Physicochemical and nutritional properties of rice as affected by parboiling steaming time at atmospheric pressure and variety

To elucidate the effect of different parboiling steaming time on the physicochemical and nutritional quality of rice, four varieties, NERICA1, NERICA7, IR841, and WITA4, were soaked at the same initial temperature (85°C) and steamed for 5, 15, 25, 35, and 45 min. NERICA7 steamed for 25 min recorded the highest head rice yield (71.9%). Nonparboiled IR841 recorded the shortest cooking time (17.0 min), while NERICA1 steamed for 35 min recorded the longest cooking time (26.1 min). NERICA1 steamed for 45 min was the hardest (63.2 N), while nonparboiled IR841 was the softest (28.7 N). NERICA7 recorded higher peak and final viscosities across all steaming times compared to the other varieties. NERICA7 steamed for 35 and 45 min recorded the lowest total starch (77.3%) and the highest protein (13.2%) content, respectively. NERICA7 steamed for 25 and 45 min recorded the highest phosphorus (0.166%), magnesium (572 mg/kg), and potassium (2290 mg/kg) content, respectively. We conclude that, depending on desired physicochemical and nutritional properties, specific varieties and steaming times can be selected to achieve those outcomes

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

Appropriate parboiling steaming time at atmospheric pressure and variety to produce rice with weak digestive properties

Consumers with diabetes mellitus have shown interest in products with low postprandial glucose. To produce rice for this group of consumers, the effect of parboiling steaming time (0, 5, 15, 25, 35, and 45 min) and variety (NERICA1, NERICA7, WITA4, and IR841) on resistant, damaged starch fractions and glycemic response in rats was investigated. Resistant and damaged starch fractions were influenced by variety and steaming time but this was not the case for glycemic index. Nonparboiled NERICA7 and NERICA7 steamed for 25 min recorded the highest (10.07%) and lowest (2.49%) resistant starch fraction, respectively. Resistant starch correlated negatively with protein and sodium and positively with lipids. Damaged starch was high for WITA4 steamed for 45 min (26.80%) and low for nonparboiled NERICA1 (6.59%). Damaged starch correlated positively with lipid content and negatively with ash and total starch content. NERICA7 steamed for 35 min recorded the lowest postprandial glucose level 30 min after feeding (0.16 g/L), while WITA4 steamed for 15, 25, and 35 min and nonparboiled NERICA7 recorded higher levels (0.76, 0.91, 0.84, and 0.76 g/L, respectively). NERICA7 steamed for 35 min recorded both low glycemic and weak digestive properties because the glycemic index was lowest 120 min and increased steadily up to 180 min after feeding. We conclude that the digestive properties of rice depend both on the intrinsic properties of the variety and the parboiling steaming time

Relationships between anthocyanins and other compounds and sensory acceptability of Hibiscus drinks

Chemical composition of Hibiscus drinks (Koor and Vimto varieties, commercial and traditional, infusions and syrups) was related to sensory evaluation and acceptance. Significant correlations between chemical composition and sensory perception of drinks were found (i.e. anthocyanin content and Hibiscus taste). Consumers (n=160) evaluated drink acceptability on a 9-point verbal hedonic scale. Three classes of behaviour were identified: a) those who preferred syrup (43% of consumers); b) those who preferred infusion (36%); and c) those who preferred all of the samples (21%). Acceptability of ‘syrup likers‘ was positively correlated to sweet taste, reducing sugar content and inversely correlated to acidic taste and titrable acidity. Acceptability of ‘infusion likers’ was positively correlated to the taste of Hibiscus drink and anthocyanin content. The study shows that the distinctions between the acceptability groups are very clear with respect to the chemical composition and rating of sensory attributes

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)

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

Effect of organic and mineral fertilization on proximate composition of three leafy vegetables harvested at different periods

Leafy vegetables are part of natural resources traditionally harvested from forests in Benin. Some of these wild plants foods have been introduced in the small scale production system. The low productivity and the increasing demand for such products urged to use fertilizers. However, the impact of such practices on the nutritional properties of these leaves was poorly documented. In this study Sesamum radiatum, Ceratotheca sesamoïdes and Justicia tenella were cultivated using NPK, cowpat and mixture of NPK plus cowpat. Leaves harvested at 6, 9, 10, 12 or 14 weeks after transplanting were analyzed for proximate composition. Protein content ranged from 17.2 to 33.8 g/100 g DW; ash from 7.7 to 20.4 g/100 g; fat from 1.2 to 7.3 g/100 g, fiber from 5.6 to 13.1 g/100 g and polyphenols content from 0.24 to 1.33 g GAE/100 g (DW). Significant effects of species, fertilizer and cutting time were evidenced. Whereas ash content increased by 1 to 25.8% ratio in fertilized S. radiatum leaves, it showed a downward trend (-1 to -22%) during the two first cutting times of C. sesamoides followed by an upward trend (12.7 to 14.3%) at the last cutting time, in comparison to the non fertilized leaves. © 2013 International Formulae Group. All rights reserved.Keywords: Fertilization, composition, Sesamum radiatum, Ceratotheca sesamoides, Justicia tenell

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 &gt; 0.05) was observed between proximate composition of the samples fermented without additives and those fermented with additives.Keywords: Fermentation, Bacillus, softening effect, softenin

Study of a post-column synchronous fluorescence derivatization to analyze phytates in foods by chromatography

Phytates (myo-inositol-1,2,3,4,5,6-hexakisphosphate or InsP6) is the storage form of about 80% of total phosphorus in foods. They are commonly referred to antinutritional compounds because they strongly chelate with divalent cations such as iron, potassium, calcium, magnesium, zinc and copper, impeding their absorption. Their nutritional effects and physiological functions are dependent on the number and the position of the phosphate groups on the myo-inositol ring (InsP1 to 6). However, the lack of analysis method accurate and reliable to quantify each form creates the need to develop new approaches. In this study, a chromatographic methodology (HPLC) was developed and enhanced to separate and quantify the six forms of myo-inositol polyphosphates using synchronous fluorescence by post-column derivatization. Maximization of reagents content and assays were realized in static and dynamic step, and standards were bought pure from Larodan (USA). The HPLC (Agilent infinity II – Fluorescence/Diode Array Detectors) was improved with a supplementary pump for post-column derivatization through a knitted open tubular (KOT) reactor. Results indicated that this innovative method crossing HPLC and synchronous fluorescence of iron-phenanthroline (0.0045 mol/L FeCl3•6H2O: 0.0085 mol/L phenanthroline) with a post-column derivatization is promising and fast for phytates separation and quantification. Indeed, the quenching of phenanthroline caused by the presence of iron was canceled when InsP eluted through a separation by ion-pair reverse chromatography (44% 0.035M formic acid mixed with 56% methanol and 1% tetrabutylammonium hydroxide fixed at pH 4.3 adjusted with H2SO4 72%). It allowed an increase of the detection limits of InsP compare to conventional refractometer (RID). It seemed that using the same phase for InsP extraction could simplify the process route by avoiding unitary operations such as evaporation, purification or concentration compared to classical extraction. Methanol fraction contained in the solvent might be able to slow or stop enzymatic and non-enzymatic hydrolyses of InsP during extraction, stabilizing the extract environment too. This innovative analytical approach to separate and quantify phytates by HPLC seemed robust and reliable. Additional assays need to be performed to determine the applicability of the method in multiple food environment and evaluate phytate subsequent impact on divalent minerals' bioavailability