Traditional retting of cassava roots in the ponds or the rivers

The traditional retting of cassava roots occurs in ponds or in backwaters. The medium pH is slightly acidic (pH 5.54) and the pressure of dissolved oxygen is very low (pO2 1.96). The fermentation of cassava roots lasts for three days in the rainy season (October to April) with an average temperature of 26 °C, but it is longer, 5-6 days, in the dry season (May to September) with an average temperature of 23 °C. The fermentation with peeled roots is preferred because it favours the rapid softening of cassava roots and it allows to shorten at least one day the fermentation duration. In addition, the peeled roots after retting contain less tannin than the unpeeled roots and allow to obtain the alimentary products, fufu and kwanga which have a higher whiteness. The bitter variety of cassava roots is more used in fermentation than the sweet variety. Retted cassava dough is well preserved one to two months in account of anti-microbial compounds produced by lactic acid bacteria. The variability of characteristics of the products obtained from retted cassava roots is the reflection of several factors, including the cassava variety, the environmental conditions and the retting method

Etude microbiologique des feuilles fermentées de manioc: "Ntoba Mbodi"

Microbiological Study of "Ntoba-Mbodi", Fermented Cassava Leaves. Some families and small processing units proceed by way of fermentation of the cassava leaves to make "ntoba mbodi", a dish with a particular taste and flavor. The fermentation process lastes 4 days and after that the product undergoes significant alteration. During fermentation, about 70% of the cyanogenic glucosides are eliminated compared to 82 to 94% by blanching, vapor cooking or sun drying. Thus fermentation can be considered as good in eliminating cyanide as these other methods. Contrary to other plant material whose fermentation leads to an increase in acidity, fermentation of cassava leaves leads to alkalinization, with the pH rising from 6.2 to 8.9. Microbiological analyses of the fermented cassava leaves reveal the unusual presence of Micrococcus varians, Bacillus macerans, Bacillus subtilis, Staphylococcus sciuri and Staphylococcus xylosus among the other usual microorganisms; however yeasts and Leuconostoc strains are not present. Among this micro-organisms, Bacillus macerans, Bacillus subtilis, Bacillus cereus, Staphylococcus xylosus and Erwinia spp. play an important role in with their polysaccharolytic enzymes

Variabilité et amélioration de la technologie traditionnelle de production de la pâte fermentée de maïs au Congo

Variability and Improvement of Maize Fermented Dough Traditional Technology Production in Congo. The poto-poto production proceeding is characterized by the large variability during some production stages, particulary in washing and conservation operations. The washing operation before and after steeping seems to be very important because it influences considerably the sensorial (colour, odour) and hygienic qualities of final product. For improving nutritional qualities, germinated seeds utilization has been studied. With respect to biochemistry characteristics, poto-poto made with germinated seeds offers a diminution of lactic acid concentration and an increase of acetic concentration. By contrary, for poto-poto produced from ungerminated seeds, lactic acid concentration increases and that of acetic acid decreases. The two products are acid (pH 3,8 and pH 3,53) because of lactic and acetic presence. The sensorial test makes evident the sensorial differences existing in two types of products. The are two different products with respect to colour, taste, odour and texture. Poto-poto produced with maize germinated seeds is preferred (100% among tasters). It is slightly more sweet (100% among tasters) and more sour (40% among tasters) than poto-poto produced from ungerminated seeds. The poto-poto solar drying proceeding used allows a better conservation of poto-poto

Volatile compounds produced in two traditional fermented foods of the Congo: Nsamba (palm wine) and bikedi (retted cassava dough)

The "nsamba" (palm wine) and "bikedi" (retted cassava dough) are respectively produced by fermentation from the sap of the oil palm (Elaeis guineensis Jack) and lactic acid fermentation from cassava root (Manihot cassava Crantz). The study is focused on the determination of volatile compounds present in these two traditional fermented foods of Congo at the end of fermentation. The characterization of these volatile compounds at the end of fermentation for “nsamba" and "bikedi" revealed as the main compounds esters, terpenes, fatty acids and long chain alcohols. Indeed, it was noted: for "nsamba" 86% esters (ethyl caprylate, ethyl decenoate, N-ethyl decanoic, ethyl laurate) and decanoic acid; for "bikedi" 43% terpenes and 37% alcohols: estragol, limonene, linalol, myrcene and menthol.Keywords: Palm wine, dough, cassava, aroma, fermentation.African Journal of Biotechnology, Vol 13(42) 4119-412

Study of characteristic parameters of traditional process in the production of “Boganda”, a brandy of Congo

“Boganda” is an appreciated traditional distilled alcoholic beverage in Congo. It brings an interesting income to producers though its quality is extremely variable from a workshop to another. The production is based on three stages: malting of corn, fermentation and distillation. The corn used initially undergoes, during 5 days, an uncontrolled germination in medium quickly becoming anaerobic, with an increase in temperature up to about 49 ± 3 °C; that causes death of majority of corn germs and formation of various flavours. The obtained fermented malt is distilled without column. The distillate is collected empirically in fractions of volume according to the alcoholic amount corresponding to little distinct stages of temperature up to 98 °C. The final distilled alcoholic beverage has an alcoholic degree of approximately 24.2 ± 3 °GL, the volume of collected distillate being extremely variable. The study of physicochemical characteristics reveals a very great dispersion of parameters of manufacturing process and quality of product. Keywords: Brandy, ethanol, optimization, “Boganda”. Int. J. Biol. Chem. Sci. Vol. 2 (3) 2008: pp. 258-27

Caractéristiques socio-démographiques dans la filière pâte rouie de manioc au Congo-Brazzaville

Socio-Demographic Characteristics in Die Cassava Paste steeped in Congo-Brazzaville. Cassava roots constitute a basic food in Congo. Its consumption in the form of foufou or chikwangue requires the transformation of the roots to steeped paste. Social dynamics related to the activity of production and marketing of the steeped paste, after investigation into 119 producers showed two markets in Brazzaville draining more than 40 % of the producers and retailers, one market in Pointe - Noire with 60 % of the producers and retailers, and the railroad importance for supplying these markets. Important activities are localised in rural zone more particularly in Mindouli and in Bouenza localities. Formerly forsaken with the women, the die of the steeped paste is more and more occupied by the men especially in Pointe - Noire, particularly in the marketing part considered to be less painful and more profitable. Production and marketing activities are carried out by the young people. Illiterates producers proportion is weak in Brazzaville, but stronger in Pointe - Noire. This study does not establish any bond associating the sex, the age, the instruction and the matrimonial statute in this activity

Evaluation of the traditional technology of production of lungwila, a wine of sugarcane of Congo

The aim of study was to evaluate the used technology in the production process of lungwila, a traditional drink of soils of sugarcane in the Basin of Congo. This beverage provided an interesting income for the producers although the quality varied from a workshop to another. The leaven used for the fermentation of lungwila wine was active and inoculated when the maximum of yeast cell concentration was reached (between 3.5x108 and 6x108 CFU of yeast/ml) from a propagation process carried out by adding up gradually of the increasing volume with fresh juice of sugarcane. During the fermentation, the consumption of sugars was limited to an average of 5.3°Brix marking the end of the process in 72-92 hours. At the end of the fermentation, the supernatant wine was crudely stripped of its amorphous particles by a natural decanting process and was subsequently drawed. The starter which results was regularly kept up every three to four cycles of fermentation by eliminating the superficial muddy phase and feeding, with fresh ingredients additives: it could serve on several other cycles of  fermentation for about a year. Analysis of physico-chemical parameters of finished product revealed that lungwila is an alcoholic beverage  (10.5±1.397% ethanol) having a sweet taste (6.29±2.40 °Brix) and sour (pH=3.22±0.173).Keywords: Lungwila, wine of soils, sugarcane, corn, fermentation on leaven