Functional and Pasting Properties of Composite Flours from Triticum durum, Digitaria exilis, Vigna unguiculata and Moringa oleifera Powder

Abstract

The objective of this study was to determine the functional and pasting properties of composite flours from Triticum durum (wheat), Digitaria exilis (acha), Vigna unguiculata (cowpea) flours and Moringa oleifera leaf powder. The flour samples were mixed in a four by four factorial, in complete randomized design (CRD) to formulate the composite blends at four different levels (25, 50, 75 and 100) which gave 16 samples. The statistical analysis of data collected was used to select five (5) generally accepted composite flour samples (wheat, acha, cowpea and moringa oleifera leaf powder flours) with ratio of 100:0:0:0, 75:25:0:0, 0:50:50:0, 50:23:25:2 and 75:25:0:0, respectively. The flour samples were analyzed for functional and pasting properties using standard methods. Results of the functional properties showed that water absorption capacity of the composite flour blend ranged from 0.87-1.11g/g, bulk density 0.39-0.42 g/ml, least gelation concentration 2.00-4.00%, solubility 19.46-25.35%, wettability 2.57-4.02min, oil absorption 1.61-1.79g/g and least gelation temperature 62.00-68.50oC. The functionality of the composite flours such as water and oil absorption capacities, least gelation concentration and bulk density were improved when cowpea was incoporated into the blends than for moringa oleifera leaf powder and acha flour. On the other hand, wettability and solubility of the flour blends were improved when acha was incorporated into the blend. Results of pasting properties showed that peak viscosity ranged from 73.04-385.79RVU, trough viscosity 57.96-341.42RVU, break down viscosity 15.08-44.38RVU, final viscosity 109.54-581.58RVU, set back viscosity 51.58-240.17RVU, pasting time 5.70-6.40min and pasting temperature 50.08oC-50.35oC. These properties were shown to be higher when cowpea was incorporated into the flour blends than for moringa oleifera leaf powder and acha flour. However, pasting properties of the composite flour blends were higher than 100% wheat flour. This result therefore showed that composite flour from wheat, acha, cowpea and Moringa oleifera leaf powder has improved functionality and high pasting properties than the individual wheat flour and will serve as a useful ingredient in food formulations such as in dough, soups and baked products.