347 research outputs found
Proximate composition of traditional local sorghum beer “dolo” manufactured in Ouagadougou
Dolo is a local beer manufactured from malted sorghum grains. It is the most commonly consumed alcoholic beverage in Burkina Faso (60% of population). Thirty (30) samples of dolo were collected from local markets in Ouagadougou and analyzed with respect to their proximate compositions and pH values using biochemical standard method. The average values of pH, dry matter and insoluble matter among samples were respectively 3.50±0.07, 5.90±1.24% (w/v) and 0.85±0.32% (w/v). Alcohol content in dolo samples was on average 2.30±0.25% (v/v). The total proteins, total carbohydrates and reducing sugars were 26±14.8, 38±20.4 and 10±3.8 μg/ml, respectively. The lipids were detected as traces in all dolo samples. The energetic value of dolo was on average 21.8±1.6 Kcal/100 ml of which these parameters characterize the quality of dolo.Keywords: Sorghum bicolor, local beer, dolo, alcohol content, composition, Burkina FasoAfrican Journal of Biotechnology Vol. 12(13), pp. 1517-152
Optimization of Aqueous Extraction of Anthocyanins from Hibiscus sabdariffa L. Calyces for Food Application
Aqueous extracts of Hibiscus sabdariffa calyces are worldwide used for the production of several products such as polyphenolic-antioxidant containing beverages. However, optima conditions for extraction of polyphenolics such as anthocyanins from this plant species were unknown. For this, the influence of particle size and calyx/water ratio on the anthocyanins extraction and biochemical composition during extraction were investigated using bright red and dark red Hibiscus sabdariffa calyces.Results showed that the pH of the bright red calyces was 2.24 ± 0.01 corresponding to 12.66 ± 0.15 g/100g dry weight (DW) titratable acidity equivalent of malic acid. The pH of the dark red calyces was 2.15 ± 0.01 corresponding to 15.44 ± 0.15 g/100g DW titratable acidity equivalent malic acid. Total sugars content was 3.24±0.04 and 3.13±0.06 g/100g DW for bright red and dark red, respectively. Proteins content ranged from 4.56 ± 0.04 to 6.96 ± 0.17 g/100g DW. The level of the total phenols ranged from 3.82 ± 0.33 to 5.22 ± 0.08 g/100g DW. Average anthocyanins content was 2.61 ± 0.11 and 2.98 ± 0.02 g/100g DW for dark red and bright red calyces, respectively. Calyces were found to show an antioxidant capacity of up to 300 µmolTrolox equivalent/100g. For all calyx/water ratios, the anthocyanins content increased with extraction time till 60 min and remained almost stable thereafter.The optimization of the aqueous extraction was obtained at the ratio 1/10 (calyx/water) for the production of roselle concentrated extract, using calyces size less than 250 µm,at 30°C, for one hour percolation. Keywords: Hibiscus sabdariffa L, anthocyanins water, calyx/water ratio, particle size, optimization, extraction
Diversité des insectes actifs au sol dans quatre écosystèmes de bas-fonds du Burkina Faso : importance pour la détermination de bio-indicateurs caractérisant ces milieux
L'action de l’Homme sur l'environnement peut affecter la diversité biologique qui à son tour peut être utilisée comme indicateur de la santé des écosystèmes. Une étude a été menée en 2006 dans quatre (4) MicroBassin-Versants (MBV) du Burkina Faso pour évaluer la diversité des insectes rampants au sol et caractériser chaque écosystème par ses bio-indicateurs les plus significatifs. La diversité taxonomique des espècesd’insectes capturées dans différents sites par des pièges de Barber, leur distribution et leur abondance relative au début et à la fin de la saison des pluies ont ainsi été déterminées. Quatre (4) ordres regroupant treize (13)familles d’insectes, les Carabidae, les Scarabaeidae, les Tenebrionidae, les Cétonidae, les Cérambycidae, les Curculionidae, les Hydrophilidae, les Elateridae, les Staphylinidae, les Chrysomelidae (Coléoptères), lesFormicidae (Hyménoptères), les Gryllidae (Orthoptères) et les Labiduridae (Dermaptères), ont été identifiées dans les MBV étudiés. Les variations climatiques influencent la diversité taxonomique des insectes qui fluctuepar ailleurs dans l’espace et dans le temps. Cinq (5) familles, les Formicidae, les Cicindellidae, les Carabidae, les Scarabaeidae et les Tenebrionidae ont été les plus abondantes et les plus diversifiées en espèces dans chacun des quatre MBV. Ces taxa, qui se sont adaptés aux écosystèmes étudiés, en sont probablement les meilleurs indicateurs. Les résultats obtenus sont discutés en vue de déterminer comment ces groupes majeurs peuvent être utilisés dans l’évaluation et la gestion des écosystèmes qu’ils peuplent
Caractéristiques physicochimiques de quelques matières premières utilisées dans la formulation des aliments pour volaille au Burkina Faso
Objectifs : Connaitre la composition physicochimique des matières premières les plus utilisées dans la formulation des aliments pour volaille.Méthodologie et Résultats : Une étude prospective a permis de répertorier les matières alimentaires les plus utilisées pour l’alimentation de volaille au Burkina Faso. Les principaux constituants ont été déterminés par les méthodes AOAC. Les acides aminés et les minéraux ont été déterminés respectivement par la chromatographie et la spectrométrie à flamme. Les résultats ont montré des proportions massiques (g/100g MS) comprises entre 9,17±0,13 et 59,9±0,27 pour les protéines, 2,24±0,10 et 15,56±0,03 pour les lipides,4,16±0,04 et 73,8±0,07 pour les carbohydrates totaux, entre 6,04±0,13 et 14,53±0,07 pour la cellulose, 0,01±0,00 et 34,03±0,07 pour le calcium, 0,02±0,07 et 18,01±0,00 pour le phosphore. Les teneurs enméthionine, lysine, thréonine étaient respectivement comprises entre 0,19±0,02 et 1,49±0,03 ; 0,25±0,06 et 2,38±0,03, et 0,30±0,03 et 2,32±0,03.Conclusion et application des résultats: Il ressort de cette étude que la farine de poisson présente les teneurs les plus élevées en protéine (59,9± 0,27 g/100g), calcium (6,42± 0,04 g/100g) et phosphore (3,88± 0,06 g/100g). Le soja est le plus riche en matière grasse (17,98± 0,10 g/100g) et le maïs jaune est le plus riche en glucide (73,8± 0,07 g/100g). Ces données produites peuvent servir à l’établissement de tables de composition des matières premières locales utilisables dans l’alimentation de volaille et leur vulgarisationauprès des aviculteurs leur permettra de mieux s’orienter dans le choix des ingrédients de hautes valeurs nutritionnelles et de réduire le coût de la formulation.
Objectives: To know the physicochemical composition of the raw materials mostly used in the formulation of poultry feed.Methodology and Results: A prospective study was carried out to identify the most commonly used feed materials for poultry feed in Burkina Faso. The main constituents were determined by AOAC methods. Amino acids and minerals were determined respectively by chromatography and flame spectrometry. Results showed mass proportions (g / 100g DM) between 9.17 ± 0.13 and 59.9 ± 0.27 for proteins, 2.24 ± 0.10 and 15.56 ± 0.03 for lipids, 4.16 ± 0.04 and 73.8 ± 0.07 for total carbohydrates, 6.04 ± 0.13 and 14.53 ± 0.07 for cellulose, 0.01 ± 0.00 and 34.03 ± 0.07 for calcium, 0.02 ± 0.07 and 18.01 ± 0.00 for phosphorus. Content in essential amino acids such as methionine, lysine, and threonine ranged between 0.19 ± 0.02 and 1.49 ± 0.03, 0.25 ± 0.06 and 2.38 ± 0.03, and 0.30 ± 0.03 and 2.32 ± 0.03, respectively.Conclusion and application of results: It emerges from this study that fishmeal has the highest contents of protein (59.9 ± 0.27 g/100g), calcium (6.42 ± 0.04 g/100g) and phosphorus (3.88 ± 0.06 g/100g). Soy is the richest in fat (17.98 ± 0.10 g/100g) and yellow corn is the richest in carbohydrate (73.8 ± 0.07 g/100g). These data produced can be used to establish composition tables for local raw materials that can be used in poultry feed and their popularization with poultry farmers will allow them to better orient themselves in the choice of ingredients with high nutritional values and reduce the cost of formulation
Phenolic compounds and related enzymes as determinants of sorghum for food use
Phenolic compounds and related enzymes such as phenol biosynthesizing enzymes (phenylalanine ammonia lyase) and phenol catabolizing enzymes (polyphenol oxidase and peroxidase) are determinants for sorghum utilization as human food because they influence product properties during and after sorghum processing. Phenolic compounds are quality-grade markers for the preparation of several foods because of enzyme inhibitory activities, color, or antioxidant activities. Large inter-varietal differences in contents of phenolic compounds and their antioxidant activities among sorghum varieties exist. Moreover, some red sorghum varieties have higher antioxidant activities than the most important sources of natural antioxidants. Oxidation products of peroxidase and polyphenol oxidase (benzoquinones and polymeric compounds) affect food quality. This paper reviews the current advances in phenolic compounds and phenolic enzymes in sorghum as human food, with emphasis on nutritional and health aspects. The suitability of sorghum varieties for food and beverages is discussed
Sorghum grain as human food in Africa: relevance of content of starch and amylase activities
Sorghum is a staple food grain in many semi-arid and tropic areas of the world, notably in Sub-Saharan Africa because of its good adaptation to hard environments and its good yield of production. Among important biochemical components for sorghum processing are levels of starch (amylose and amylopectin) and starch depolymerizing enzymes. Current research focus on identifying varieties meeting specific agricultural and food requirements from the great biodiversity of sorghums to insure food security. Results show that some sorghums are rich sources of micronutrients (minerals and vitamins) and macronutrients (carbohydrates, proteins and fat). Sorghum has a resistant starch, which makes it interesting for obese and diabetic people. In addition, sorghum may be an alternative food for people who are allergic to gluten. Malts of some sorghum varieties display a-amylase and ß-amylase activities comparable to those of barley, making them useful for various agro-industrial foods. The feature of sorghum as a food in developing as well as in developed countries is discussed. A particular emphasis is made on the impact of starch and starch degrading enzymes in the use of sorghum for some African foods, e.g. “tô”, thin porridges for infants, granulated foods “couscous”, local beer “dolo”, as well agro-industrial foods such as lager beer and bread.Keywords: sorghum, a-amylase, b-amylase, starch, infant porridge, beer, couscous, dolo, tô, brea
Comparison of phenolic compounds and antioxidant capacities of traditional sorghum beers with other alcoholic beverages
Thirty samples of sorghum beers “dolo” were selected from traditionally fermented household manufacturers from Burkina Faso. Dolo samples were screened for their total phenolic content, proanthocyanidins and putative antioxidant capacities, and were compared with industrial beers and wines. Total phenols were measured using the Folin-Ciocalteu method. Proanthocyanidins content were determined by the method of HCl-butanol hydrolysis. Antioxidant activities were evaluated both with 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and by the trolox equivalent antioxidant capacity (TEAC) using 2,2’-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid radical) (ABTS•+). The average contents of total phenols and proanthocyanidins were 506 μg GAE/ml of dolo and 45 μg APE/ml of dolo, respectively. An average antioxidant capacity was found in 148 μmol of TEAC per litre of dolo or 2.2 μmol of TEAC per gram of dolo. Proanthocyanidins in dolo represent on average, 10% of total phenolic content. Results also showed that the red wines from different brands had higher levels of phenolic content and antioxidant capacities than dolo. Nevertheless, dolo displays higher levels of total phenolic content than lager beers and white wines. Sorghum grains as well as their derived food-products such as local beers are good sources of bioactive compounds comparable to other industrial alcoholic beverages.Keywords: Sorghum bicolor, dolo, beer, total phenols, proanthocyanidins, antioxidant capacit
Near-forward Raman selection rules of the phonon-polariton created by alloying in (Zn,Be)Se
The Raman selection rules of the (ZnSe, BeSe) mixed phonon polariton created
by alloying in the three mode (1ZnSe, 2BeSe) ZnBeSe system, whose dramatic S
like dispersion covers the large frequency gap between the ZnSe and BeSe
spectral ranges, is studied in its wave vector dependence by near forward
scattering. Both the collapse regime away from the Brillouin zone centre and
the reinforcement regime near the Brillouin zone centre are addressed, using
appropriate laser lines and Be contents. We find that in both regimes the
considered phonon polariton, in fact a transverse mode with mixed mechanical
and electrical character, obeys the same nominal Raman selection rules as its
purely mechanical variant commonly observed in the backscattering geometry.
Besides, marked differences in the phonon polariton Raman lineshapes in the two
regimes give a hint about how the phonon polariton electrical field E develops
while descending the S like dispersion towards the Brillouin zone centre. In
the reinforcement regime E is large, leading to intramode on top of intermode
transfers of oscillator strength mediated by E between the two BeSe modes, that
both exhibit a fine structure on account of the alloy disorder. In contrast, in
the collapse regime E remains weak, as testified by the absence of intramode
transfer. The discussion is supported by contour modeling of the multi phonon
polariton Raman lineshapes in their wave vector dependence within the linear
dielectric approach.Comment: 16 pages, 7 figure
The implementation of malaria intermittent preventive trialtreatment with sulphadoxine-pyrimethamine in infants reduced all-cause mortality in the district of Kolokani, Mali: results from a cluster randomized control
Percent Fat Mass Increases with Recovery, But Does Not Vary According to Dietary Therapy in Young Malian Children Treated for Moderate Acute Malnutrition.
BackgroundModerate acute malnutrition (MAM) affects 34.1 million children globally. Treatment effectiveness is generally determined by the amount and rate of weight gain. Body composition (BC) assessment provides more detailed information on nutritional stores and the type of tissue accrual than traditional weight measurements alone.ObjectiveThe aim of this study was to compare the change in percentage fat mass (%FM) and other BC parameters among young Malian children with MAM according to receipt of 1 of 4 dietary supplements, and recovery status at the end of the 12-wk intervention period.MethodsBC was assessed using the deuterium oxide dilution method in a subgroup of 286 children aged 6-35 mo who participated in a 12-wk community-based, cluster-randomized effectiveness trial of 4 dietary supplements for the treatment of MAM: 1) lipid-based, ready-to-use supplementary food (RUSF); 2) special corn-soy blend "plus plus" (CSB++); 3) locally processed, fortified flour (MI); or 4) locally milled flours plus oil, sugar, and micronutrient powder (LMF). Multivariate linear regression modeling was used to evaluate change in BC parameters by treatment group and recovery status.ResultsMean ± SD %FM at baseline was 28.6% ± 5.32%. Change in %FM did not vary between groups. Children who received RUSF vs. MI gained more (mean; 95% CI) weight (1.43; 1.13, 1.74 kg compared with 0.84; 0.66, 1.03 kg; P = 0.02), FM (0.70; 0.45, 0.96 kg compared with 0.20; 0.05, 0.36 kg; P = 0.01), and weight-for-length z score (1.23; 0.79, 1.54 compared with 0.49; 0.34, 0.71; P = 0.03). Children who recovered from MAM exhibited greater increases in all BC parameters, including %FM, than children who did not recover.ConclusionsIn this study population, children had higher than expected %FM at baseline. There were no differences in %FM change between groups. International BC reference data are needed to assess the utility of BC assessment in community-based management of acute malnutrition programs. This trial was registered at clinicaltrials.gov as NCT01015950
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