Control measures in Nigerian traditional food manufacture: some Useful properties of extruded millet-soybean for the ‘fura’

Abstract

‘Fura’ is a traditional thick dough ball snack produced principally from millet or sorghum which is
common in Northern Nigeria. It is consumed with ‘nono’ (local yoghurt produced from cow milk) or
mashed in water before consumption in the form of porridge. The effects of extrusion conditions feed
composition (ratio of soybean to millet), percentage moisture wet basis and screw speed (rpm) on the
water absorption index (WAI); water solubility index (WSI) and viscosity from millet/soybean flour
mixtures were studied using Response surface methodology (RSM) for ‘fura’ processing. Models were
developed and appropriate statistical analysis adopted to test the adequacy of the models. The models
showed R2
= 0.73, 0.76, 0.74 for WAI, WSI and viscosity, respectively, indicating that the model could be
used to navigate the design space. Because some of the stationary points were outside the range of the
experiment, graphical optimization was adopted to determine the optimum and predicted values. The
optimum levels and the corresponding predicted values were obtained. The optimal combination of feed
composition (17.7% soybean), feed moisture (27.3% wet basis) and screw speed (161 rpm) resulted in
optimal WAI of 4.6 gWater per gSample . The optimal combination of feed composition (14.77% soybean),
feed moisture (15.23%) and screw speed 220 rpm) resulted in optimal WSI of 6.15%. The optimal
combinations of feed composition (46.97%), feed moisture (29.34%) and screw speed (174.52rpm)
resulted in optimal viscosity of 4.58 Nsm-2
.