Quality Characteristics of Processed Flours from Trifoliate Yam (Dioscorea dumetorum) as Influenced by Steeping and Boiling in Varying Concentration of Trona Solution over Time
The use of additives (trona solutions) in pretreatment of stored trifoliate yam in order to reduce cooking time and evaluation of quality characteristic of the resultant flours were studies. Selected tubers of trifoliate yam were cleaned and cut into chunks of 5 cm each. The cut portions were steeped in different concentrations of trona at loading rate of 1:2 (m/v) for 24 h. After steeping some portions were sliced to 5.0 mm thickness and sun-dried (3 days), milled and sieved with 1.0 mm mesh sieve. The remaining portions were boiled in different media for 120 min, dried, milled into flour. The flour samples were analyzed using standard methods for the proximate and functional properties. Steeping in varying concentration of trona gave significant decrease (p<0.05) in protein, gelatinization and boiling temperatures but increased the moisture value of the flour as the trona concentration increased. Boiling in different media after steeping in trona solution gave protein values: 6.62 for SSL; 7.20 for FPS and 7.12 for FWT; these did not differ at p>0.05. Trona solution was effective in reducing boiling temperature and modified the proximate and functional properties of trifoliate yam flours.