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Oluwatoyin Ayetigbo, Sajid Latif, Adebayo Abass, Joachim Müller. 2019. Preparation, optimization and characterization of foam from white-flesh and yellow-flesh cassava (Manihot esculenta) for powder production. Food Hydrocolloids (97)

Cassava foam, another form in which cassava may potentially be used as food, was produced from the pulp of
yellow-flesh and white-flesh cassava varieties by whipping with foaming agent (20 %w/w glycerol monostearate
colloid, GMS) and stabilizer (sodium carboxymethyl cellulose, NaCMC). Cassava foaming was optimized for
concentration of foaming agent, stabilizer and whipping time. Using Box-Behnken experimental design, two
responses were measured: foam expansion (FE, %) and foam density (FD, g/mL). White-flesh cassava pulp required
14.97% GMS, 0.51% NaCMC and 2.07 min to give a foam of 52.63% expansion and density of 0.75 g/mL.
Yellow-flesh cassava pulp required 14.29% GMS, 0.6% NaCMC and 2 min to yield a foam of 48.25% expansion
and density of 0.76 g/mL. Predicted optimal FE and FD were 54.9% and 0.73 g/mL for white-flesh cassava foam,
and 49.86% and 0.73 g/mL for yellow-flesh cassava foam, respectively, and are close to validated values. The
optimal foams were quite stable after 4 h at 25 ± 2 °C, with low volume collapse of 1.79% and 1.26% for white
and yellow cassava foams, respectively. The optimal cassava foams were dried into foam powder. There was
significant difference in color values (L*, a*, b*, C*, E*, H*, % W, Eyellow white) and total carotenoids content of
pulp, optimal foam, and powder of both varieties. Microstructure analysis of the optimal foams revealed round
air bubbles and positive skewed distribution of bubble sizes. Foaming and drying significantly reduced total
cyanogenic potential in cassava, and may be considered as processing operations capable of reducing cyanogenic
potential in cassava considerably.

Show details Posted by : MSc. Ayetigbo Oluwatoyin Elijah

Oluwatoyin Ayetigbo, Sajid Latif, Adebayo Abass, Joachim Müller. 2019. Osmotic dehydration kinetics of biofortified yellow-flesh cassava in contrast to white-flesh cassava (Manihot esculenta). Journal of Food Science and Technology

In recent times, the cultivation, processing and
consumption of biofortified yellow-flesh cassava is of
significant interest to breeders and food processors due to
its relatively high pro-vitamin-A content, compared to the
conventional white-flesh cassava. In light of this, osmotic
dehydration (OD) kinetics of a recently released biofortified
yellow-flesh cassava was compared to that of a whiteflesh
cassava, using salt, sugar, and salt–sugar solutions at
different temperatures (30, 45, 60 C) and fixed cube/solution-
ratio. Water loss (WL) and solids gain (SG) data
were fitted by non-linear regression using four models
(Page, Weibull, Azuara, and Peleg). Azuara model was
most appropriate in describing OD kinetics for both cultivars.
Azuara estimates for equilibrium WL and equilibrium
SG, respectively, ranged between 0.101–0.120 and
0.049–0.094 g/g for salt solution, 0.158–0.212 g/g and
0.107–0.268 g/g for sugar solution and 0.234–0.306 g/g
and 0.189–0.276 g/g for salt–sugar solution. The best
conditions for OD of both cultivars by salt solution and
sugar solution was at 60 C and 45 C, respectively, while
that for salt–sugar solution varied with cultivar. Increasing
temperature increased water loss and solids gain. Salt-OD
conformed to Arrhenius temperature dependence of diffusivity,
but sugar-OD and salt–sugar-OD did not. Micrographs
reveal biofortified yellow-flesh cassava was more susceptible to cell wall collapse than white-flesh cassava.
Extent of dehydration by OD agents ranked: salt–sugar[
sugar[salt. Osmotic dehydration may be useful as a
means of dehydration for cassava prior to drying, and is
especially relevant for the carotenoids-rich biofortified
yellow cassava.

Show details Posted by : MSc. Ayetigbo Oluwatoyin Elijah

Srivastava Amit Kumar, Mboh Cho Miltin, Gaiser Thomas, Ewert Frank. 2016. Impact of climatic variables on the spatial and temporal variability ofcrop yield and biomass gap in Sub-Saharan Africa- a case study inCentral Ghana. Elsevier

We investigated the impact of climate variables on yield and biomass gap variability in two humid topi-cal regions, Brong-Ahafo and Ashanti region, of central Ghana using the crop model LINTUL5 embedded into a general modeling framework, SIMPLACE (Scientific Impact Assessment and Modelling Platform for Advanced Crop and Ecosystem Management). The simulations were run using a late maturity maize variety (Obatanpa) and historical weather data (1992–2007) across the 18 districts of the regions studied. The simulated maize yield and biomass production under water-limited conditions varied spatially which was significantly correlated with the solar radiation and precipitation in the crop growing period , whereas, associated temporal variability in the simulated maize yield was significantly correlated with the radiation in the crop growing period.

Show details Posted by : Arthur

Legese Getachew, van Assche Kristof, Stellmacher Till, Tekleworld Hailemariam, Kelboro Girma. 2018. Land for food or power? Risk governance of dams and family farms in Southwest Ethiopia. Elsevier

We use the concepts of riskscapes and risk governance to analyze the tensions between land use for food (farms) and energy (dams) in Southwest Ethiopia. We analyze the linkages between risk perception, risk assessment and risk management for local and non-local actors. We distinguish, after empirical analysis, as main riskscapes the riskscapes of landlessness, food and energy insecurity and siltation. For the Ethiopian case, and more generally, we reflect on the potential of spatial planning as a site of risk governance, where risk perception, assessment and management can be discussed in their linkages, where different actor-related and topical riskscapes can encounter, can be deliberated and result in policy integration. We finally reflect on the ethical implications of our perspective and reconsider the idea of social cost.

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Latif Sajid, Müller Joachim. 2015. Potential of cassava leaves in human nutrition: A riveiw. Trends in Food Science & Technology

Cassava is mainly grown for its root tubers whereas its leaves are mainly considered as a byproduct. However, cassava leaves are a rich source of roughage, protein, minerals, and vitamins. But, the presence of anti nutrients and cyanogenic glucosides are the major drawbacks in cassava leaves which limit its human consumption. These anti-nutrients and toxic compounds of cassava leaves cause various diseases depending on the consumption level. Hence these anti-nutrients and toxic potential of cassava leaves should be addressed during cassava leaf processing (CLP) before human consumption. Several CLP methods have been developed but every method has its own limitations. Some CLP methods successfully detoxify cassava leaves but simultaneously destroy the nutrients. Efforts have also been made for cassava leaf protein extraction in the form of cassava leaf protein concentrate (CLPC) but protein recovery was very low. This review summarizes the nutrient, anti-nutrient and toxic composition of cassava leaves, CLPC, different CLP methods, human consumption and diseases caused by cassava leaves. Furthermore, recommendations have been made in order to encourage cassava leaves consumption as an important source of protein and micro-nutrients.

Show details Posted by : Arthur

Frank Susanne, Fürst Christine, Pietzsch Frank. 2015. Cross-Sectoral Resource Management: How Forest Management Alternatives Affect the Provision of Biomass and Other Ecosystem Services. Forests

Integrated forest management is faced with the challenge that the contribution of forests to economic and ecological planning targets must be assessed in a socio-ecological system context. This paper introduces a way to model spatio-temporal dynamics of biomass production at a regional scale in order to derive land use strategies that enhance biomass provision and avoid trade-offs for other ecosystem services. The software platform GISCAME was employed to bridge the gap between local land management decisions and regional planning by linking growth and yield models with an integrative mesoscale modeling and assessment approach. The model region is located in Saxony, Germany. Five scenarios were simulated, which aimed at testing different alternatives for adapted land use in the context of climate change and increasing biomass demand. The results showed, for example, that forest conversion towards climate-change-adapted forest types had positive effects on ecological integrity and landscape aesthetics. In contrast, negative impacts on landscape aesthetics must be expected if agricultural sites were converted into short rotation coppices. Uncertainties with stem from assumptions regarding growth and yield models were discussed. Future developmental steps which consider, for example, accessibility of the resources were identified.

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Callo-Concha D, Denich M, Ul Hassan M M, Place F, Wardell D A. 2017. Lessons for research, capacity development and policy in agroforestry for development. Agroforestry Systems

Since its foundation in the 1970’s, agroforestry science has evolved from setting its concepts,
research approaches and flagship technologies towards its increasing contribution to ecologically sound land use, food security and income generation in the global North and South. The Third World Congress on Agroforestry held in Delhi in April 2014 continued contributed to this evolution by focusing, beyond the scientific realm, on the implementation of findings by convening ad-hoc stakeholders and subjects. Accordingly, some of the congress sessions dealt with key aspects of how agroforestry can foster and contribute to development. The special
issue ‘‘Lessons for research, capacity development and policy in agroforestry for development’’ compiles approaches, experiences and overall lessons from (i) research, (ii) capacity development, and (iii) policy-making, capable to promote and generate developmental change through agroforestry. This introductory paper outlines the rationale for the three areas and the contributing articles.

Show details Posted by : Arthur

Callo-Concha D, Denich M, Lamers J P A, Schwachula A, Hornidge A K, Khamzina A, Borgemeister C. 2016. Bridging science and development: lessons learnt from two decades of development research. Agroforestry Systems

This paper presents the theoretical, operational and implementation premises that guide the
development research agenda of the Center of Development Research (ZEF), exemplified by three agroforestry-related case studies. First, the importance, assumptions, conditions and priorities for development research in the context of developing countries are reviewed. Second, the three core premises of ZEF’s research approach, (1) transdisciplinary to carry out research on real-life problems, (2) symmetrical partnerships with local stakeholders to sustain ground
activities and ensure implementation, and (3) capacity development to warrant future competences, are exposed. Third, these premises are exemplified and mirrored in three agroforestry-related case-studies: (1) slash-and-burn agriculture in the Brazilian Amazon,
(2) socio-ecological management of coffee-agroforests in Ethiopia, and (3) afforestation with multipurpose tree species in Uzbekistan. The paper concludes by streamlining the theoretical and practical premises exposed with the presented case-studies, and confirming how these have guided ZEF in the planning, implementation and continuation of development research programs. Although ZEF’s approach to development research is dynamic and continuously subject to assessment, its core remains guiding even after two decades of implementation, appearing to be a suitable pathway for reaching development objectives.

Show details Posted by : Arthur