Diagnostic des systèmes techniques de transformation de l'igname en cossettes séchées au Bénin

Les pertes après-récolte des tubercules d'igname enregistrées dans les pays producteurs de l'Afrique de l'Ouest sont très importantes (40-50 % après 6 mois de stockage). Ces pertes sont dues à l'absence de moyens et méthodes de conservation appropriés. La transformation des tubercules en produits stables (cossettes, farine) est une solution à la conservation de l'igname frais. Cette technique permet, en outre, de réduire de plus de la moitié le poids de la matière à transporter. La méthode de fabrication des cossettes d'igname, connue depuis longtemps au Bénin et dans les pays voisins (Nigeria, Togo), permet de conserver le surplus des tubercules pour les utiliser pendant les périodes de soudure. Depuis plus d'une décennie, la farine de cossettes d'igname (Elubo) est passée dans les habitudes alimentaires des populations urbaines. L'importance de la demande actuelle nécessite que cette technique soit évaluée, améliorée et valorisée

Biodiversité des emballages-feuilles végétales utilisées dans l’artisanat agroalimentaire au Sud du Bénin

Objectif : Le présent travail vise spécifiquement à identifier les espèces de feuilles végétales utilisées traditionnellement comme emballages dans l’artisanat agroalimentaire au sud du Bénin et à décrire les traitements mis en jeu à cet effet.Méthodologie et résultats : Une enquête sur les emballages-feuilles végétales a été réalisée par ratissage systématique de 150 productrices-vendeuses de denrées alimentaires au sud-Bénin. Les espèces de feuilles végétales ont été identifiées par référence à la base des données disponibles à l’herbier national. Thalia geniculata, (Thalia) Tectona grandis, (Teck) Manihot esculenta (Manioc, manioc doux, cassave), Musa chinensis, (Bananier) Lasimorpha senegalensis (Grand arum du Sénégal, maïs de marécage, oreille d'éléphant) Icacina trichantha (Icacina), Elaeis guineensis (palmier à huile) et Sterculia tragacantha, (Sobou Tagacanthe africain) étaient les principales espèces végétales identifiées et utilisées par environ 98% des productrices enquêtées. Le rapport pondéral moyen des emballages-feuilles aux denrées alimentaires variait entre 0,05 et 0,53 (p/p) et pourrait être un indicateur associé à la durée de conservation des aliments.Conclusion et application : Du fait de leur caractère biodégradable, de leur diversité et d’un éventail de propriétés et caractéristiques intrinsèques, les feuilles végétales utilisées comme emballages jouent un rôle clé dans l’artisanat agroalimentaire au Sud-Bénin. Outre la fonction de protection qu’elles assurent, certaines espèces de feuilles telles que Sterculia tragacantha (Tragacanthe africain), Manihot glaziovii (Manioc caouchouc), Manihot esculenta (Manioc), Thalia geniculata (Thalia) et Tectona grandis  (Teck) sont également consommées comme légumes feuilles ou utilisées pour leurs propriétés médicinales pendant que d’autres (Daniellia oliveri (Copalier africain de balsam, santan), Sterculia tragacantha (Sobou, Tragacanthe africain) Canna indica (Canna, Basilier, Grain de plomb de l’Inde), Tectona grandis) transfèreraient leur arome ou couleur aux aliments emballés. Les effets bénéfiques (protecteur, conservateur, nutritionnel, aromatique ou thérapeutique) ou néfastes (toxicité, facteurs antinutritionnels) sur les denrées alimentaires emballées doivent être mis  en évidence et documentés pour la promotion d’emballages végétaux compatibles avec les normes des emballages modernes et respectueux de l’environnement.Mots clés Emballages biodégradables, Emballages multi produits, Emballage multi-local ; Biodiversité ; Béni

Softening effect of Ikpiru and Yanyanku, two traditional additives used for the fermentation of African Locust Bean (Parkia biglobosa) seeds in Benin

Ikpiru and Yanyanku are two additives used for the traditional alkaline fermentation of African locust bean (Parkia biglobosa. Benth) to produce food condiments in Benin. In this study, African locust beans (Parkia biglobosa. Benth) were fermented with or without Ikpiru and Yanyanku to assess the factors explaining the softening role of these additives during the fermentation process. Changes in microbial population, chemical components and texture parameters of the fermented cotyledons were determined during the fermentation process. Bacillus spp. predominated during the fermentation, with an upward trend. The use of Yanyanku or Ikpiru seems to increase Bacillus count during the earlier stage (between 0 and 18 hours) of fermentation, since the variations were 35% and 43% (growth rate of 0.13 and 0.16 Log10 h-1) for trial with Yanyanku and Ikpiru respectively, versus 6% (0.02 Log10 h-1) for the control. Despite this initial gap, the final count (after 48 h) did not show any significant difference between the control and samples with additives. Compressing forces were significantly lower between 12 to 24 h for cotyledons fermented with additives than for the control, suggesting a rapid disintegration, i.e., the softening effect of Yanyanku and Ikpiru during the fermentation of African locust bean seeds. No significant difference (p > 0.05) was observed between proximate composition of the samples fermented without additives and those fermented with additives.Keywords: Fermentation, Bacillus, softening effect, softenin

Effect of variety and processing method on functional properties of traditional sweet potato flour (“elubo”) and sensory acceptability of cooked paste (“amala”)

“Amala” is a generic term in Nigeria, used to describe a thick paste prepared by stirring flour (“elubo”) from yam, cassava or unripe plantain, in hot water, to form a smooth consistency. In order to overcome its high perishability and increase the utilization of sweet potato roots, three varieties of sweet potato roots were processed into flour using two methods. The interactive effect of variety and the processing method had a significant effect (P < 0.05) on all the functional properties of the flour except yellowness, setback viscosity, and peak time. Acceptable sweet potato “amala” with average sensory acceptability score of 7.5 were obtained from yellow-fleshed varieties irrespective of the processing method. Flour that produced acceptable “amala” were characterized by lower values of protein (2.20–3.94%), fiber (1.30–1.65%), total sugar (12.41–38.83 lg/mg), water absorption capacity (168–215 g/100 g), water solubility (8.29–14.65%), swelling power (0.52–0.82 g/g), and higher peak time (6.9–8.7 min)

Characteristics of traditionally processed shea kernels and butter

The traditional production of shea butter requires a heat treatment of the nuts. This study compared the end products derived by two commonly used heat treatments, namely smoking and boiling followed by sun-drying. Neither treatment influenced the moisture content of the kernels (8–10%), but the boiling treatment resulted in more free fatty acids (FFA) (6%) and a higher fat content (41%) of kernels. A sensory panel preferred shea butter from boiled kernels because of its soft texture and intense smell. This butter also had the highest values for moisture content (2%), unsaponifiable matter (7%), tocopherol compounds (125 mg g-1), peroxide value (8 meq O2 kg-1), iodine value (53 mg I2 100 g-1) and FFA (2%). Minor variations were noticed in the fatty acid profile. Aside from the use of butter from both boiled and smoked kernels in cosmetics, the butter from smoked kernels will be more suitable for food purposes

Characteristics of traditionally processed shea kernels and butter

The traditional production of shea butter requires a heat treatment of the nuts. This study compared the end products derived by two commonly used heat treatments, namely smoking and boiling followed by sun-drying. Neither treatment influenced the moisture content of the kernels (8–10%), but the boiling treatment resulted in more free fatty acids (FFA) (6%) and a higher fat content (41%) of kernels. A sensory panel preferred shea butter from boiled kernels because of its soft texture and intense smell. This butter also had the highest values for moisture content (2%), unsaponifiable matter (7%), tocopherol compounds (125 mg g-1), peroxide value (8 meq O2 kg-1), iodine value (53 mg I2 100 g-1) and FFA (2%). Minor variations were noticed in the fatty acid profile. Aside from the use of butter from both boiled and smoked kernels in cosmetics, the butter from smoked kernels will be more suitable for food purposes

Influence of Roasting of Shea Kernels on Their Fat Content and Some Quality Characteristics of Shea Butter

In shea production zones in Sub-Saharan Africa, shea butter is mostly produced by women using traditional methods. Improvement of their practices would allow them to obtain better monetary returns for their activities. Roasting of crushed shea kernels is a processing step that has a major influence on the quantity and quality of extracted shea butter. Using a central composite face-centered design (CCFD), the effect of roasting, specifically roasting time and temperature was investigated. Both factors influenced fat content (44-53% dw) of the crushed kernels; colour characteristics and free fatty acid (FFA) content (0.5-3%) of the butter. In shea butter from differently roasted kernels, 58 volatile compounds were identified, of which 11 were quantitatively dominant, against 27 compounds in butter from unroasted kernels. The ideal practice according to the CCFD model is roasting at 171 ºC for 15 min, which resulted in a fat content of 49% dw of the kernels, a butter yield of 32%, a FFA of 1.2% of the butter, and a peroxide value of 3.2 meq O2/kg. This optimum roasting time is appreciably shorter than the current practice, suggesting that the use of firewood during traditional processing can be reduced

Influence of Roasting of Shea Kernels on Their Fat Content and Some Quality Characteristics of Shea Butter

In shea production zones in Sub-Saharan Africa, shea butter is mostly produced by women using traditional methods. Improvement of their practices would allow them to obtain better monetary returns for their activities. Roasting of crushed shea kernels is a processing step that has a major influence on the quantity and quality of extracted shea butter. Using a central composite face-centered design (CCFD), the effect of roasting, specifically roasting time and temperature was investigated. Both factors influenced fat content (44-53% dw) of the crushed kernels; colour characteristics and free fatty acid (FFA) content (0.5-3%) of the butter. In shea butter from differently roasted kernels, 58 volatile compounds were identified, of which 11 were quantitatively dominant, against 27 compounds in butter from unroasted kernels. The ideal practice according to the CCFD model is roasting at 171 ºC for 15 min, which resulted in a fat content of 49% dw of the kernels, a butter yield of 32%, a FFA of 1.2% of the butter, and a peroxide value of 3.2 meq O2/kg. This optimum roasting time is appreciably shorter than the current practice, suggesting that the use of firewood during traditional processing can be reduced