Abstract

     Flours processed from eight cassava roots were selected from recently developed Cassava Mosaic Disease resistant varieties (92b/00061, 95/0289, 92/0057, 96/1632, 98/0505, 97/2205, TME419 and 92/0326). They were processed into noodles adapting a locally fabricated cold extruder as a single –screw extruder. The extruded cassava noodles were cooked and subjected to expansion ratio analysis and clustering sensory studies.  There were no significant (P ≥ 0.05) differences in the expansion ratios of noodles from different varieties. However, there were significant (P ≤ 0.05) changes in expansion ratio due to processing. Those dried were about 1.98 times the diameter of the raw, while those cooked were up to 3 times the diameter of the raw. Principal component and cluster analyses of the parameters were adopted using the correlation matrix. Noodles made from 95/0289 CMD variety had the least acceptable sensory properties while those made from 98/0505 were most generally acceptable. No significant (P ≥ 0.05) differences were noticed in taste, colour and general acceptability of all the samples. The sensory evaluation of noodles made from the 8 cassava varieties produced 2 principal components which accounted for 85.80% while the functional properties explained 81.30% of the variations. The key sensory properties that made the contributions, selected from the PC analysis based on their loadings (P ≥ 0.5), were colour, taste, texture and general acceptability. The result showed that cassava flour could serve as a good substitute to wheat flour in noodle production and utilization.

Key words: Cassava mosaic disease, cassava flour, noodles, extrusion, single-screw extruder, sensory evaluation, expansion ratio, principal components, cluster analysis, dendrogram, hierarchical tree, Eigenanalysis, correlation matrix.