Review on pounded yam extensibility texture of 138 genotypes analysed by Kieffer dough extensibility at CNRA, Côte d'Ivoire

The CNRA yam genetic resources collection contains a diversity of accessions consisting of traditional, introduced and hybrid varieties. This collection was subjected to characterization of the quality of pounded yam (foutou) by texture in order to identify varieties suitable for making pounded yam. The instrumental texture parameters measured are the extensogram peak force (N), extensibility (mm), and extension area (N.mm). The results show that the measured parameters are positively and strongly correlated. Among these parameters, the extension area (N.mm) best discriminates among the genotypes while the extensibility (mm) best discriminates between the two species (alata and rotundata). PCA coupled with ascending hierarchical classification (ACH) made it possible to screen the varieties into three classes taking into account their extensibility, that is to say their ability to make pounded yam that extends in texture. Class 1 consists of 10 varieties with high extensibility. The varieties in this class, all of them of D. rotundata species, are capable of making good pounded yam and can therefore be selected as priority genotypes. Class 2 includes 21 varieties with medium extensibility. The varieties in this class, which include both D. rotundata and D. alata varieties, can make pounded yam of medium quality. Class 3 includes few varieties of D. rotundata, and most of the D. alata varieties of have low extensibility and cannot produce good quality pounded yam (foutou).