Bioactive compounds and antioxidant activities of two industrial beers produced in Ivory Coast.

Beer is a world-famous beverage that is universally popular. This might be as an effect of its sensory, nutritional, and therapeutic qualities. To date, in Côte d'Ivoire, no study has been carried out focused on the eventual health benefits of industrial beer consumption. In this study, the bioactive compounds (total phenols, total tannins, total flavonoids, total anthocyanins) and corresponding antioxidant activities of two industrial beers from maize and rice from two different breweries were investigated. Results showed that for all phenolic compounds, contents were not statistically different (P > 0.05). However, antioxidant activities (antiradical activity and ferric reducing antioxydant power) were more important in industrial beer from rice (57.57 ± 0.62% and 109.46 ± 0.39 µg/mL ascorbic acid irrespectively) than industrial beer from maize (39.19 ± 1.02% and 103.51 ± 0.62 µg/mL ascorbic acid). Total phenols, total flavonoids, and total anthocyanins were mostly responsible for the antioxidant activities (antiradical activity and ferric reducing antioxydant power) of two beers, with correlation coefficients ranging from r = 0.614 to r = 1. Globally, the two industrial beers were similars but differents from local traditional sorghum beer. Occurrence of phenolic compounds in beers coupled with antioxidant activities shows that beer consumption could have health benefits to condition that beers have a low-alcohol content and light-to-moderate consumption. However, further investigations aims health benefis aspect are necessary.

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.

Evaluation of the contamination by bacteria of the Bacillus cereus group and the determination of some physico-chemical parameters of Attiéké garba sold in Daloa (Central West, Côte d'Ivoire).

In Côte d'Ivoire as elsewhere in Africa, attiéké plays an important role in feeding the population. The objective of the work is to conduct a study on the sanitary quality of the attiéké garba sold in Daloa. Fifty (50) samples of attiéké garba were collected by purchase from various high-traffic outlets in different districts of Daloa town. Samples are collected in the morning around 10 a.m. every 2 days at a rate of 10 per site. Microbiological analyzes and the determination of some physico-chemical parameters of attiéké garba were carried out. The bacterial load of Bacillus cereus present in the samples tested in the majority of districts is greater than or equal to 105 CFU/g of food. About 60% of the samples tested was contaminated with B. cereus spores against 72% contaminated with the vegetative form of B. cereus. However, physicochemical analyzes showed that attiéké garba was acidic and the humidity was between 37.36 ± 15.9 and 55.26 ± 20.5%. Attiéké garba could pose a danger to consumers.

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.

Organic production of vinegar from mango and papaya.

The study describes the transformation of mangoes of the local variety "Assabonou" and papaya solo No.8 into alcohol and then into vinegar through the process of directed fermentation. Indeed, mango and papaya juices extracted from ripe fruits contained in vials are first subjected to an alcoholic fermentation with Saccharomyces cerevisiae in anaerobic conditions and secondly to an acetic fermentation with strains of acetic acid bacteria cultivated from unpasteurized cider vinegar. To assess the quality of the vinegars produced, their profile and composition in organic acid and volatile compounds were compared to those of an unpasteurized cider vinegar from France and a vinegar produced in Côte d'Ivoire. The ethanol content for both juices is more or less high with 9.24 ± 0.04 g/L for mango and 12.68 ± 0.39 g/L for papaya. The concentration of acetic acid is the highest of the organic acids for the four vinegars ranging from 37.46 ± 4.6 g/L to 55.85 ± 9.94 g/L. The acetic acid contents of mango and papaya vinegars are close to that of unpasteurized cider vinegar from France but higher than that of vinegar produced in Côte d'Ivoire. Thus, this study allowed the production of "Assabonou" mango and papaya vinegars from two consecutive fermentations (alcoholic then acetic). This process is fast, less expensive and easily applicable. This application case could be an alternative for the processing of seasonal fruits to reduce postharvest losses.

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.

Bacillus subtilis Strains Isolated from Cocoa Trees (Theobroma cacao L.) Rhizosphere for their use as Potential Plant Growth Promoting Rhizobacteria in Côte d'Ivoire.

Plant growth promoting rhizobacteria (PGPR) are important for agriculture through their activity in stimulating and facilitating plant growth. The rhizobacteria were screened for molecular characterization and followed by their indole acetic acid (IAA) production, phosphate solubility, antibiosis activity. In this study, 162 soil samples were collected from the cocoa rhizosphere to isolate Bacillus subtilis strains using Mössel agar medium with an additional egg yolk and identified by sequencing the ytcP gene. The ability of each strain to form biofilms was obtained in a tube. Indole-3-acetic acid (IAA) production was estimated in Yeast Peptone Dextrose (YPB) broth. Phosphates were solubilized by each strain on Pikovskaya agar medium. The detection of lipopeptide genes using the molecular method has established the possession of isolates by antimicrobial genes. Fifty (50) B. subtilis strains were isolated and identified using the ytcP gene. Ninety percent (90%) of the strains were able to form a biofilm. All isolates produced an IAA. Forty (40 (80%)) of B. subtilis were solubilized phosphate with phosphate solubilizing index (PSI) of 0 to 97.33 ± 0.70%. Of all B. subtilis strains, 45 (90%) have the srfAA gene, 19 (38%) have the fenD gene and 12 (24%) have the ituC gene. B. subtilis strains from cocoa rhizosphere would be beneficial for agricultural production by their PGPR activities.

Assessment of safety risks associated with pork meat sold on the market in Abidjan city (Côte d'Ivoire) using surveys and microbial testing.

Pork meat is consumed in several forms base on the mode of cooking in Côte d'Ivoire. It is most often braised, grilled or cooked in soup. The aim of this study was to assess the importance of pork meat consumption in the diet of the Ivorian population. It also tried to assess the risks that consumers of this meat may incur in order to provide solutions through the implementation of good hygiene and manufacturing practices at the sites where this meat is sold. Thus, a consumption survey was conducted in the municipalities of Adjamé, Abobo and Yopougon. The enumeration of germs such as mesophilic aerobic germs, Staphylococcus aureus, Salmonella and coliforms was carried out too. It appeared that out of the three hundred (300) interviewees were all familiar with pork meat and 99% consumed it. The majority of consumers was masculine and 98% had Ivorian nationality. Among consumers, 52% had had at least one discomfort after eating pork. Symptoms of these ailments were vomiting, diarrhea and stomach aches. In addition, microbiological analyses of commercial forms of pork meat have revealed pathogenic germs such as Staphylococcusaureus, coliforms and mesophilic aerobic germs. Loads of mesophilic aerobic germs, Staphylococcus aureus and fecal coliforms ranged respectively from (1.2 ± 0.07)1010 to (1.3 ± 0.6)1011 CFU/g; from (2 ± 0.7)105 to (3.1 ± 0.7)106 CFU/g and from (1.1 ± 0.6)104 to (1.7 ± 0.91)105 CFU/g. All samples contained microbial loads above the European Community (EC) Standards No 2073/2005 for ready-to-eat pork meat. Pork meat then poses a health risk to consumers.

Characterization of Virulence Potential of Pseudomonas Aeruginosa Isolated from Bovine Meat, Fresh Fish, and Smoked Fish.

Pseudomonas aeruginosa owns a variability of virulence factors. These factors can increase bacterial pathogenicity and infection severity. Despite the importance of knowledge about them, these factors are not more characterized at level of strains derived from local food products. This study aimed to characterize the virulence potential of P. aeruginosa isolated from various animal products. Several structural and virulence genes of P. aeruginosa including lasB, exoS, algD, plcH, pilB, exoU, and nan1 were detected by polymerase chain reaction (PCR) on 204 strains of P. aeruginosa. They were isolated from bovine meat (122), fresh fish (49), and smoked fish (33). The 16S rRNA gene was detected on 91.1% of the presumptive strains as Pseudomonas. The rpoB gene showed that 99.5% of the strains were P. aeruginosa. The lasB gene (89.2%) was the most frequently detected (p < 0.05). In decreasing importance order, exoS (86.8%), algD (72.1%), plcH (72.1%), pilB (40.2%), and exoU (2.5%) were detected. The lasB gene was detected in all strains of P. aeruginosa serogroups O11 and O16. The prevalence of algD, exoS, and exoU genes in these strains varied from 51.2% to 87.4%. The simultaneous determination of serogroups and virulence factors is of interest for the efficacy of surveillance of infections associated with P. aeruginosa.

Calcium role in human carcinogenesis: a comprehensive analysis and critical review of literature.

The central role played by calcium ion in biological systems has generated an interest for its potential implication in human malignancies. Thus, lines of research, on possible association of calcium metabolism regulation with tumorigenesis, implying disruptions and/or alterations of known molecular pathways, have been extensively researched in the recent decades. This paper is a critical synthesis of these findings, based on a functional approach of the calcium signaling toolkit. It provides strong support that this ubiquitous divalent cation is involved in cancer initiation, promotion, and progression. Different pathways have been outlined, involving equally different molecular and cellular structures. However, if the association between calcium and cancer can be described as constant, it is not always linear. We have identified several influencing factors among which the most relevant are (i) the changes in local or tissular concentrations of free calcium and (ii) the histological and physiological types of tissue involved. Such versatility at the molecular level may probably account for the conflicting findings reported by the epidemiological literature on calcium dietary intake and the risk to develop certain cancers such as the prostatic or mammary neoplasms. However, it also fuels the hypothesis that behind each cancer, a specific calcium pathway can be evidenced. Identifying such molecular interactions is probably a promising approach for further understanding and treatment options for the disease.

Production of freeze-dried yeast culture for the brewing of traditional sorghum beer, tchapalo.

Freeze-drying is a well-known dehydration method widely used to preserve microorganisms. In order to produce freeze-dried yeast starter culture for the brewing purpose of African sorghum beer, we tested protective agents (sucrose, glucose, glycerol) in combination with support materials (millet, maize, sorghum, and cassava flours) at 1:1 ratio (v/v). The yeast strains Saccharomyces cerevisiae F 12-7 and Candida tropicalis C 0-7 previously isolated from sorghum beer were used in a mixed culture at a ratio of 2:1 (C. tropicalis/S. cerevisiae). After the freeze-drying, the residual water contents were between 0.78 -2.27%, 0.55 -4.09%, and 0.40-2.61%, respectively, with sucrose, glucose and glycerol. The dried yeasts viabilities were between 4.0% and 10.6%. Among the protective agents used, sucrose was found to be the best protectant giving cell viabilities of 8.4-10.6%. Considering the support materials, millet flour was the best support after drying. When the freeze-dried yeast powders were stored at 4°C and room temperature (25-28°C) for up to 3 months, the survival rates were the highest with cassava flour as the support material.

Fermentation profile of Saccharomyces cerevisiae and Candida tropicalis as starter cultures on barley malt medium.

Saccharomyces cerevisiae C8-5 and Candida tropicalis F0-5 isolated from traditional sorghum beer were tested for kinetic parameters on barley malt extract, YPD (863 medium) and for alcohol production. The results showed that C. tropicalis has the highest maximum growth rate and the lowest doubling time. Values were 0.22 and 0.32 h(-1) for maximum growth rate, 3 h 09 min and 2 h 09 min for doubling time respectively on barley malt extract and YPD. On contrary, glucose consumption was the fastest with S. cerevisiae (-0.36 and -0.722 g/l/h respectively on barley malt extract and YPD). When these two yeasts were used as starters in pure culture and co-culture at proportion of 1:1 and 2:1 (cell/cell) for barley malt extract fermentation, we noticed that maltose content increased first from 12.12 g/l to 13.62-16.46 g/l and then decreased. The highest increase was obtained with starter C. tropicalis + S. cerevisiae 2:1. On contrary, glucose content decreased throughout all the fermentation process. For all the starters used, the major part of the ethanol was produced at 16 h of fermentation. Values obtained in the final beers were 11.4, 11.6, 10.4 and 10.9 g/l for fermentation conducted with S. cerevisiae, C. tropicalis, C. tropicalis + S. cerevisiae 1:1 and C. tropicalis + S. cerevisiae 2:1. Cell viability measurement during the fermentation by using flow cytometry revealed that the lowest mean channel fluorescence for FL3 (yeast rate of death) was obtained with C. tropicalis + S. cerevisiae 2:1 after 48 h of fermentation.

The Use of MALDI-TOF Mass Spectrometry, Ribotyping and Phenotypic Tests to Identify Lactic Acid Bacteria from Fermented Cereal Foods in Abidjan (Côte d'Ivoire).

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) protein analysis, automated ribotyping, and phenotypic tests (e.g., cell morphology, gas production from glucose, growth and acid production on homofermemtative-heterofermentative differential (HHD) agar medium, sugar fermentation patterns) were used to identify 23 lactic acid bacteria (LAB) isolated from fermented cereal foods available in Abidjan, Côte d'Ivoire. Pediococcus acidilactici (56.5%), Lactobacillus fermentum (30.4%), L. salivarius (4.3%), P. pentosaceus (4.3%) and L. plantarum subsp. plantarum (4.3%) were the species and subspecies identified. Protein based identification was confirmed by automated ribotyping for selected isolates and was similar to that provided by the phenotypic characterization. MALDI-TOF MS protein analysis provided a high level of discrimination among the isolates and could be used for the rapid screening of LAB starter cultures.

Clostridium perfringens and Clostridium difficile in cooked beef sold in Côte d'Ivoire and their antimicrobial susceptibility.

The aim of this study was to evaluate the prevalence of Clostridium difficile and Clostridium perfringens in cooked beef sold in the streets in Côte d'Ivoire and their antimicrobial susceptibility. A total of 395 kidney and flesh samples of cooked beef were collected from vendors at Abidjan and subjected to C. difficile and C. perfringens isolation and identification by using biochemical tests, API 20A system and PCR detection. Subsequently, the antimicrobial susceptibility test was performed for confirmed isolates. Our results showed the prevalence of 12.4% for C. difficile (11.04% in kidney and 13.45% in flesh) and 5.06% for C. perfringens (2.32% in kidney and 7.17% in flesh). Metronidazole and vancomycin remained the most potent antimicrobial agents against C. difficile while metronidazole and penicillin G were the most potent agents against C. perfringens. The resistance rates to tetracycline, doxycycline, chloramphenicol and erythromycin against C. difficile and C. perfringens isolates ranged from 2.05% to 8.16% and from 20% to 50%, respectively. Among all antimicrobial agents tested against C. difficile, percentages of resistance to quinolones ciprofloxacin, norfloxacin and nalidixic acid as well as to gentamicin and cefotaxime were the highest. Eight resistant phenotypes were defined for C. difficile isolates and eleven resistant phenotypes for C. perfringens isolates. Clindamycin/gentamicin/cefotaxime/ciprofloxacin/norfloxacin/nalidixic acid resistance was the most common phenotype for C. difficile (55.10% of isolates) while norfloxacin/nalidixic acid resistance was the most common phenotype for C. perfringens (20% of isolates).

The Use of Lactic Acid Bacteria Starter Cultures during the Processing of Fermented Cereal-based Foods in West Africa: A Review.

Lactic acid bacteria (LAB) are the primary microorganisms used to ferment maize-, sorghum- or millet-based foods that are processed in West Africa. Fermentation contributes to desirable changes in taste, flavour, acidity, digestibility and texture in gruels (ogi, baca, dalaki), doughs (agidi, banku, komé) or steam-cooked granulated products (arraw, ciacry, dégué). Similar to other fermented cereal foods that are available in Africa, these products suffer from inconsistent quality. The use of LAB starter cultures during cereal dough fermentation is a subject of increasing interest in efforts to standardise this step and guaranty product uniformity. However, their use by small-scale processing units or small agro-food industrial enterprises is still limited. This review aims to illustrate and discuss major issues that influence the use of LAB starter cultures during the processing of fermented cereal foods in West Africa.

Identification of yeasts during alcoholic fermentation of tchapalo, a traditional sorghum beer from Côte d'Ivoire.

This study investigated the diversity and dynamics of yeasts involved in alcoholic fermentation of a traditional sorghum beer from Côte d'Ivoire, tchapalo. A total of 240 yeast strains were isolated from fermenting sorghum wort inoculated with dry yeast from two geographic regions of Côte d'Ivoire (Abidjan and Bondoukou). Initial molecular identification to the species level was carried out using RFLP of PCR-amplified internal transcribed spacers of rDNA (ITS1-5.8S-ITS2). Ten different profiles were obtained from the restriction of PCR products with the three endonucleases HaeIII, CfoI and HinfI. Sequence analysis of the D1/D2 domain of the 26S rDNA and the ACT1 gene allowed us to assign these groups to six different species: Saccharomyces cerevisiae-like, Candida tropicalis, Pichia kudriavzevii, Pichia kluyveri, Kodamaea ohmeri and Meyerozyma caribbica. The most frequent species associated with tchapalo fermentation was S. cerevisiae-like (87.36%), followed by C. tropicalis (5.45%) and M. caribbica (2.71%). S. cerevisiae-like strains were diploid heterozygotes and exhibited three to four nucleotides divergence from the type strain in the D1/D2 domain and several indels in the more discriminant sequence of the intron of the ACT1 gene. During the process, the yeast species isolated and their frequencies varied according to the geographic origin of the dry yeast. The occurrence of some species was sporadic and only two non-Saccharomyces species were found in the final product.

Les complications uro-génitales de la chirurgie pelvienne et du canal inguinal : au sujet de 15 observations

Objectif: La chirurgie pelvienne et du canal inguinal expose à des complications parmi lesquelles les lésions iatrogènes urogénitales. Le but de ce travail était de rapporter notre expérience de ces complications. Patients et méthodes: Il s'agit d'une étude retrospective des complications uro-génitales survenues au cours de cette chirurgie entre le 1er janvier 1997 le 31 décembre 2001. Elle comprend 15 patients (10 hommes et 5 femmes dont l'âge moyen est de 35,5 ans) opérés en programme opératoire réglé de hernie inguino-scrotale (n=4), de fibrome utérin (n=3) ou en urgence de hernie inguino-scrotale étranglée (n=4), de volvulus du côlon sigmoïde (n=1), de cancer du rectum en occlusion (n=1), de rupture utérine (n=1) et de pyoannexe gauche (n=1). Résultats: Les lésions étaient des sections ou plaies urétérales (n=7), des plaies ou em-brochages vésicales (n=6) et des lésions artérielles testiculaires (n=2). Six lésions ont été découvertes immédiatement tandis que neuf ont été méconnues et se sont manifestées par un syndrome péritonéal (n=7) et par une atrophie testiculaire (n=2). Le traitement réalisé était une cystorraphie sur sonde (n=7), une suture urétérale sur catheter (n=6), une réimplantation urétérale (n=1) et une orchidectomie (n=2). La morbidité pour les réinterventions était nulle. Un patient est décédé à J12 post-opératoire - il s'agit du patient opéré pour cancer du rectum en occlusion. Conclusion: La prévention des lésions urogénitales passe par l'application rigoureuse de techniques bien apprises par des chirurgiens expérimentés