School of Engineering and Technology
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Item Acceptability of soup powders made from selected traditional leafy vegetables grown in Lindi, Tanzania(2021) Abdallah, A.; Chove, L. M.A study was conducted to assess the acceptability of soup formulated from traditional leafy vegetables (TLVs) grown in Lindi, Tanzania. Three TLVs, Amaranth hybrids known as amaranthus leaves (AML), Manihortesculenta known as cassava leaves (CAL) and Ipomeabatatas known as sweet potatoes leaves (SPL) which had been optimized for Iron content, were used to prepare 4 vegetable soup formulations (F1– 60.0:7.5:22.5); (F2 –70.0:5.0:15.0); (F3 –80.0:2.5:7.5) and (F4 –40.0:10.0:40.0) respectively. Descriptive sensory analysis was performed by10 trained panelists who used 5 descriptors to quantitatively describe the sensory characteristics of four soup formulations. Thirty consumers assessed the degree of liking of products’ sensory attributes using a 7-point hedonic scale. External preference mapping was performed by relating sensory data with hedonic responses. Mean intensity ratings of descriptive attributes of the soup showed that F1, F2 and F3had significantly higher(p<0.05) mean intensity scores in colour, aroma, and mouth feel than F4. The consumer study showed that, with exception of mouth feel, consumers showed significant differences (p<0.05) between samples in colour, aroma, taste and overall acceptability. It was thus concluded thatF1 was the most liked by consumers due to colour, aroma and mouth feel followed by F2 and then F3 and finally F4. Furthermore, the preference mapping results showed that colour, aroma and mouth feel attributes were the main drivers for positive consumer preference for vegetable soup. Thus, selection and processing of vegetables, which retain these attributes, is of greater importance for consumer acceptability and hence increased utilization for consumer’s health and well-being.Item Application of slightly acidic electrolyzed water as a potential sanitizer in the food industry(Hindawi, 2024-02-29) Issa-Zacharia,AbdulsudiTe food industry has extensively explored postharvest microbial control, seeking viable technologies to ensure food safety. Although numerous chlorine-based commercial sanitizers serve this purpose, many are plagued by constraints such as instability and diminished disinfectant efcacy. Tese issues arise from exposure to organic matter in wash water, light, or air. As an innovative and promising alternative, slightly acidic electrolyzed water (SAEW) has emerged, captivating attention for its robust sterilization potential and eco-friendliness in agricultural and food sectors. SAEW generated via electrolysis of a diluted hydrochloric acid (HCl) solution with concentrations ranging from 2 to 6% or aqueous solution of sodium chloride (NaCl) in a nonmembrane electrolytic chamber is reported to possess equivalent antimicrobial properties as strong acidic electrolyzed water (StAEW). In contrast to traditional chlorine sanitizers, SAEW leaves less chlorine residue on sanitized foods such fresh-cut fruit and vegetables, meat, poultry, and aquatic products due to its low available chlorine concentration (ACC). Its near neutral pH of 5 to 6.5 not only renders it environmentally benign but also mitigates the production of chlorine gas, a contrast to low pH conditions seen in StAEW generation. Te bactericidal efect of SAEW against various strains of foodborne pathogens is widely believed and accepted to be due to the combined action of high oxidation-reduction-potential (ORP) reactions and undissociated hypochlorite/ hypochlorous acid (HOCl). Consequently, a burgeoning interest surrounds the potential of SAEW for sanitation in the food industry, ofering an alternative to address shortcomings in sodium hypochlorite solutions and even StAEW. It has been hy- pothesized from a number of studies that SAEW treatment can increase the quality and nutritional value of harvested fruits, which in turn may enhance their ability to be stored. Terefore, SAEW is not only a promising sanitizer in the food industry but also has the potential to be an efcient strategy for encouraging the accumulation of bioactive chemicals in plants, especially if it is used extensively. Tis review encapsulates the latest insights concerning SAEW, encompassing its antimicrobial efectiveness, san- itization mechanism, advantages vis-à-vis other sanitizers, and plausible applications across the food industryItem Assessing potential land and surface water resources available and suitable for irrigated agriculture in the wami sub-basin Morogoro(Sokoine University of Agriculture, 2021) Malekela, Charles JohnAssessing potential land and water resources suitable for surface irrigation is essential for proper planning of their utilization types. The assessment has a great role in satisfying subsistence requirements, increasing agricultural production and hence reducing poverty. Despite efforts made by various stakeholders to improve agricultural productivity by increasing irrigated areas, Tanzania is still facing a daunting task of reaching the one million hectare target of irrigated area. This indicates that land and water resources are not presently effectively utilized. This study was initiated with the objective of assessing the land and water resources suitable for irrigated agriculture along with the extent of small-scale irrigation in the Wami sub-basin. Geographical Information System (GIS) based on Multi Criteria Decision Analysis (MCDA) was used along with various spatial tools including a model builder which was used to create geo-referenced maps of land and water resources. Ten layers (irrigation suitability factors) were used in the analysis for identification of potential land suitable for irrigated agriculture. Results indicate that, based on the suitability factors about 841.39 km 2 (3.11% of the total area), is highly suitable for surface irrigation, about 18,244.41 km 2 (67.51%), is moderately suitable and 7939.87 km 2 (29.38%), is marginally suitable for surface irrigation. Furthermore, results shows that the extent of small-scale irrigation is about 1958.87 km 2 . Moreover, results indicates that, approximately 1958 km 2 of land assumed to represent the extent of small- scale irrigated areas in Morogoro region including Dakawa and Mvomero in particular. As such, the exploration of various resources as observed in this study, including land, soil and water was well demonstrated by the integration of GIS-Based Multi Criteria Decision Analysis (MCDA), and the weighted overlay technique for land suitability analysis.Item Assessment of bacterial contamination and associated risk factors in pork slaughtered and marketed in urban Tanzania(Tanzania Journal of Health Research, 2023-10) Nonga Cosmas; Zacharia Issa; Mkupasi Ernatus; Ngowi HelenaIntroduction: In Tanzania, pork consumption is increasing and become popular in urban areas creating a good market for pigs raised in rural areas. However, little is known regarding the microbial safety of the marketed pork in the country. This study assessed the level of bacterial contamination and contributing factors in pork slaughtered and sold in Arusha, Dar es Salaam and Dodoma Tanzania through Total Viable count, Coliform count, Escherichia coli and Staphylococcus aureus count. Methods: A cross-section study was conducted and a total of 90 pork samples were collected from pig slaughter facilities, pork centres and butcheries. Standard methods for microbial analysis in food products (ISO 7218:2007(E)) were used. Results: It was revealed that all (100%) pork samples had bacteria contamination with an overall mean for total viable count of 5.93±1.50 log CFU/g, and coliform forming unit of 4.30±1.14 log CFU/g. Over 92.2% of the pork samples were contaminated by E.coli with a mean count of 3.12±1.33 and S. aureus was isolated in more than 84.4% with a mean count of 2.71±1.34 log CFU/g. The mean values were higher than the limit set by Tanzania Standard (TBS/AFDC 22 (5266) P3). In addition, 79.4% of the pork slaughter facilities and selling points surveyed had poor hygiene and lacked safety and quality control measures. Conclusion: Thus, it may be deduced that the pork carcasses assessed were of poor microbiological quality posing a health risk to pork consumers. To minimize public health risks, food control authorities should ensure effective enforcement of policies and regulations in controlling pig slaughtering and pork marketing in the country. Also, education on hygienic practices for all stakeholders along the pork value chain should be provided.Item Assessment of irrigation systems’ performance and sustainability in Burundi(Sokoine University of Agriculture, 2022) Manirakiza, ProsperIrrigated agriculture has a crucial role to play in enhancing food security; hence, irrigation expansion would significantly increase agricultural production, improving household income and reduce food insecurity and poverty levels among smallholder farmers. However, majority of irrigation schemes developed in Burundi have performed below their potential. Evaluation of the performance of an irrigation schemes is essential in knowing whether water availability meets or exceeds demand. In Burundi, these evaluations are limited. This study aimed to assess the irrigation systems’ performance and sustainability in Burundi with a case study of Kidwebezi Irrigation Scheme. Specifically, this study intended (i) to evaluate the performance of the irrigation structures, (ii) to assess the water delivery performance using technical indicators and (iii) framers’ knowledge and to assess the effect of Irrigators’ Association on the performance of Kidwebezi Irrigation scheme with the target of evaluating the existing operation rules and proposing alternative options for further improvement. In this study, a float method was used for determining the flow rate. The CROPWAT Penman-Monteith method was used to determine the reference crop evapotranspiration, the combination of Food and Agriculture Organization (FAO) CROPWAT 8.0 simulation software and the CLIMWAT 2.0 tool was used to calculate the crop water requirement (CWR) of the paddy. Field observations (state of a structure) and physical work were used to evaluate the performance of the irrigation structures. Based on the technical performance indicators such as efficiency, adequacy, dependability, equity and water productivity, the performance of water delivery was assessed. A social economic survey (farmer interviews, focus group discussions and key informants) was undertaken to assess financial self-sufficiency, fee collection and relative water costs of the scheme. Results for the performance evaluation of irrigation structures showed that 84.15%were still functioning. On the physical condition part, the findings showed that the intake was working at 80%; canals network was operational at 80% while command area development was functioning at 88%. For the conveyance efficiency, the results indicate that 82.48%, 80.40% and 66.38% of water conveyed reached the destined farm for lined main canal, lined secondary canal and unlined secondary canal, respectively. The total net irrigation and total gross irrigation were 342.2 mm and 760.4 mm. The study results showed that the irrigation system was good in terms of adequacy and poor in terms of efficiency while it was fair to both dependability and equity. Moreover, the results for the assessment of effect of Irrigators’ Association with regard to financial viability and sustainability of the scheme were found to be encouraging. The results showed that the effectiveness of fee collection (EFC) was 87.77%, the financial self-sufficiency (FSS) was 3.11 with an average relative water cost of 0.05 and 97.75% of the scheme were still irrigated. The results from farmer interviews, focus group discussions and key informant showed that the uncontrolled paddy farming expansion, lack of updated irrigation knowledge and technologies and low efficiency on water use are the main causes of low yields of paddy in the Kidwebezi Irrigation Scheme.Item 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 NyabhigesoThe 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.Item Autonomous navigation of a center-articulated and Hydrostatic transmission rover using a modified Pure pursuit algorithm in a cotton field(MDPI, 2020-08-07) Kadeghe, Fue; Wesley, Porter; Edward, Barnes; Changying, Li; Glen, RainsThis study proposes an algorithm that controls an autonomous, multi-purpose, center-articulated hydrostatic transmission rover to navigate along crop rows. This multi-purpose rover (MPR) is being developed to harvest undefoliated cotton to expand the harvest window to up to 50 days. The rover would harvest cotton in teams by performing several passes as the bolls become ready to harvest. We propose that a small robot could make cotton production more profitable for farmers and more accessible to owners of smaller plots of land who cannot afford large tractors and harvesting equipment. The rover was localized with a low-cost Real-Time Kinematic Global Navigation Satellite System (RTK-GNSS), encoders, and Inertial Measurement Unit (IMU)s for heading. Robot Operating System (ROS)-based software was developed to harness the sensor information, localize the rover, and execute path following controls. To test the localization and modified pure-pursuit path-following controls, first, GNSS waypoints were obtained by manually steering the rover over the rows followed by the rover autonomously driving over the rows. The results showed that the robot achieved a mean absolute error (MAE) of 0.04 m, 0.06 m, and 0.09 m for the first, second and third passes of the experiment, respectively. The robot achieved an MAE of 0.06 m. When turning at the end of the row, the MAE from the RTK-GNSS-generated path was 0.24 m. The turning errors were acceptable for the open field at the end of the row. Errors while driving down the row did damage the plants by moving close to the plants’ stems, and these errors likely would not impede operations designed for the MPR. Therefore, the designed rover and control algorithms are good and can be used for cotton harvesting operations.Item 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 HamadMaize (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.Item Bushmeat consumption in Africa: a microbiological safety challenge?(Asian Food Science Journal, 2023-09-12) Ahouanse Gwladys Gloria Amen; Issa-Zacharia Abdulsudi; Majaliwa NuriaObjective: This review analyzed the microbiological safety of bushmeat consumed in Africa over the past decades. Methodology: Previous Studies mainly focused on large animals like antelopes and smaller ones like grasscutter. Most microbes studied were similar to those in domestic animal meat, except for rare pathogens such as Salmonella spp, E.coli. Sampling, experiments, and microbe prevalence varied among studies. Results: All studies confirmed the presence of zoonotic pathogens dangerous to human beings. Therefore, more investigations are needed, especially for the chronic and severe cases of pathogens, since only few studies have addressed the bushmeat's microbiological safety in Africa. Conclusion: Efforts should be made to improve bushmeat safety and public health in Africa. New policies and public regulations must be developed and implemented to ensure hygienic and legal bushmeat production in Africa.Item Center-articulated hydrostatic cotton harvesting Rover using visual-servoing control and a finite state machine(MDPI, 2020-07-30) Kadeghe, Fue; Wesley, Porter; Edward, Barnes; Changying, Li; Glen, RainsMultiple small rovers can repeatedly pick cotton as bolls begin to open until the end of the season. Several of these rovers can move between rows of cotton, and when bolls are detected, use a manipulator to pick the bolls. To develop such a multi-agent cotton-harvesting system, each cotton-harvesting rover would need to accomplish three motions: the rover must move forward/backward, turn left/right, and the robotic manipulator must move to harvest cotton bolls. Controlling these actions can involve several complex states and transitions. However, using the robot operating system (ROS)-independent finite state machine (SMACH), adaptive and optimal control can be achieved. SMACH provides task level capability for deploying multiple tasks to the rover and manipulator. In this study, a center-articulated hydrostatic cotton-harvesting rover, using a stereo camera to locate end-effector and pick cotton bolls, was developed. The robot harvested the bolls by using a 2D manipulator that moves linearly horizontally and vertically perpendicular to the direction of the rover’s movement. We demonstrate preliminary results in an environment simulating direct sunlight, as well as in an actual cotton field. This study contributes to cotton engineering by presenting a robotic system that operates in the real field. The designed robot demonstrates that it is possible to use a Cartesian manipulator for the robotic harvesting of cotton; however, to reach commercial viability, the speed of harvest and successful removal of bolls (Action Success Ratio (ASR)) must be improved.Item Chemical quality of stream and borehole water used by selected communities in Lushoto district, Tanzania(An International Journal of Basic and Applied Research, 2020) Hadija, A.; Chove, L.The chemical quality of water in two streams and three boreholes from Sunga and Mbaru wards in Lushoto, Tanzania was investigated. Water was collected at three locations along the stream, including forest areas, populated area with agricultural activities and less populated areas with agricultural activities. Borehole’s water was collected from three boreholes found in each ward and analyzed for pH, hardness, BOD, phosphates, nitrates by standard methods. Nested design was applied. Data obtained was analyzed by R-Software for ANOVA. Means were separated by Tukey‘s honest at p<0.05. Significant differences (p<0.05) in all chemical parameters (pH: 6.92- 7.34; Hardness; 23.88+64.43;Nitrite 1.73 -19.80; Phosphate 0.58-3.90; Ammonia 0.02-0.08; Lead -0.001-0.002) were observed in locations within the streams except arsenic. DDT was not detected. With the exception of phosphate in both streams, all water samples tested met TZS (2016) standards and WHO (2011) guidelines. This implies that stream water is considered unsafe for use since it exceeded the maximum phosphate limit by TZS (2016). All parameters tested in borehole water met the requirements for both standards except pH and ammonia which exceeded the WHO water guideline. It is recommended that the communities be educated on the best practices to keep water sources safe.Item Compliance by SMEs to existing Tanzania standards with respect escherichia coli and staphylococcus aureus in cultured milk: a case of Dar es salaam, Tanzania(An International Journal of Basic and Applied Research, 2021) Samwel, J.; Chove, L. M.Small and medium enterprises are important for economic growth not only in Tanzania but all over the world. Most of them are informal, without official registration. However, they provide tremendous contribution to food security, nutrition, income generation and poverty reduction in the country. Therefore, upgrading and modernization of Small and Medium Enterprises (SMEs) to ensure food security, safety and quality of food has becomes one of the priorities of Tanzania development visions of 2025, which is the blueprint of structural economic transformation of the country. To help achieve this, the present study was conducted to assess the safety of cultured milk. A total of 33 cultured milk samples were collected from 11 SMEs which were analyzed in triplicate to make 99. Two microorganisms, Escherichia coli and Staphylococcus aureus were analysed in cultured milk. Results were compared against the existing Tanzania standards. The isolates had an overall mean of 2.02 × 102 ± 1.73 × 102CFU/g, 1.91×102 ± 1.85 ×102CFU/g respectively for E. coli and S. aureusc count. The results obtained were higher than the limits set by the Tanzanian Standard (TZS1625:2013). It may thus be concluded that sampled cultured milk was of poor microbial quality and hence not safe for consumption. Poor hygienic practices during milk handling pose a high risk to cultured milk and render it unsafe for human consumption.Item Deep learning based Real-time GPU-accelerated tracking and counting of cotton bolls under field conditions using a moving camera(2018 ASABE Annual International Meeting, 2018-08) Fue, Kadeghe G.; Porter, Wesley; Rains, GlenRobotic harvesting involves navigation and environmental perception as first operations before harvesting of the bolls can commence. Navigation is the distance required for a harvester’s arm to reach the cotton boll while perception is the position of the boll relative to surrounding environment. These two operations give a 3D position of the cotton boll for picking and can only be achieved by detection and tracking of the cotton bolls in real-time. It means detection, tracking and counting of cotton bolls using a moving camera allows the robotic machine to harvest easily. GPU-accelerated deep neural networks were used to train the convolution networks for detection of cotton bolls. It was achieved by using pretrained tiny yolo weights and DarkFlow, a framework which translates YOLOv2 darknet neural networks to TensorFlow. A method to connect tracklets using vectors that are predicted using Lucas-Kanade algorithm and optimized using robust L-estimators and homography transformation is proposed. The system was tested in defoliated cotton plants during the spring of 2018. Using three video treatments, the counting performance accuracy was around 93% with standard deviation 6%. The system average processing speed was 21 fps in desktop computer and 3.9 fps in embedded system. Detection of the system achieved an accuracy and sensitivity of 93% while precision was 99.9% and F1 score was 1. The Tukey’s test showed that the system accuracy and sensitivity was the same when the plants were rearranged. This performance is crucial for real-time robot decisions that also measure yield while harvesting.Item Design of the improved evaporative cooling structure for storage of tomatoes in morogoro(Sokoine university of agriculture, 2022) Mwankemwa, Leonard SaimonIn most developing countries, smallholder farmers face several challenges while embarking on their farming for agriculture crop production. The challenges are serious during post-harvesting processes. The phenomenon is evident in sub-Saharan countries, Tanzania inclusive. Tanzania’s economy is agriculturally based which contributes 26.7% of its GDP and it employs over 80% of the population. As such any efforts geared to eradicate poverty and improve livelihoods should focus on the agriculture (horticulture subsector) which is characterized by small scale subsistent farming, low productivity, and huge post-harvest losses. These huge losses can be attributed to a lack of appropriate post- harvest processing techniques, low awareness, on the part of good harvesting and packaging practices or techniques and lack of storage facilities. Morogoro smallholder farmers of tomatoes are not spared from this phenomenon. Several storage technologies for curbing tomato post-harvest losses have been introduced to smallholder farmers. Some technologies have shown promising results. However, more investigation of the technology’s effectiveness is needed. This study aimed to design an evaporative cooling structure for the storage of tomatoes. A need assessment survey was conducted to help generate information on tomato handling practices and losses for small scale farmers and retailers in six selected areas in the Morogoro region. 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 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. The majority of the respondents showed a desire to possess evaporative coolers to reduce tomato PHLs. In this context, the improved wind operated passive evaporative cooling (IWOPEC) storage structure for tomatoes was designed and fabricated, and its performance was evaluated against other storage conditions. A randomized complete block design (RCBD) was used. The storage environment conditions considered were ambient (AT), cold room (CR), and IWOPEC structure. The results on the effects of temperature and relative humidity (RH) were significantly different (p<0.05) under the studied storage environments. Total soluble solids and percentage weight loss significantly increased (p<0.05) for all studied environmental conditions, whereas firmness and titratable acid significantly decreased (p<0.05) in response to storage time and environmental conditions. The IWOPEC structure reduced temperature, increased RH and gave peak and daily average cooling efficiency of 84.89% and 61.67%, respectively. The result of the benefit-cost ratio (BCR) was 2.51 shows using the IWOPEC structure for the storage of fresh ripened tomatoes is viable. In areas with high PHLs under AT, using the IWOPEC structure to improve the shelf life of tomatoes is economically feasible. Improvement of the IWOPEC structure by having water boot sump and a water pump to increase the cooling efficiency of the storage atmosphere is recommended.Item Detection of proteolysis in high temperatures treated milk by reverse phase high performance liquid chromatography (RP-HPLC)(Academic Journals, 2014-02) Chove Lucy M.; Grandison S. Alistair; Lewis Michael J.; Issa- Zacharia AbdulsudiProteolysis of UHT milk during storage is one of the problems affecting the dairy industry worldwide. Native enzymes have been implicated as being the main cause of spoilage of such milk. In the current study, reverse phase high pressure chromatography (RP-HPLC) method was used to detect proteolysis by native enzymes in high temperature heated milk. The aim of this research was to assess susceptibility of milk to proteolysis by native enzymes, after being subjected to various temperature- time processing conditions. Samples of raw and heated milk were clarified prior to analysis. Clarification was carried out to obtain pH 4.6 and 6% TCA soluble extracts, which were injected into RP- HPLC after filtration. This method confirmed that raw milk and milk processed at 85°C /15 s were the most proteolysed, indicating that the high temperatures employed during this study (110, 120, 130 and 142°C for 2s) inactivated the native enzymes. The RP-HPLC method is a useful method for the detection of proteolysis in milk.Item Detection of proteolysis in milk by four selected methods(The University of Reading, 2009) Chove, Lucy MlipanoSensitive methods that are currently used to monitor proteolysis are limited due to their high cost and lack of standardisation for quality assurance in the various dairy laboratories. In this study, four methods, trinitrobenzene sulphonic acid (TNBS), reverse phase high pressure liquid chromatography (RP-HPLC), gel electrophoresis and fluorescamine, were selected to determine their suitability for the detection of proteolysis in milk by added trypsin, plasmin, Pseudomonas fluorescens NCIMB 701274 (414) and Pseudomonas fluorescens NCIMB 702085 (416) and Bacillus licheniformis enzymes. Raw, pasteurised and UHT milk used to study proteolysis were analysed by the four methods. Pseudomonas fluorescens enzyme was extracted in this study since commercial enzymes are not available. All four methods confirmed that Pseudomonas fluorescens 416 was more proteolytic than Pseudomonas fluorescens 414. Dialysis was effective in the purification of Pseudomonas fluorescens (Ps. fl.) enzymes increasing the detection limit for the fluorescamine method, which had a low upper detection limit. Prominent peaks by RP-HPLC were shown to occur between 20-30 min for Pseudomonas fluorescens but 20-25 min for Bacillus licheniformis. RP-HPLC confirmed a peptide peak at 35 min in pH 4.6 soluble extract, which was absent in 6% TCA soluble extract, was from plasmin. Casein breakdown profiles by gel electrophoresis confirmed preference for 0-casein degradation over a and K-caseins by both Ps. fl. and B. licheniformis. Comparison of raw and pasteurised milk (72, 85 and 90°C for 15 s) revealed that pasteurisation was insufficient to inactivate plasmin inhibitors. The pH 4.6 and 6% TCA soluble extracts of UHT skim milk with added trypsin or plasmin showed high correlations (R2 > 0.93) by the TNBS, fluorescamine and RP-HPLC methods, confirming increased proteolysis during storage. Gel electrophoresis showed that breakdown products from trypsin were similar to plasmin although the former caused more extensive proteolysis than the latter due to higher enzyme activity, y-caseins, formed as a result of P-casein degradation disappeared (1484 and 742 BAEE units of added trypsin on days 3 and 7) due to extensive proteolysis. This finding had not previously been reported. Milk processed at high temperatures (110, 120, 130 and 142°C for 2 s) had lower proteolytic activities than raw milk and milk heated at 85°C implying inactivation of plasmin at temperatures of 110°C and above. This was observed in all the methods assessed. The TNBS method was recommended on the basis of its accuracy, reliability, simplicity and cost.Item Detection of proteolysis in milk by pseudomonas fluorescens using urea PAGE method(Macrothink Institute, 2017-12-28) Chove, Lucy Mlipano; Alistair, Grandison; Michael, LewisProteolysis of milk during storage by two strains of Pseudomonas NCIMB 702085 (414) and NCIMB 701274 (416) was investigated using the Urea PAGE method. Pseudomonas fluorescens enzymes were also extracted and purified by dialysis before inoculation into UHT skim milk in an attempt to partially purify the enzyme. Results showed that dialysis removed some peptides and amino acids which would interfere with the assay procedure. The method also confirmed that Pseudomonas fluorescens NCIMB 701274 (416) was more proteolytic than Pseudomonas NCIMB 702085 (414). Thus, Urea PAGE is a useful method for monitoring proteolysis in milk by Pseudomonas fluorescens.Item Development and performance evaluation of solar greenhouse dryer with desiccant energy storage system for tomatoes(Sokoine University of Agriculture, 2021) Mbacho, Susan AndrewTomato is one of the most important horticultural crops widely grown in the tropical East Africa countries. It is mostly used as vegetable recipe for food preparation at most homes or consumed raw as a salad. However, during the rainy season, tomato farmers experience widespread post-harvest losses due to insect and molds infestation. Also, during harvesting seasons, most markets in East Africa are flooded with the produce leading to over- supply against low demand resulting to heavy postharvest losses. Therefore, it is necessary to use appropriate drying technologies especially solar drying technology to reduce these losses. The use of solar drying technology is a good alternative solution to the problem of crop drying and especially the perishable tomato crop. Literature review show that most solar crop drying technologies developed for the past 50 years have very small loading capacity and cannot operate during the night. Therefore, in this study, we developed an integrated greenhouse solar dryer with Clay- CaCl 2 solid desiccant energy storage system. Solar greenhouse drying systems have an advantage over other solar drying systems because its structural simplicity combined with high loading capacity. In addition, they have relatively good thermal crop drying performance compared to most solar dryers. The system was tested under no-load and load conditions. The experimental study with no-load condition exhibited the mean collector temperature of 41.9 °C giving an average temperature rise of 14.7 °C (35%) above the ambient (27.2 °C) with an average R.H. value of 32.6% at the flow rate of 0.28 m 3 /s on the test date. When the desiccant energy storage was used during night an average greenhouse temperature recorded within the drying chamber was 26.5 °C higher than the ambient temperature of 15.9 °C (40 % temperature rise). The results obtained under desiccant energy storage showed that at a 0.07 m 3 /s air flow rate with an average rise in temperature of about 13.6 (32.3%) against the average ambient temperature of 28.5°C. The average relative humidity within the system was found to be 36.5% lower than the ambient R.H. (84.1%). The collector efficiencies obtained from no load test was 46.2% and 40.8% for the dryer and desiccant chamber respectively. The performance of the dryer was evaluated with fresh tomato load during the month of September - December 2019 at Kenyatta University field site. The dryer demonstrated capacity to dry fresh tomatoes from 93.9% (wb) to 8.3% (wb) within 27 hours with solar greenhouse drying efficiency of 23% while at night the dryer demonstrated desiccant drying efficient of 19.9%. The drying rate for the two-day solar drying was 0.985 kg/h and 0.875 kg/h respectively and that in night drying using desiccants was 0.34 kg/h. The economic analysis of the drying system shows a payback period of less than a year (0.54 year) with benefit-cost ratio of 8.4 implying that the system is economically viable. On the basis of these results, it was concluded that prototype solar greenhouse dryer with Clay-CaCl 2 energy storage system has great potential for tomato drying and other high moisture agricultural products in East African countries.Item Development and sensory evaluation of yoghurt flavoured with solar dried fruits(Pearl Research Journals, 2017) Ndabikunze, B. K.; Mumba, F. G.; Ngowi, H.; Chove, L; Mongi, R; Abdulsud, I.A study of developing solar dried fruit (5%) flavoured yoghurts using three types of fruits was conducted to determine acceptability and shelf life of developed products. A total of six samples namely banana, mango, pineapple, banana/mango, banana/pineapple and mango/pineapple were used as flavours in yoghurts. They were added either as fruit pieces or as powders. Shelf life projection study suggested that developed yoghurt products could be stored for up to 21 days at 4 °C without undergoing spoilage. Plain yoghourt (control) was the most liked sample and scored highest mean values for all attributes, which was significantly different from all other samples (p<0.05). Among the fruit flavoured yoghourts, mango was the most preferred sample in terms of flavor, aroma and general acceptability whereas the pineapple was the least acceptable. Although yoghurts flavoured with fruits pieces scored higher mean values in all sensory attributes than yoghurts flavoured with powdered fruits, no significant differences (p>0.05) between the two forms of fruit flavours was found. This needs to be further investigated. Thus, although the control was the most liked sample, solar dried fruit can be successfully used as yoghurt flavour, which may improve the texture and nutritional quality of the formulated yoghurts, making them available throughout the year, hence increasing farmer’s income.Item Diversity Of Underutilised Vegetables In Africa And Their Potential In The Reduction Of Micronutrient Deficiency:A Review(Science publishing Group, 2023) Zacharia,Abdulsudi Issa; Majaliwa,Nuria Kudra; Nyamete,Frida Albinusi; Chove,Lucy MlipanoMicronutrient deficiency affects all groups worldwide and is a major public health issue. It has devastating effects on all ages, especially in sub-Saharan Africa. It causes anemia, night blindness, increased mortality in children and pregnant women, osteoporosis in adults and rickets in children, lower infectious disease resistance, weariness, and cognitive impairment. Recent attention has focused on micronutrient deficits. Fortunately, these micronutrients are abundant in vegetables. Many African vegetables are endemic due to various weather variations. Diverse geographical areas on the continent allow for exotic and indigenous vegetable kinds. In Africa, many African Indigenous Vegetables (AIVs) are grown and eaten. Exotic veggies are popular in cities, but rural Africans still prefer indigenous crops. Despite their availability, most of the indigenous vegetables are underutilised and have not been adequately explored due to the decreased attention to their production, consumption and utilization. Due to their diversity, they have a great potential to contribute to food security by providing nutrient rich healthy diets. They are rich in vitamins and minerals and hence make a potential source of micronutrients that can help reduce the reported deficiencies. This paper provides a literature review on the wide variety of underappreciated vegetables grown in Africa, their health benefits, and their potential to alleviate micronutrient shortages. It also investigates the barriers to increasing consumption and explores some of the strategies that have been employed to address these problems. Due to their significant role in ensuring food and nutrition security, along with their rich nutrient composition, there exists an urgent imperative to enhance public awareness regarding their consumption and the attainment of nutritional security.