PASTING PROPERTIES OF COWPEA FLOUR - EFFECTS OF SOAKING AND DECORTICATION METHOD

Pasting properties of flour prepared from 12 diverse cowpea varieties as affected by dry and wet decortication processes were determined usi ng a Brabender viscoamylograph. Dry decorticated flour (DDF) was prepa red hom seeds wetted, dried, and mechanically dehulled; wet decorticat ed flour (WDF) was prepared from seeds soaked, manually decorticated, dried, and milled to flour. No pasting peak was obtained during heatin g of flour slurry to 95 degrees C for both DDF and WDF for all cowpea varieties. WDF samples had higher paste viscosities than DDF samples. Presoaking of seeds (2, 4, 8, or 16 h) affected paste viscosities, esp ecially hot paste viscosity (HTPV), and particle size distribution. Ma ximum HTPV and highest quantities of medium-size particles (mesh 40-80 , 0.42-0.177 mm) were attained with flour prepared from seeds presoake d for 4 h. Presoaking for more than 4 h did not yield further increase in HTPV, Cowpea flour with at least 65% of medium-size particles exhi bited the best hydrothermal properties, leading to increased rate of m oisture absorption and higher HTPV during aqueous heating of slurry.