, lysine, histidine and methionine during frozen storage. On the other hand investigation was done on stabilization and oxidation protection of silver carp MP1 stored at -18 °C, 90 days and composed of MPI, 8% cryoprotectants (4% sucrose and 4% sorbitol) with or without antioxidants (0.2% ascorbate, 0.2% a- tocopherol, or their combination) and packed in a polyethylene bag, sealed under air. MPI without cryoprotectants and antioxidants was the control. Compared with the control, cryoprotectants increased PS (protein solubility), WHC (water holding capacity), OHC (oil holding capacity), EC (emulsification capacity) and GS (gel strength), also, the cryoprotectants and/or antioxidants decreased MPI oxidation susceptibility as well as susceptibility of myosin to thermal denaturation. After 30 days of frozen storage, there were no significant differences ((P>0.05) of storage time on alteration of protein functionality and actin susceptibility to thermal denaturation between cryoprotectants and the control. Antioxidants minimized oxidation effects on MPI frozen storage. Therefore, the present study reveals that, improvement in the functional properties of silver carp MPI were greatly influenced by cryoprotectants and antioxidants, this reflect a great role played by sucrose/ sorbitol and antioxidants in protecting native protein structure to a greater extent owing to impact of frozen storage and oxidation respectively.
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
Quality evaluation of fresh selected orange fleshed sweet potatoes in lake zone of Tanzania
(Science Publishing Group, 2023) Chuwa,Caresma; Zacharia,Abdulsudi Issa
Vitamin A Deficiency (VAD) is a public health problem in developing countries in children below five years. Orange Fleshed Sweet Potatoes (OFSP) are rich in β-carotene a pre-cassor for vitamin A. Being a cheap and affordable source, can be utilized by incorporating in staple foods to combat VAD in developing countries. OFSP fresh roots (Ejumla, Jewel and Carrot dar) were collected from Ukerewe and Misungwi District, Mwanza region for quality evaluation. The findings of the study indicated that there was considerable variance in the nutrient content across the several types of OFSP that were tested. Among the varieties that were chosen for analysis, it was found that Jewel had the maximum quantity of β-carotene (113,565 ± 1.45 μg/100 g), whilst Carrot dar had the lowest concentration (5,165 ± 3.38 μg/100 g). In addition to β-carotene, the aforementioned varieties of OFSP exhibited a diverse array of nutrients, including protein (3.82% - 8.86%), fat (0.32% - 0.51%), fibre (1.83% - 3.15%), carbohydrate (87.05% - 92.60%), ash (0.86% - 1.09%), ascorbic acid (15.04 mg/100 g - 17.27 mg/100 g), and energy content (385.19 Kcal/100 g - 392.92 Kcal/100 g). Several minerals were discovered in the selected OFSP varieties. Jewel exhibits a high content of essential minerals such as calcium (44.30 mg/100g), iron (1.34 mg/100g), zinc (0.35 mg/100g), and potassium (317.12 mg/100g). Conversely, Ejumla is characterized by its notable sodium (112 mg/100g) and magnesium (2.73 mg/100g) content, making it a valuable source of these minerals. Based on the findings, it can be concluded that OFSP possesses a high concentration of essential nutrients that play a crucial role in addressing both macro and micro-nutrient deficiencies in developing countries. Hence, individuals should integrate Orange Fleshed Sweet Potatoes into their primary food sources as a means of enhancing the overall nutritional value.

Browse

Recent Submissions