Comparative Evaluation of Physico-chemical Characteristics of Flours from Steeped Tubers of White Yam (Dioscorea rotundata Poir), Water Yam (Dioscorea alata L.) and Yellow Yam (Dioscorea cayenensis Lam)

The study examined Yam Tuber Species (YTS), Tuber Steeping Duration (TSD) and Flour Particle Size (FPS) as factors of flour. Data were collected using white yam, water yam and yellow yam steeped in water (30 ± 2 °C, pH 6.78) and withdrawn, and the flour classified, and analyzed for each parameter. Results obtained showed that all the test parameters, Water Retention Capacity (WRC), Swelling Index (SI), Solubility (TSS) and Iodine Affinity of Starch (IAS) correlated very much better and significantly (Pr< 0.10) with FPS than with TSD. Inverse relationships were observed with all the parameters. Analysis of variance (ANOVA) results indicated that no significance existed in the main factors for YTS (WRC and TSS). Otherwise, the study variables were found to be critical determinants for the magnitude and extent of the physicochemical properties of steeped yam flour pastes. The study also observed that white yam, steeped for up to 4 days at tropical ambient temperatures, and the resultant flour classified / pulverized into ≤ 125 m FPS will yield the optimum physicochemical features in the paste.