Effect of Malting Conditions on Proximate and Functional Properties of Malted Sorghum Flour at Optimized Condition Using Response Surface Methodology

Abstract

The demand for indigenous flour has increased over the years as a result of its industrial application. The study observed the effect of  malting on the proximate and functional properties of malted sorghum flour. Sorghum grains (white and red varieties) were germinated,  kilned and milled into flour. Response surface methodology (RSM) using Box-Behnken design was employed to optimize the effect of  germination period (GP), kilning temperature (KT), and kilning time (Kt). The proximate and functional properties of the flour were  determined using standard laboratory procedures. Data obtained were subjected to analysis of variance (ANOVA) while response surface  plots and regression analysis were done using design expert version 7. Moisture, crude protein, crude fat, crude fibre, bulk density and  swelling capacity ranged from 5.92 to 7.31%, 9.01-10.39%, 3.59-6.75%, 1.11-1.39%, 0.52-0.68g/ml, 1.15- 1.38g/g for white sorghum and  6.00-8.88%, 8.25-10.02%, 3.61-6.48%, 2.26-2.83%, 0.64-0.68 g/ml and 1.26-1.42 g/g red sorghum, respectively. Moisture and oil absorption  capacity were minimized while crude protein, crude fibre was maximized, the optimum malting condition for malted sorghum flour have  a germination period of 2.64 days, kilning temperature of 46°C and kilning time of 28 hours with desirability of 0.86 and germination  period of 2.92 days, kilning temperature of 52°C and kilning time of 32 hours with desirability of 0.82 for white and red varieties,     respectively