2647 research outputs found
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Effect of clarification on physicochemical properties and nutrient retention of pressed and blended cashew apple juice
Get PDFThis research article was published by Wiley Online Library, 2023The cashew apple is a nutritious pseudofruit of the cashew tree, after the nut. It is highly perishable and has an astringent taste, which hinder its utilization in the food sector. This study was designed to optimize clarification of cashew apple juice (CAJ) using gelatine, and assess the effect of clarification on physicochemical properties (titratable acidity, total soluble solids, and pH), nutrient retention, and sensory quality of pressed and blended CAJ. CAJ was treated with gelatine concentrations (0, 0.025, 0.05, 0.1, 0.2, 0.3, and 0.4 g/L) at room temperature (24–26°C) for 1, 2, 4, 6, 8, 10, and 12 h. Both clarified and unclarified juice were analyzed for tannin, total phenol, β-carotene, vitamin C, sugar, minerals, antioxidant activity, and physicochemical and sensory qualities. The results showed that tannin in pressed CAJ was optimally reduced from 217.6 mg/100 ml TAE to 24.6 mg/100 ml TAE, and from 258.0 mg/100 ml TAE to 55.0 mg/100 ml TAE in blended CAJ, using 0.2 g of gelatine in a liter of juice, for 2 h at room temperature. Both CAJ with and without clarification showed no significant difference in pH, total soluble solids, and titratable acidity (p < .05). However, blended CAJ had higher contents of total phenol, tannin, β-carotene, vitamin C, sugar, minerals, and antioxidant activity (p < .05). The use of a low concentration (0.2 g/L) of gelatine in a liter of either blended or pressed CAJ yielded sweet and less astringent CAJ with high-intensity yellow color. The technologies performed well at room temperature and therefore provide the basis for potential business investment
Environmental risks of a commonly used pyrethroid: Insights from temporary pond species of the Lake Manyara Basin, Tanzania
Get PDFThis research article was published by Elsevier, 2023Environmental risks posed by widespread pesticide application have attracted global attention. Currently, chemical risk assessments in aquatic environments rely on extrapolation of toxicity data from classic model species. However, similar assessments based on local species could be complementary, particularly for unusual living environments such as temporary ponds. Here, we carried out an environmental risk assessment (ERA) of a pyrethroid model compound, cypermethrin, based on local temporary pond species. First, we measured cypermethrin residue concentrations in rivers, irrigation canals and temporary ponds in the Lake Manyara Basin (LMB). Then, we estimated the environmental risks of cypermethrin by combining these data with acute toxicity data of three resident species across three trophic levels: primary producers (Arthrospira platensis), invertebrate grazers (Streptocephalus lamellifer) and fish (Nothobranchius neumanni). Furthermore, we compared the derived ERA to that obtained using toxicity data from literature of classic model species. Cypermethrin residue concentrations in contaminated systems of the LMB ranged from 0.01 to 57.9 ng/L. For temporary pond species, S. lamellifer was the most sensitive one with a 96 h-LC50 of 0.14 ng/L. Regardless of the assumed exposure concentration (0.01 and 57.9 ng/L), the estimated risks were low for primary producers and high for invertebrate grazers, both for local species as well as for classic model species. The highest detected cypermethrin concentration resulted in a moderate risk estimation for local fish species, while the estimated risk was high when considering classic fish models. Our results confirm that, at least for pyrethroids, ERAs with classic model species are useful to estimate chemical risks in temporary pond ecosystems, and suggest that complementary ERAs based on local species could help to fine-tune environmental regulations to specific local conditions and conservation targets
Lablab purpureus: Analysis of landraces cultivation and distribution, farming systems, and some climatic trends in production areas in Tanzania
Get PDFThis research article was published by De Gruyter Open Access, 2023Lablab is a multifunctional crop that is underutilized in Africa. This study was performed to assess Lablab landraces cultivation and distribution, farming systems, and some climatic trends in Lablab production areas in Tanzania. A socio-economic survey was engaged to locate the main production areas using Global Positioning System, while participatory research tools were used to assess farming systems, practices, and challenges perceived in Lablab production. Some weather data were collected to establish climatic trends in Lablab production areas. The study revealed a wide cultivation and distribution of Lablab landraces in five agro-ecological zones with some variations. These variations were influenced by market demand for Lablab in Kenya and its role in subsistence farming. Lablab was mainly produced for conservation agriculture and enhanced soil fertility (27.9%), marketing (22.1%), livestock feeding (21.5%), food during drought conditions (15.4%), traditional purposes (7.4%), regular consumption (3.8%), and other minor uses (1.8%) varied significantly across the zones (χ 2 = 37.639, p = 0.038). The farming systems included intercropping (59.0%), mono-cropping (31.0%), home based gardening (5.0%), crop rotation (3.0%), and relaying cropping (2.0%) with no significant difference across the zones (χ 2 = 15.049, p = 0.314). A wide range of farmers’ practices were noted in Lablab production zone-wise. Unavailability of improved varieties and poor market channels were the farmers’ key challenges in Lablab production. It was further noticed that Lablab was mainly produced in areas with dry conditions. Finally, it was suggested that effort should be enhanced to improve genetic resource conservation, value addition, and market channels to other countries while developing improved varieties in terms of high yielding and drought tolerance
Pathways from research to sustainable development: Insights from ten research projects in sustainability and resilience
Get PDFThis research article was published by Springer nature linkDrawing on collective experience from ten
collaborative research projects focused on the Global
South, we identify three major challenges that impede the
translation of research on sustainability and resilience into
better-informed choices by individuals and policy-makers
that in turn can support transformation to a sustainable
future. The three challenges comprise: (i) converting
knowledge produced during research projects into
successful knowledge application; (ii) scaling up
knowledge in time when research projects are short-term
and potential impacts are long-term; and (iii) scaling up
knowledge across space, from local research sites to larger-
scale or even global impact. Some potential pathways for
funding agencies to overcome these challenges include
providing targeted prolonged funding for dissemination
and outreach, and facilitating collaboration and
coordination across different sites, research teams, and
partner organizations. By systematically documenting
these challenges, we hope to pave the way for further
innovations in the research cycl
Valorization of palm oil wastes into oyster mushrooms (Pleurotus HK-37) and biogas production
Get PDFThis research article was published in the Qeios in 2023Continued growth of oil palm cultivation for palm oil production has led to higher post-processing wastes that pose
environmental management challenges. The goal of this study was to investigate the co-production of oyster
mushroom Pleurotus HK-37 and biogas as a means to add value to palm oil waste fractions and thus reduce their
impact on the environment. A total of 9 blends of solid, semi-solid and liquid palm oil waste fractions were subjected to
mushroom production and the resulting spent mushroom substrate (SMS) was used for biogas production. There was a
significant difference in mushroom yield (t-test, p = 0.00013237) and biological efficiency (t-test, p = 0.00044955), with
the highest values obtained from substrate formulation no. 3 (1:1 PMF and EFB (each 49% total weight) supplemented
with POME and SD at 1%). Biogas production was also significantly different among both fresh and pretreated (SMS)
waste fractions. The highest biogas volume, methane content and methane yield were observed from SMS waste
fractions no. 4 (1:1 PMF and EFB (each 44% total weight) supplemented with PPC and PKS at 5% and POME and SD
at 1%). Overall, pretreatment of palm oil processing waste with oyster mushrooms increased biogas production and
methane yield per kg volatile solids by 102.78% compared to untreated waste. This study has demonstrated that
mushroom and biogas production are viable options for the management of palm oil processing waste fractions and
thus promoting a circular economy. Further studies should optimize their production and conduct techno-economi
Preliminary symbiotic performance of indigenous soybean (Glycine max)-nodulating rhizobia from agricultural soils of Tanzania
Get PDFThis research article was published in the Frontiers in Sustainable Food Systems, Volume 6, 2023Globally, the increase in human population continues to threaten the sustainability of
agricultural systems. Despite the fast-growing population in Sub-Saharan Africa (SSA)
and the efforts in improving the productivity of crops, the increase in the yield of crops
per unit area is still not promising. The productivity of crops is primarily constrained by
inadequate levels of soil nutrients to support optimum crop growth and development.
However, smallholder farmers occasionally use fertilizers, and the amount applied is
usually small and does not meet plant requirements. This is due to the unaffordability
of the cost of fertilizers, which is enough to suffice the crop requirement. Therefore,
there is a need for alternative affordable and effective fertilization methods for
sustainable intensification and improvement of the smallholder farming system’s
productivity. This study was designed to evaluate the symbiotic performance of
indigenous soybean nodulating rhizobia in selected agricultural soils of Tanzania.
In total, 217 rhizobia isolates were obtained from three agroecological zones, i.e.,
eastern, northern, and southern highlands. The isolates collected were screened for
N2 fixing abilities under in vitro (nitrogen-free medium) and screen house conditions.
The results showed varying capabilities of isolates in nitrogen-fixing both under in
vitro and screen house conditions. Under in vitro experiment, 22% of soybean rhizobia
isolates were identified to have a nitrogen-fixing capability on an N-free medium, with
the highest N2-fixing diameter of 1.87 cm. In the screen house pot experiment, results
showed that soybean rhizobia isolate significantly (P < 0.001) influenced different
plant growth and yield components, where the average shoot dry weight ranged from
2.49 to 10.98 g, shoot length from 41 to 125.27 cm whilst the number of leaves per
plant ranged from 20 to 66. Furthermore, rhizobia isolates significantly (P = 0.038)
increased root dry weight from 0.574 to 2.17 g. In the case of symbiotic parameters
per plant, the number of nodules was in the range of 0.33–22, nodules dry weight
(0.001–0.137 g), shoot nitrogen (2.37–4.97%), total nitrogen (53.59–6.72 g), and fixed
nitrogen (46.878–0.15 g) per plant. In addition, the results indicated that 51.39% of
the tested bacterial isolates in this study were ranked as highly effective in symbiosis,
suggesting that they are promising as potential alternative biofertilizers for soybean
production in agricultural soils of Tanzania to increase productivity per unit area while
reducing production cost.biological nitrogen fixation, rhizobial isolates, soybean, soybean-nodulating rhizobia,
symbiotic performanc
Review on the secondary metabolites, biological properties, and ethnomedicinal uses of the component species of the buheri wa afya formula used to treat COVID-19 in Tanzania
Get PDFThis research article was published in the Phytomedicine Plus, Volume 4, Issue 1, 2023Background: It has proven difficult to treat viral infections like SARS-CoV, MERS-CoV, and SARS-CoV-2 that cause
severe respiratory disorders with the currently available medications. Alternative strategies for combating viral
infections are required to adequately treat infectious diseases like COVID-19. The most potent of them all may be
plant-based products or herbal remedies. Following the advent of the COVID-19 epidemic, a number of alter-
native medicine practitioners in Tanzania developed herbal medicine formulations, claiming that they were
effective in treating COVID-19 patients. One among the formulations is Buheri wa Afya, meaning "good health".
The rationale for choosing Buheri wa Afya over the other formulations was justified by its efficacy in treating
COVID-19 patients at different stages of the illness.
Purpose: This review aimed to collect information on the chemical composition, biological properties, and eth-
nomedicinal uses of the constituents of Buheri wa Afya formula, a plant-fungi complex formula made of
Adansonia digitata L., Ficus sur Forssk, Securidaca longipedunculata Fresen, Syzygium cumini (L.) Skeels, and Zan-
thoxylum chalybeum Engl., and a fungus, Ganoderma tsugae Murrill, that was and is still used for the treatment of
COVID-19 in Tanzania.
Methods: All information regarding ethnomedical applications, chemical compositions, and biological properties
related to the constituents of the herbal formula was collected from PubMed, Research4Life, Google Scholar,
Science Direct, Web of Science, Wiley Online Library, Springer, Research Gate link, and published books.
Results: The search, which mostly focused on COVID-19 and other viral infectious diseases produced a total of
183 publications, with publication dates ranging from 1984 to 2023. Most of the articles originated from African
and Asian (specifically China and India) countries. A total of 16 articles spanning between 1984 through 1999
reporting on a variety of topics, such as isolation of compounds and biological testing were collected. During that
time, Ganoderma species had the highest number of reported occurrences. In contrast to the 25 papers collected
between 2000 and 2009, 78 articles covering the years 2010 through 2019 were collected. These 103 articles
reported studies on ethnomedicinal uses, pharmacological properties, and chemical compositions of the plants
and mushrooms under review. During the 2020–2023 period, a total 67 different articles were gathered, the
major focus being the fight against COVID-19 and other viral infectious diseases. Twelve of them reported the
ethnomedical applications of the investigated plant and mushroom species in the Buheri wa Afya formula in the
management and treatment of COVID-19 and associated symptoms. The majority of articles reported the pres-
ence of a variety of biologically active compounds, including vitamins, flavonoids, phenols, coumarins, alkaloids,
terpenoids, macronutrients, and micronutrients. According to the studies, the compounds have been reported to
exhibit anti-inflammatory, immunomodulatory, antiviral, antioxidant, antimalarial and many other biological
properties. The combination of the observed biological properties of the plant and mushroom species in the
Buheri wa Afya formula may be responsible for its effectiveness in the treatment of COVID-19 in Tanzani
Design of a Cooling System Integrated with Ultraviolet Light for Preservation of Fruits and Vegetables at Variable Tropical Weather Conditions: A Case Study of Arusha, Tanzania
Get PDFThis research article was published by / Tanzania Journal of Science / Vol. 49 , 2023Post-harvest losses of fruits and vegetables pose significant challenges, especially in tropical climates. This study introduces the development and performance evaluation of a solar-powered evaporative cooling storage system integrated with ultraviolet light (UV) designed for preservation of perishable fruits and vegetables. The cooling chamber supplied with ultraviolet lamp was developed using locally available materials such as sisal, sponge, and bricks. The performance of the system was evaluated in terms of air temperature decrease, relative humidity increase, and evaporative cooling power capacity both for sunny and cloudy tropical weather conditions. The study reveals that activating the UV light considerably extends the shelf life of fruits and vegetables. The system was able to extend the shelf life of perishable products by up to 21 days when exposed to ultraviolet light and by 9 days when not exposed to ultraviolet light. On sunny days, active system operation leads to an average temperature reduction of 5.0 °C, along with a relative humidity increase of 23%. On the contrary, on cloudy days, the cooling impact diminishes slightly, resulting in temperature decrease of approximately 3.5 °C and relative humidity increase of 18%. These findings emphasize the potential of the solar-powered evaporative cooling system, combined with UV light treatment, as a viable approach to combat post-harvest losses in tropical environments
Assessing the Impacts of Land Use and Climate Changes on River Discharge towards Lake Victoria
Get PDFThis research article was published by MDPI in 2023The Lake Victoria basin’s expanding population is heavily reliant on rainfall and river flow
to meet their water needs, making them extremely vulnerable to changes in climate and land use. To
develop adaptation and mitigation strategies to climate changes it is urgently necessary to evaluate the
impacts of climate change on the quantity of water in the rivers that drain into Lake Victoria. In this
study, the semi-distributed hydrological SWAT model was used to evaluate the impact of current land
use and climate changes for the period of 1990–2019 and assess the probable future impacts of climate
changes in the near future (2030–2060) on the Simiyu river discharge draining into Lake Victoria,
Northern Tanzania. The General Circulation Model under RCPs 4.5, 6.0 and 8.5 predicted an increase
in the annual average temperature of 1.4 ◦C in 2030 to 2 ◦C in 2060 and an average of 7.8% reduction
in rainfall in the catchment. The simulated river discharge from the hydrological model under RCPs
4.5, 6.0 and 8.5 revealed a decreasing trend in annual average discharge by 1.6 m3/s from 5.66 m3/s
in 2019 to 4.0 m3/s in 2060. The increase in evapotranspiration caused by the temperature increase
is primarily responsible for the decrease in river discharge. The model also forecasts an increase in
extreme discharge events, from a range between 32.1 and 232.8 m3/s in 1990–2019 to a range between
10.9 and 451.3 m3/s in the 2030–2060 period. The present combined impacts of climate and land
use changes showed higher effects on peak discharge at different return periods (Q5 to Q100) with
values of 213.7 m3/s (Q5), 310.2 m3/s (Q25) and 400.4 m3/s (Q100) compared to the contributions
of climate-change-only scenario with peak discharges of 212.1 m3/s (Q5), 300.2 m3/s (Q25) and
390.2 m3/s (Q100), and land use change only with peak discharges of 295.5 m3/s (Q5), 207.1 m3/s
Q25) and 367.3 m3/s (Q100). However, the contribution ratio of climate change was larger than
for land use change. The SWAT model proved to be a useful tool for forecasting river discharge in
complex semi-arid catchments draining towards Lake Victoria. These findings highlight the need for
catchment-wide water management plans in the Lake Victoria Basin
Fuzzy modelling on the depletion of forest biomass and forest-dependent wildlife population
Get PDFA project report submitted in Franklin Open Volume 4, September 2023,This paper presents a system of non-linear differential equations describing the depletion of forest biomass and forest-dependent wildlife population caused by human population and its associated activities. The model incorporates the imprecise nature of the parameters, which are treated as triangular fuzzy numbers to reflect the inherent uncertainty. We utilised cut to transform these imprecise parameters into intervals. Subsequently, employing the principles of interval mathematics, we effectively converted the related differential equation into a pair of distinct differential equations. By leveraging the signed distance of the fuzzy numbers, we further simplified the equations, resulting in a single differential equation, which led to the formulation of a defuzzified model. The existence of equilibrium points with their stability behaviour is presented. Furthermore, the existence of trans-critical bifurcation is analysed. Through numerical simulations, we observe significant differences between the solutions of system in crisp and fuzzy environments. These findings highlight the importance of using fuzzy models to accurately represent the dynamics of complex natural systems. Consequently, we conclude that fuzzy models provide a trustworthy representation of the dynamics of complex natural systems