30 research outputs found
Reduction of the cyanide content during fermentation of cassava roots and leaves to produce bikedi and ntoba mbodi, two food products from Congo
Cassava roots and leaves constitute energy-rich and protein-rich foods, respectively, for the populations in Central Africa, where they are consumed as staple foods. But cassava roots and leaves contain some cyanide in the form of cyanogenic glucosides, notably the linamarine, which can constitute a poison for the consumers when roots or leaves are processed improperly. Cassava roots and leaves processing in Congo, as in most central African countries, involve fermentation. The fermentation of the cassava roots is a lactic fermentation (pH 3.8) with Lactobacillus as dominant microflora whereas that of the cassava leaves is an alkaline fermentation (pH 8.5) where Bacillus constitute the main microflora. The hydrolysis of cyanogenic glucosides takes place as well in acid medium during the cassava tubers fermentation as in basic medium with the cassava leaves fermentation. The cyanide content decreases during the fermentation of cassava roots and leaves by more than 70% through the activities of the bacterial produced linamarase, allowing the hydrolysis of cyanogenic glucosides. Certain lactic bacteria present in the environment of fermentation are resistant to the strong cyanide concentrations of between 200 and 800 ppm.African Journal of Biotechnology Vol. 4 (7), pp. 689-696, 200
RÉGÉNÉRATION IN VITRO DE L’ARBRE À SUIF (PENTADESMA BUTYRACEA SABINE), UNE ESPÈCE LIGNEUSE À USAGES MULTIPLES (LUM) VULNÉRABLE AU BENIN
This work is done in order to identify the effects of basal media associated with two cytokinins (BAP and zeatin) and suitability for the regeneration of apical and axillary buds Pentadesma butyracea. Fragments axillary bud stem and apical bud stem fragment were taken from seedlings P. butyracea from seed germination in a greenhouse. After disinfection, explants were cultured on three basic areas: MS (Murashige and Skoog), B5 (Ganborg) and WPM (Woody Plant Medium). The effects of Zeatin and BAP on the bud and bud development were also studied. These in vitro propagation of tests conducted in this species, showed that the apical bud fragments proved to be the most favorable. Among the tested culture media, basal medium Gamborg (B5) is most suited to the entry into operation of apical buds (26.66%). Other WPM and MS basal media also allowed bud but at low rates (20%; 13%). Zeatin (3.5 mg / L) appears best suited to budding and regeneration of apical buds of P. butyracea and the formation of leaves per explants. BAP favored the resumption of activity of the apex, but not plant development. Our experiments allow to open a new path consistent multiplication of individuals elites Pentadesma butyracae to produce seeds that can be used for propagation, domestication and conservation of this species
RÉGÉNÉRATION IN VITRO DE L’ARBRE À SUIF (PENTADESMA BUTYRACEA SABINE), UNE ESPÈCE LIGNEUSE À USAGES MULTIPLES (LUM) VULNÉRABLE AU BENIN
This work is done in order to identify the effects of basal media associated with two cytokinins (BAP and zeatin) and suitability for the regeneration of apical and axillary buds Pentadesma butyracea. Fragments axillary bud stem and apical bud stem fragment were taken from seedlings P. butyracea from seed germination in a greenhouse. After disinfection, explants were cultured on three basic areas: MS (Murashige and Skoog), B5 (Ganborg) and WPM (Woody Plant Medium). The effects of Zeatin and BAP on the bud and bud development were also studied. These in vitro propagation of tests conducted in this species, showed that the apical bud fragments proved to be the most favorable. Among the tested culture media, basal medium Gamborg (B5) is most suited to the entry into operation of apical buds (26.66%). Other WPM and MS basal media also allowed bud but at low rates (20%; 13%). Zeatin (3.5 mg / L) appears best suited to budding and regeneration of apical buds of P. butyracea and the formation of leaves per explants. BAP favored the resumption of activity of the apex, but not plant development. Our experiments allow to open a new path consistent multiplication of individuals elites Pentadesma butyracae to produce seeds that can be used for propagation, domestication and conservation of this species
Nutritional properties of enriched local complementary flours
Abstract: This study aimed to identify the nutritional, functional, sensory and microbiological profile of experimental nutritional flours, produced with local products in Burkina Faso. The raw materials included maize (Zea mays), millet (Pennisetum glaucum) and rice (Oryza sativa). Local ingredients were pulps of Adansonia digitata and Parkia biglobosa and seeds of Cucurbita maxima and Moringa oleifera. Three formula were developed, the first (F1) with maize, the second (F2) with rice and the last (F3) with millet. Each of these cereals was mixed with predetermined portions of seeds and pulps in order to obtain enriched flour. Nutritional, microbiological and functional analysis and the acceptability criteria of these enriched flours were assessed and compared to Misola (F4), the existing local complementary flour. The fat content of experimental flours were respectively in the first (F1), second (F2) and third formula (F3) 15.91±0.01%, 11.82±0.02% and 17.02±0.02%. The carbohydrate range was 65.46±0.06%, 70.81±0.01% and 64.51±0.01% for F1, F2 and F3, while the energetic value is higher than recommended (453.07±0.05, 424.56±0.03 and 458.96±0.05 kcal respectively for F1, F2 and F3). Functional characteristics indicated the good viscosity (117, 119 and 121 mm/30 sec for F1, F2 and F3) least gelation (9, 6 and 7%) and water absorption capacity (2, 4 and 1 g/g). Trained sensory evaluation panellists gore the enriched flour porridge a score of acceptable. These enriched flours have great potential as a weaning food in resource-poor and technologically under-developed countries
Comparison of the microbial composition of African fermented foods using amplicon sequencing
Fermented foods play a major role in the diet of people in Africa, where a wide variety of raw materials
are fermented. Understanding the microbial populations of these products would help in the design of
specific starter cultures to produce standardized and safer foods. In this study, the bacterial diversity of
African fermented foods produced from several raw materials (cereals, milk, cassava, honey, palm sap,
and locust beans) under different conditions (household, small commercial producers or laboratory) in 8
African countries was analysed by 16S rRNA gene amplicon sequencing during the Workshop “Analysis
of the Microbiomes of Naturally Fermented Foods Training Course”. Results show that lactobacilli
were less abundant in fermentations performed under laboratory conditions compared to artisanal or
commercial fermentations. Excluding the samples produced under laboratory conditions, lactobacilli
is one of the dominant groups in all the remaining samples. Genera within the order Lactobacillales
dominated dairy, cereal and cassava fermentations. Genera within the order Lactobacillales, and genera
Zymomonas and Bacillus were predominant in alcoholic beverages, whereas Bacillus and Lactobacillus
were the dominant genera in the locust bean sample. The genus Zymomonas was reported for the first
time in dairy, cereal, cassava and locust bean fermentations
Handling practices, quality and loss estimation along the value chain of waragashi, a soft cheese from Benin
Waragashi is a soft cheese made from cow milk, widely marketed and consumed in Benin and in other African countries (Nigeria, Ghana, Togo). However, the product is prone to deterioration, especially at ambient temperature (28–32°C) because of its high water activity, nutrients and neutral pH. The present study aimed at getting insight into the factors affecting the quality of waragashi and estimating losses along the value chain. The entire value chain was investigated (i) to determine the product handling conditions, and (ii) to determine stakeholders’ perceptions of related quality, and (iii) to estimate the product proportion and quality loss along the value chain. One hundred and ninety-nine (199) producers, 100 collectors, 156 wholesalers/retailers, and 326 consumers were randomly interviewed in the main Departments of Benin involved in this soft cheese value chain. Descriptive statistics and chi-square tests were used as statistic tools for highlighting the relationships between variables. Significance was accepted at a P value of 0.05. The results showed that waragashi, produced and sold essentially by women (≥ 97%), is packed in bowls (78.9% of respondents) and plastic boxes (16.1% of respondents) as containers at the production stage and marketing. Daily boiling and soaking in water extract of dye sorghum panicle (traditional red biocolorant used to colour the product) were used as the main preservation methods. Waragashi was held mainly at ambient temperature (28–32°C) along the value chain. The priority quality attributes of the product were texture, colour, and taste for producers, whereas texture, odour and appearance were the desirable attributes for consumers. The quality deterioration linked to inappropriate handling conditions occurred mostly at wholesalers/retailers’ level. This leads to important financial losses on the product varying from partial (reduction of approximately 30% of the sale price in comparison to that of the fresh product) to total loss of sale price, meaning that the product cannot be sold. Therefore, there is a need to find appropriate solutions to ensure a better-quality management of waragashi along the value chain
Effect of a multi-step preparation of amaranth and palm nut sauces on their carotenoid content and retinol activity equivalent values
The preparation of a traditional sauce based on amaranth leaves cooked palm nuts or red palm oil (RPO) in Benin was described. The recipes included an optional step of leaf blanching at 100 degrees C, heating the RPO or boiling the palm nuts and finally cooking all the ingredients together. The influence of this multi-step preparation on the carotenoid content of the final dish was measured. During blanching of amaranth leaves, violaxanthin was the only carotenoid to be significantly affected by the thermal treatment. Retinol activity equivalent (RAE) remained high after blanching even when alkaline traditional potash was added. Heating the RPO was the most critical step because it considerably and very rapidly (in <3 min) decreased a-carotene, beta-carotene and RAE values (more than 70%). Sauces calling for palm nuts, RPO and amaranth leaves were equally advantageous in terms of final RAE value. These ingredients and sauces can thus be used in programmes to reduce vitamin A deficiency