Theses et Memoires de l'universite d'Antananarivo

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In order to identify a process of cassava roots into the most panifiable flour and having the lowest cyanogenic potential, the influence of three technological factors on the physico-chemical characterstics and breadmaking value of cassava flour was studied. The three factors considered are the peeling, the reduction and the fermentation of roots. A 2 x 4 x 3 factorial experiment in randomized complete block design with 6 replications was selected. The roots of International Institute of Tropical Agriculture improved cassava clone, cultivated without fertiliser on a field in Ajibade (Ibadan, Nigeria) were used. The results obtained showed that fermentation is the most influential factor. The most panifiable flour and having the lowest cyanogenic potential was obtained from peeled roots, reduced in shreds, fermented in water for 72 h and sun-dried for 4 days after a night of dewatering. This process was applied to the roots of three malagasy cassava varieties (Madarasy, Rangotrakoho and Mambole) cultivated without fertiliser. Madarasy and Rangotrakoho are cultivated on a field in Anjomakely (Antananarivo) and Mambole in Andranofasika (Mahajanga). The breadmaking properties of composite flours at different pourcentages of the flour of these three cassava varieties were studied. It has been demonstrated that the flours of Madarasy and Mambole are the most panifiable. Good quality breads comparable to bread entirely made from wheat flour could be produced with a level of incorporation of these cassava flours up to 30 %. Addition of 0,5 % Magimix to the composite flours improves the quality of composite breads and delays the breads firmness. In this case, 40 % of each of these cassava flours could be incorporated in wheat flour to produce acceptable breads. Therefore, the perspective of the partial substitution of wheat flour with flour from peeled cassava roots, reduced in shreds and fermented in water seems interesting.

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