Bagasse, a by‐product from raw sugar factories, is conventionally burned for energy production. In this study, bagasse extracts from hydrothermal liquefaction (HTL) treatment (160 °C, 1 MPa and 30 min) with a carbohydrate content of 510.3 mg g⁻¹ and 0.5 mg g⁻¹ of total phenols were applied as emulsifiers in oil‐in‐water (O/W) emulsions. Bagasse extracts from HTL (0.5–4 wt%) lowered the interfacial tension between oil–water interphase from 19.8 to 14.0 mN m⁻¹, owing possibly to the surface‐active hydrophilic carbohydrate‐hydrophobic lignin complexes in the extracts (lignin content: 7.1% w/w). Emulsions stabilised by bagasse extracts from HTL with average droplet size, dₐᵥ of 0.79 μm were comparable with gum arabic (GA), dₐᵥ of 2.24 μm after 11 days at 25 °C. Bagasse extracts containing biopolymers have the potential for industrial applications involving emulsion systems; therefore, HTL treatment of bagasse without any solvents can be regarded as an effective tool for producing natural emulsifiers.

Potential of bagasse obtained using hydrothermal liquefaction pre-treatment as a natural emulsifier

Climate change is predicted to impact species' genetic diversity and distribution. We used Senegalia senegal (L.) Britton, an economically important species distributed in the Sudano-Sahelian savannah belt of West Africa, to investigate the impact of climate change on intraspecific genetic diversity and distribution. We used ten nuclear and two plastid microsatellite markers to assess genetic variation, population structure and differentiation across thirteen sites in West Africa. We projected suitable range, and potential impact of climate change on genetic diversity using a maximum entropy approach, under four different climate change scenarios. We found higher genetic and haplotype diversity at both nuclear and plastid markers than previously reported. Genetic differentiation was strong for chloroplast and moderate for the nuclear genome. Both genomes indicated three spatially structured genetic groups. The distribution of Senegalia senegal is strongly correlated with extractable nitrogen, coarse fragments, soil organic carbon stock, precipitation of warmest and coldest quarter and mean temperature of driest quarter. We predicted 40.96 to 6.34 per cent of the current distribution to favourably support the species' ecological requirements under future climate scenarios. Our results suggest that climate change is going to affect the population genetic structure of Senegalia senegal, and that patterns of genetic diversity are going to influence the species' adaptive response to climate change. Our study contributes to the growing evidence predicting the loss of economically relevant plants in West Africa in the next decades due to climate change.

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Genetic diversity and distribution of Senegalia senegal (L.) Britton under climate change scenarios in West Africa

The contribution of frankincense to the agro-pastoral household economy and its potential for commercialization - A case from Borana, southern Ethiopia

Tree planted fallow is an agroforestry system that may restore degraded soils and protect them from erosion. In this study, sandy soils properties of Acacia senegal planted fallows (AF) were assessed and compared to those from the continuous cropped system (CC) in 3 sites from Northern Cameroon in order to determine its suitability to restore soil fertility and sustain crop productivity. Soil samples were collected from the topsoil (0 to 20 cm) and the subsoil (20 to 40 cm) and subjected to physicochemical analyses. The trials were established for 2 consecutive years, respectively with sorghum (Sorghum bicolor) and cowpea (Vigna unguiculata). Results confirmed the sandy (more than 80% of sand) and acidic (4.42 ≤ pH ≤ 6.59) soil characters. In every site, topsoil from AF was relatively more fertile than from CC. Globally, nutrients content were influenced by tree density and fallow duration. The more improved elements were organic matter, nitrogen and pH. Sorghum and cowpea yields were quite variable depending on fallow duration, tree density and conversion form. The highest crop yields (3.4 tha-1 for sorghum and 2.4 tha-1 for cowpea) were obtained in 19 years old AF converted by partial clear-felling. The intercropping process by partial clear-felling of trees was the best conversion form. Overall findings indicated that fallowing with A. senegal can reduce soil acidity, restore nutrients and therefore it constitutes a suitable agroforestry system that may sustain annual crops productivity. However, researches have to determine the best tree density for intercropping and the tools for their sustainable management.  

	Key words: Acacia senegal fallow, agroforestry, sandy soils, continuous cropping, North Cameroon.

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Sandy soil fertility restoration and crops yields after conversion of long term Acacia senegal planted fallows in North Cameroon.

Avant-dernier pays au monde pour son indicateur de developpement humain selon la classification du Pnud, en 2002, le Niger semble cumuler les handicaps. Malgre des conditions naturelles tres difficiles et une conjoncture economique plutot defavorable, certains operateurs prives, tels que les dirigeants du groupe franco-nigerien Asi, ont pris le risque d'investir dans le pays et de tirer parti de ses maigres atouts. La principale action menee par ces entrepreneurs a consiste a redynamiser la filiere nigerienne de la gomme arabique. Grâce a ses diverses particularites et aux strategies de ses dirigeants, le groupe s'est progressivement impose sur le plan international en parvenant a reorganiser la filiere et a donner une nouvelle image de la gomme nigerienne.

La redynamisation de la filière gomme arabique au Niger : un exemple d'initiative privée : Gommiers sahéliens

As gum arabic is widely used in food and non-food industries, demand is high all over the world. Still, smaller production countries in West Africa such as Cameroon, Niger and Senegal seem to have so many difficulties producing and commercializing gum arabic that their market shares have declined significantly over the years despite their production potential. This paper reviews the development of the gum arabic market chains in Cameroon, Niger and Senegal, in order to evaluate the limiting factors and identify appropriate strategies to the sector progress. The main challenges in production and commercialization are limited knowledge and management of resources, pricing and quality. Some of the general strategies that could improve performance are the professionalization of the sector, the integration of Acacia senegal development into rural economic activities, capacity building for producers and other actors, and the organization of the marketing system.

https://bioone.org/journals/international-forestry-review/volume-15/issue-2/146554813806948477/Common-Challenges-in-Gum-Arabic-Production-and-Commercialization-in-West/10.1505/146554813806948477.pdf

AM Zoubeirou

Papers

Common challenges in gum arabic production and commercialization in West Africa: a comparative study of Cameroon, Niger and Senegal