Identification of non-Saccharomyces yeast strains isolated from local traditional sorghum beer produced in Abidjan district (Côte d'Ivoire) and their ability to carry out alcoholic fermentation.

Studies on yeasts involved in traditional sorghum beer fermentation in several African countries revealed the presence of two groups: Saccharomyces and non-Saccharomyces. If Saccharomyces strains were reputed for their fermentation performances, the non-Saccharomyces yeast strains have been recognized for their contribution towards the improvement of the beverage's organoleptic quality, justifying their use as aromatic starter. In spite of this contribution, most studies were focused only on Saccharomyces strains as starter. In this work, the non-Saccharomyces yeast strains found in the inoculum of traditional sorghum beer was investigated. Identification of non-Saccharomyces yeast strains by PCR-RLFP followed sequencing of D1/D2 domain revealed the presence of 2 species: Issatckenkia orientalis and Pichia kudriavzevii with Issatckenkia orientalis predominating. Out of the two species, fermentation characteristics showed that Issatckenkia orientalis seemed suitable for sorghum beer production.

Volatile compounds of traditional sorghum beer (tchapalo) produced in Côte d'Ivoire: comparison between wild yeasts and pure culture of Saccharomyces cerevisiae.

In recent years, there had been growing demand for distinctive high quality beer. Fermentation management has a fundamental role in beer quality and the levels of aroma compounds. Use of non-conventional yeast has been proposed to enhance beer flavor. In this study, the bioflavor of traditional sorghum beer from Côte d'Ivoire was investigated. The flavor profile of two beers fermented with wild yeasts and with pure culture of Saccharomyces cerevisiae respectively were studied. The main flavor components of the beer fermented by pure culture of Saccharomyces cerevisiae were different from those of the beer fermented with wild yeasts. The total level of esters and higher alcohols were (173.51 and 128.85 mg/L) respectively in the beer fermented with wild yeasts. These levels were significantly higher than those in the beer fermented with pure culture of Saccharomyces cerevisiae which were 13.08 and 78.26 mg/L for higher alcohols and esters respectively. On the other hand, the beer fermented with pure culture of Saccharomyces cerevisiae had an acid content higher than beer fermented with wild yeasts, i.e. 9.3 mg/L and 7.53 mg/L respectively.

Contribution to the improvement of the nutritional and functional properties of bread by incorporating cinnamon powder (Cinnamomum verum).

Bread is a staple food for billions of households around the world; yet, some of its nutritional value is reduced during the manufacturing process. With this in mind, this work was carried out with the objective of improving the nutritional and functional properties of white bread by using cinnamon in breadmaking in order to contribute to the prevention of certain diseases related to eating habits. Therefore, bread-making trials by incorporating 0%, 0.5%, and 1% of cinnamon powder were carried out. From then on, the breads produced underwent physicochemical, biochemical, and organoleptic analyses. Thus, the results showed that the biochemical composition of the bread containing 1% cinnamon powder and the bread containing 0.5% cinnamon was 11.96 ± 0.02% and 11.22 ± 0.02% for protein, 1.70 ± 0.01% and 1.41 ± 0.07% for fiber, respectively, compared to 10.76 ± 0.014% protein and 1.36 ± 0.17% fiber for the bread without cinnamon. In terms of phytochemical composition, the bread containing 1% cinnamon powder recorded the highest contents of polyphenols, flavonoids, and condensed tannins (551.295 ± 25 µg EAG/g DM, respectively; 53.117 ± 1.36 µg EQ/g DM and 269.837 ± 39.2 µg EC/g DM) compared to the bread containing 0.5% of cinnamon powder and the bread with 1% cinnamon. From the nutritional and phytochemical point of view, the results of this work showed the positive impact of the incorporation of cinnamon powder in wheat flour-based bread with beneficial properties on the health of consumers.

Microbiological and Physicochemical Characteristics of Three Types of "Soumbara" from Seeds of African Locust Bean in Korhogo Markets, Côte d'Ivoire.

"Soumbara" is a fermented product sold in the markets of several West African countries. In the markets, it is sold in several formats (granulated, powder, and paste). The objective of this study was to evaluate the microbiological and physicochemical characteristics of these three types of "Soumbara" sold in the Korhogo markets. For this purpose, a preliminary survey followed by a sampling of 54 samples of "Soumbara" was carried out. The microorganism load count was carried out according to microbiological standards. The pH, titratable acidity, and moisture content were measured, respectively, with a pH meter, by dosing with sodium hydroxide solution and by differential weighing after passing the sample through the oven. The pH of the different samples is around 6. The moisture content is higher in "Soumbara" paste (20-24.7%) than in powdered (7.3-9.3%) and granulated (8.6-10.7%) "Soumbara." The acidity rates are between 0.07 and 0.13%, 0.2 and 0.3%, and 0.08 and 0.1%, respectively, for the granulated, powder, and paste types. Mesophilic aerobic germ loads (6.17-8.38 log10 cfu/g) for all three types of "Soumbara" are above the standard. Total coliform (1.13-2.96 log10 cfu/g), mould (0.86-2.52 log10 cfu/g), and yeast (0.33-1.53 log10 cfu/g) loads are below standard. The microbiological quality of the three types of "Soumbara" is unsatisfactory. Overall, "Soumbara" powder is the most contaminated, followed by granulated and paste "Soumbara." "Soumbara" must be added during culinary preparations in order to avoid possible public health problems.

Fungal Variation during Peanut Paste Storage.

Peanut paste produced in multipurpose mills is very often the site of choice for fungal contaminants that pose a major risk to consumers. The objective of this study is to evaluate the level of fungal contamination of peanut paste produced according to different moulding processes during storage. Thirty samples of peanut paste were produced from 60 kg of peanut pods according to three types of moulding (domestic moulding, artisanal moulding, and hygienic moulding) and then preserved for three months. These thirty samples were subjected to microbiological analysis using the conventional mould count method. The moisture content of the various peanut pastes was determined according to the AOAC method. Fungi were identified by using taxonomic schemes based on microscopic observation and culture appearance. Mould loads ranged from 0 to 6.4.102 cfu/g; 91 to 9.6.102 cfu/g; and 0 to 4.6.102 cfu/g, respectively, for domestic, artisanal, and hygienic mouldings during conservation. Moisture content increases during the conservation of peanut paste. It increases from 1.23 to 3.17% for domestic moulding, 1.30 to 3.20% for artisanal moulding, and 1.30 to 2.94% for hygienic moulding. Four fungal genera, namely, Aspergillus, Mucor, Absidia, and Penicillium and three species of Aspergillus including A. flavus, A. fumigatus and A. niger have been identified. The peanut paste produced from domestic and hygienic moulding is less contaminated during storage than that obtained in the artisanal way.

Influence of yeasts on bioactive compounds content of traditional sorghum beer (tchapalo) produced in Côte d'Ivoire.

Traditional sorghum beer is reputed for its therapeutic virtues in according the consumers. A number of biological active compounds like phenolic compounds (phenol, tannins, flavonoids, anthocyanins), diets fibers and compounds with clinically demonstrated antimalarial activity (quinine formate, quinine dihydrochloride, chloroquine) and antioxidant activity (2,2-diphenyl-1-picryl-hydrazyl and ferric reducing-antioxidant power methods) were evaluated in sorghum wort and beers fermented by wild yeasts and pure culture of Saccharomyces cerevisiae. The total phenol content in the samples ranged between 1254.69 ± 2.31 and 239.68 ± 11.92 µg/mL GAE. Antioxidant activity with 2,2-diphenyl-1-picryl-hydrazyl analysis method was high in sorghum wort with 73.33 ± 1.15% but with ferric reducing-antioxidant power analysis method, the antioxidant activity was high in beer from pure culture of Saccharomyces cerevisiae. No compounds with clinically demonstrated antimalarial activity were found in the samples. At bioactive compounds (phenolic compounds) content point view, statistical analysis showed similarity between the two beers.