Propriétés rhéologiques de farines panifiables formulées à partir d’extraits d’amidon et de gluten de blé

Le présent travail a mis en évidence les propriétés rhéologiques des farines panifiables reconstituées avec des extraits d’amidon. Du gluten vital 10% a été incorporé à 90% d’extraits d’amidons de blé, de maïs,de riz et de la pomme de terre pour obtenir, respectivement, quatre (4) types de farines F1, F2, F3 et F4. Les farines ont été reconstituées à l’aide d’un mélangeur de type KENWOOD à 4 unités de vitesse. Les caractéristiques rhéologiques des pâtes des farines reconstituées ont été analysées à l’aide du Farinographe Brabender et de l’Alvéographe Chopin. Les farines F2, F3 et F4 sont caractérisées par une forte capacité d’hydratation, une faible activité a-amylasique qui se traduit par des temps de chute très élevés. Il en résulte des pâtes de très faible tenue avec une résistance à l’extraction, en comparaison avec une farine de référence (Fo). La force de la pâte de la farine F1 est plus élevée (W = 85.10-4 J) que celle des pâtes des farines F2, F3 et F4. Globalement, l’équilibre de configuration (P/L) entre la ténacité et l’élasticité des pâtes des farines est de l’ordre de 0,88 alors que les indices d’élasticité varient entre 7,3 et 9,4

Prevalence of Bacillus cereus and emetic strains detection from Ivory Coast local flours

Bacillus cereus is a pathogen associated with diarrheal and emetic food borne illness. However, in Africa, the prevalence of food borne infections attributable to this bacterium is difficult to establish accurately. Given the involvement of farinaceous foods in the majority of emetic outbreak and the dietary habits in Ivory Coast, implying an increase in the consumption of traditionally produced flours, the prevalence of Bacillus cereus and emetic strains associated to local flours produced in Abidjan were assessed. In this purpose, 100 samples of millet, maize and cassava flours were collected from five different Abidjan municipalities. Microbiological analysis were carried out in accordance with the standard EN ISO 7932 : 2004 and the European regulation EC 2073/2005, to enumerate the Bacillus cereus.. Bacillus cereus strains isolated were screened by polymerase chain reaction, for emetic strains detection. Overall, 31 (31 %) of maize, millet and cassava flours were positive for Bacillus cereus, at levels below 103 CFU/g. Comparing the five municipalities, the concentration of Bacillus cereus was not significantly different (P<0,05). Also, no significant  difference was observed, regardless of the types of flour analyzed. Furthermore, no potentially emetic toxin–producing strains were detected in this work.Keyword : Bacillus cereus, flour, pathogen, emetic strain. French Title: Prevalence de la detection de <i>Bacillus cereus</i> et de souches emetiques dans les farines locales de Cote d'Ivoire Bacillus cereus est un pathogène alimentaire responsable de toxi-infection diarrhéique et émétique. Le syndrome émétique est généralement associé aux aliments farineux. Compte tenu de l’implication des aliments farineux dans les toxi-infections émétiques et de la grande consommation de farines localement produites en Côte d’Ivoire, la prévalence de B. cereus a été évaluée dans cette denrée. 100 échantillons de farines de mil, de maïs et de manioc ont été collectés dans cinq communes d’Abidjan. Des  analyses microbiologiques ont été effectuées conformément à la norme EN ISO 7932: 2004 et à la réglementation européenne CE 2073/2005, afin de dénombrer les Bacillus Cereus et identifier les souches émétiques. Cet pathogène était présent dans 31 (31 % ) des farines de maïs, de mil et de manioc, à des concentrations inférieures à 103 UFC /g. Cette concentration n’est pas significativement différente (p <0,05), d’une commune à l’autre et aucune différence significative n’a été observée, quelque soit le type de farine analysé. Par ailleurs, aucune souche émétique n’a été détectée dans ces farines.Mots clés : Bacillus cereus, farine, pathogène, souche émétique.

Development of frozen-fried yam slices: Optimization of the processing conditions

The research performed on yam processing mainly concerns the production of crisps and flour. However, its transformation into deep-frozen French fries does not necessitate any other equipment than those used for potatoes. The industrial process of production of frozen French fries traditionally includes a pre-frying step. These steps contribute to the development of color and crispness, and the oil partially absorbed inhibits dehydration during the freezing step. The aim of this study was tooptimize frying conditions of deep-frozen fried yam (Dioscorea cayenensis var Kponan) slices. The effect of pre-frying time and temperature, final frying time and temperature on the oil uptake, texture, dry matter and colour of the fried yam slices has been studied. Frying conditions optimized with Box-Behnken experimental design were short pre-frying and frying conditions at high temperature characterized by prefryingtemperature at 157-170°C during 5-9s and frying temperature at 181-188°C for 2min 15s-2min 30s; or long pre-frying and frying conditions at low temperature characterized by pre-frying temperature at 150-158°C during 10-15s and frying temperature 170-177°C for 3-3min 15s. An adiabatic system was also developed by means of an insulator in which the core temperature of fried yam slices can be maintained constant at about 55°C after 15min of cooling, facilitating texture measurements at constant temperature. The present results may help in choosing the yam slices frying condition to be applied in order to achieve the desirable fried yamslices quality, required for protection against certain diseases like obesity. These models may also provide guidance as to how to control these quality parameters by altering four key environmental factors, pre-frying temperature and time and, final frying temperature and time. This process can also be commercialized and does not necessitate any other cost for equipment than those used for potatoes French fries and might be an interesting way of added value processing for this highly perishable yamtuber

Unpacking all-inclusive superordinate categories: Comparing correlates and consequences of global citizenship and human identities

Previous research suggests that all-inclusive superordinate categories, such as “citizens of the world” and “humans,” may represent different socio-psychological realities. Yet it remains unclear whether the use of different categories may account for different psychological processes and attitudinal or behavioral outcomes. Two studies extended previous research by comparing how these categories are cognitively represented, and their impact on intergroup helping from host communities toward migrants. In a correlational study, 168 nationals from 25 countries perceived the group of migrants as more prototypical of the superordinate category “citizens of the world” than their national group (relative outgroup prototypicality), whereas no differences in prototypicality occurred for the category “humans.” Identification with “citizens of the world” was positively associated with a disposition to oppose helping migrants and to offer dependency-oriented help. However, identification with “humans” was positively associated with helping in general, and with offering dependency- and autonomy-oriented help; and negatively associated with opposition to helping. The experimental study manipulated the salience of “citizens of the world” vs. “humans” vs. control category, among 224 nationals from 36 countries. Results showed that the salience of “humans” (vs. “citizens of the world”) triggered higher entitativity and essentialist perceptions, and dual-identity representations. No differences due to salience were found for representations of relative ingroup prototypicality or helping responses. Overall, these findings suggest that the interchangeable use of different labels is problematic, considering these might activate different representations, and thus, are likely to lead, in some circumstances, to different attitudinal or behavioral outcomes.info:eu-repo/semantics/publishedVersio

Chemical composition and antioxidant activity of essential oil, various organic extracts of Cistus ladanifer and Cistus libanotis growing in Eastern Morocco

In the present work, we studied the chemical composition of the essential oil of Cistus ladanifer and Cistus libanotis growing in Eastern Morocco. The essential oils were obtained by hydrodistillation and their chemical composition was analysed using gas chromatography- mass spectrometry (GC–MS). Camphene, borneol, cyclohexanol-2, 2, 6 tremethyl, terpineol-4 and α-pinene were the main constituents of the essential oil of C. ladanifer, while in the essential oil of C. libanotis we obtained terpineol-4, γ-terpinene, camphene, sabinene, α-terpinene and α-pinene. The antioxidant potential of various extracts (water, ethanol, ethanol: water (50:50), methanol, methanol: water (50:50), acetonitrile) and essential oils of C. ladanifer and C. libanotis were carried out by the method of 1,1-diphenyl-1-picrylhydrazylhydrate (DPPH) free radical scavenging. Total phenolic and flavonoid contents were determined. The result show that C. ladanifer of the leaves of methanol: water (50:50) extract had the highest value of total phenolic content and the lowest was present in ethanol: water (50:50) extract of the stem and acetonitrile extract of the flowers of C. libanotis. From our experimental results, the extract of flowers, fruit, stem and leaves of those plants showed highest potential as free radical scavengers.Keywords: Antioxidant, phenolics, flavonoids, essential oil, extracts, gas chromatography- mass spectrometry (GC–MS).African Journal of Biotechnology Vol. 12(34), pp. 5314-532

Assessment of fatty acids profile, oil yield and tocopherol content of four Almond cultivars grown in Eastern Morocco

The most cultivated varieties of almond in eastern Morocco: (Beldi (B), a local ecotype, Marcona (M) from Spain, Ferragnes-Ferraduel (F-F) and Fournat de Breznaud (FNB) from France), were studied during three consecutive crop years in order to evaluate variations in kernel oil yield, Fatty acid (FA) profile and physicochemical properties. For this purpose, extraction of almond oils was carried out by mechanical press. The yield of varieties B, M, (F-F) and FNB ranged between 50.68%- 54.33%, 41.46%- 52.59%, 47.70%-52.39% and 51.66%-56.10%, respectively. Oleic, linoleic and palmitic acids are the major fatty acids (FA) ranging between 57.54%- 72.90%, 17.80%- 29.81% and 6.50%-8.48%, respectively. Results showed a noticeable effect (P<0.001) of variety on Total phenolic content (TPC), oxidative stability and α-, β-, γ-, δ-tocopherol isomers; however, acidity and peroxide index, were affected with a lower manner by "variety" factor. In addition, all the analyzed parameters were highly (P<0.001) affected by climatic conditions of the crop year. In addition, the highest variations for the analyzed almond oils were recorded for their contents on α-tocopherol, γ-tocopherol, oleic and linoleic acids. According to the observed results, the couple Ferragnes-Ferraduel seems to produce stable and high quality almond oil compared to the other varieties

Optimización de la extracción de aceite de semilla de dátil mediante la ayuda de tecnologías hidrotermales y de ultrasonido

The date seed is a by-product from the date industry. Its use as a source of added-value compounds is of great interest. Oil accounts for 5-13% of the seed’s weight. Soxhlet extraction with organic solvents is the traditional method for obtaining oil from seeds. In this work, hydrothermal pre-treatments and sonication are proposed to make the extraction a more environmentally friendly process. Factors such as sonication time and temperature and hexane-to-seed ratio (H/S) have been considered. Response surface methodology was applied for optimization. Hydrothermal treatments increased oil recovery. H/S was the most influential factor, and was close to 7 mL/g seeds for both samples. 71% recovery was achieved for native seeds after 15 min sonication at 45 ºC, and 80% for 180 ºC-treated seeds after 45 min at 35 ºC when compared to Soxhlet extraction. These conditions comply with our initial aim. Pre-treatments seem to have a negative effect on oil stability, although this observation needs to be confirmed.La semilla de dátil es un subproducto de la industria datilera. Su uso como fuente de compuestos de valor añadido sería muy interesante. El aceite representa el 5-13% del peso de la semilla. La extracción mediante Soxhlet con disolventes orgánicos es el método tradicional para obtener aceite de semillas. En este trabajo se proponen pretratamientos hidrotérmicos y sonicación para diseñar un proceso de extracción más respetuoso con el medio ambiente. Se han considerado factores como el tiempo y la temperatura de sonicación y la proporción hexano/semilla (H/S). La optimización del proceso se llevó a cabo por el método de superficie de respuesta. Los tratamientos hidrotérmicos aumentaron el porcentaje de recuperación. El factor más influyente fue H/S, y su valor óptimo estuvo cerca de 7 mL/g para ambas muestras. La recuperación óptima fue del 71% para las semillas sin tratamiento tras 15 min de sonicación a 45 ºC, y del 80% para las semillas tratadas a 180 ºC después de 45 min a 35 ºC. Estos resultados cumplen con nuestro objetivo inicial. Sin embargo, los pretratamientos parecen tener un efecto negativo sobre la estabilidad del aceite, lo que se confirmará en estudios posteriores

Variability in almond oil chemical traits from traditional cultivars from eastern Morocco

In Morocco, cultivation of almond tree (Prunus amygdalus L.) constitutes the second most important plantation of fruit trees after olive growing. It is mostly cultivated in two regions, « Taza, Al Houceima Taounate » in the north and « Souss Massa Draa » in the south. Almond genetic resources (Marcoma, Fournat, Ferragnes/Ferraduel and Beldi), cultivated in eastern Morocco were studied during two consecutive crop years in order to evaluate variations in kernel oil yield, fatty acid profiles, oleic /linoleic (O/L) ratio and almond oils oxydative stability (OSI,evaluated by rancimat tests) in comparison to monovarietal olive oils. Almond kernel total oil (AO), Oleic acid (C18:1), Linoleic acid (C18:2), O/L-ratio, and tocopherol contents range between: 48 - 62% for kernel total oil; 65- 77.5% for C18:1; 17- 25% for C18:2; 2.5-4 for O/L ratio and 370 - 675 μg/g oil for tocopherols, respectively. We conclude that the genotype is the main variability source for all these chemical traits of AOs. Results obtained from Ferragnes/Ferraduel may be of interest for almond breeding focused to improve kernel oil yield and fatty acid profile. Besides, tocopherols contents of AOs seem to be the most important contributor for their stability to oxidation, even though compared to monovarietal olive oils, stability of AOs were very low and OSI value range between 20-27 hours. This fragility of AOs is due to their high content of unsaturated fatty acid which not allows their use for cooking or storage for long period. However, almond oils could have many applications in the food industry as in cosmeti