Physicochemical and functional characterisation of dioscorea bulbifera l. and coleus esculentus n. e. br. tubers in north-Cameroon

The study aimed to investigate on the physicochemical and functional properties of tubers (D. bulbifera and C. esculentus) “bugumdjigordi” purchased from the Garoua (Katasko market) and Maroua (Central market) markets. The physical characteristics (weight, diameters and length) of tubers were measured and the physicochemical properties (dry matter, protein, starch, sugar, minerals and polyphenols) as well as the functional properties (water absorption capacity, swelling rate, solubility) of flour from tubers were analysed. From the results, Physical parameters were generally affected by the site of collection except the mass which was not affected by the collection site and species. The starch and crude protein contents showed a significant difference (p<0.05) with respect to site of collection and D bulbifera had significantly (p<0.05) high total and free sugars contents. The highest (p<0.05) total ash, calcium and iron contents was obtained with C. esculentus. However, C. esculentus from Garoua showed the higher (p<0.05) phosphorus content. Polyphenols, phytates were unequally distributed according to species and site and, total oxalates considering to species. Flour from C. esculentus had better functional properties than that of D. bulbifera except the flour density which was similar (p˃0.05). Tubers from C. esculentus could be more appropriated for infants’ food preparation.