Bøger af Antoni Randrianantenaina

The aim of this study was to determine the physical, physico-chemical and nutritional characteristics and cyanogenic potential of the flours of three of the most widely grown cassava cultivars in the DIANA Region. Materials and methods were used to achieve this objective. The results obtained showed that the flours of these three cassava cultivars have water contents of 10.69% (Menarevaka), 11.38% (Mena) and 11.53% (Fotsy). These flours have pH values of 6.03 (Menarevaka), 5.74 (Mena) and 6.04 (Fotsy). The crude ash content of these flours (based on dry matter) is 1.75% (Menarevaka), 2.29% (Mena) and 2.57% (Fotsy). Their protein and fat contents are very low. The starch content (based on dry matter) is 73.56% (Menarevaka), 81.75% (Mena) and 82.97% (Fotsy). Their amylose content (dry matter basis) is 11.30% (Menarevaka), 11.22% (Mena) and 12.41% (Fotsy). Their cyanogenic potentials (in ppm HCN) are 3.40 (Menarevaka), 4.51 (Mena) and 2.44 (Fotsy). Although very low in protein and fat, these flours are rich in carbohydrates and non-toxic.

The physical and sensory characteristics of breads containing flour from the Malagasy cassava cultivar Menarevaka were determined. Composite loaves of 0/100, 5/95, 10/90, 15/85, 20/80, 25/75, 30/70, 35/65, 40/60, 45/55 and 50/50% cassava-wheat flour were produced using bread-making processes. Appropriate methods were used to determine the physical and sensory characteristics of the breads produced. The results obtained showed that the mass losses of the breads varied between 9.38% and 12.79%. Loaf heights ranged from 4.5 cm to 7.5 cm. Their volumes ranged from 189.35 cm3 to 340.76 cm3. Their specific volumes range from 1.23 cm3/g to 2.42 cm3/g. Good-quality loaves similar to control loaves can be obtained up to a 25% incorporation rate of cassava flour. Above this level, bread quality deteriorates. However, the addition of Magimix, at a rate of 0.5 g per 100 g of flour, improves the quality of composite loaves. Flour from this cassava cultivar can be used in bread-making to reduce the amount of wheat flour imported by the Malagasy.

This study was carried out with the aim of determining the rheological properties of the flours of three Malagasy cassava cultivars most widely consumed by the population in the DIANA Region, Madagascar. Seven rheological parameters were determined. The results obtained showed that the gelatinisation start temperature (in °C), peak viscosity (in cP), minimum viscosity (in cP), maximum viscosity drop (in cP), final viscosity (in cP), retrogradation (in cP) and peak viscosity time (in min) were respectively: for Menarevaka cassava flour : 70.95 ± 0.05; 5227.00 ± 30.05; 2817.33 ± 13.28; 2409.67 ± 17.24; 3601.67 ± 42.19; 784.33 ± 28.94 and 4.51 ± 0.03 , for Mena cassava flour: 71.52 ± 0.53; 5882.33 ± 50.14; 2994.00 ± 23.64; 2888.33 ± 26.50; 3860.00 ± 41.58; 866 ± 19.08 and 4.51 ± 0.03, for Fotsy cassava flour: 70,97 ± 0,08 ; 5679,00 ± 141,49 ; 2955,67 ± 8,39 ; 2723,33 ± 143,44 ; 3870,33 ± 17,56 ; 914,67 ± 25,11 ; 4,40 ± 0,07. These results showed that the flours of three Malagasy cassava cultivars analysed have significant rheological properties.