Effects of Cultivar and Drying Method on Color, Pasting and Sensory Attributes of Instant Yam (Dioscorea rotundata) Flours

Effect of cultivar (Efuru and Abuja) and drying method (cabinet and foam mat) on color, pasting, and sensory properties of instant pounded yam flours was investigated. Color (L*, a*, b*) values of fresh and dried flour samples were measured, and deltachroma (a dagger C), color difference (a dagger E), and hue angle were calculated. Pasting properties of flour and sensory attributes of fresh and reconstituted flour were determined. Foam density of yam pastes decreased from 0.97 g/cm(3) to between 0.362-0.538 and 0.308-507 g/cm(3) for cultivars Abuja and Efuru, respectively. Foam-mat dried flour showed higher L*, Delta C, Delta E, and hue angle but lower a* and b* values. Peak viscosities of cabinet and foam-mat dried Abuja and Efuru were 217, 304, 377.42, and 316.50 RVU, respectively. Sensory attributes of reconstituted foam-mat dried Abuja and fresh pounded yam were not significantly different (p > 0.05). However, fresh pounded yam (8.5-8.9) and reconstituted foam-mat dried flour (7.4-8.5) samples were significantly different (p > 0.05) from the cabinet-dried (6.9-7.9) and commercial samples (7.2-7.8).