Comparative evaluation of the physicochemical and pasting properties of flour from three varieties of Brachystegia spp.

摘要

The chemical compositions, functional and pasting properties of flour from three varieties of Brachystegia spp. (Brachystegia eurycoma, Brachystegia nigerica and Brachystegia kennedy) were studied. Results show that the chemical compositions of flour samples ranged from12.31 to 12.67% (protein), 1.66 to 1.72% (crude fiber), 2.06 to 2.39% (ash), 7.18 to 8.45% (fat), 3.85 to 4.75% (sugar) and 58.45 to 59.62% (starch). Functional properties such as water absorption capacity, oil absorption capacity, swelling power, solubility index, pH and amylose content were in the ranges of 80.14 to 80.77, 84.21 to 84.52, 15.64 to 15.78, 15.44 to 15.98, 5.48 to 6.74 and 20.42 to 20.69%, respectively. In addition, pasting properties values were 85.58 to 89.05°C (peak temperature), 128.54 to 133.45 (peak viscosity), 23.75 to 26.53 (trough viscosity), 419.6 to 449.5 (final viscosity) 53.5 to 59.0 (break down viscosity) and 402.6 to 413.4 Relative value units (RVU) (setback viscosity). No significant difference (p > 0.05) was observed in the functional properties of the flours. The pasting profile showed that peak and hot paste viscosities are the key pasting parameters in characterizing flours from the three Brachystegia varieties. The variation in peak viscosity of the Brachystegia flours might be due to varietals and geographical influence. The study shows that B. eurycoma flour had the best functional and pasting properties results that could be exploited in food formulations such as soup, and sauces.Key word: Brachystegia flour, variety, chemical composition, functional, pasting properties.