Functional quality evaluation of flakes produced from sorghum and African yam bean flour

Abstract

Background: Sorghum and African yam bean (AYB) are important crops in Nigeria and when produced into flour separately or composite are important sources of healthy foods.

Objective: This study evaluated the functional quality of flakes made from sorghum and AYB composite flours.

Methods: Five composites were produced by mixing the flours in different proportions. Flakes were produced by extrusion at temperature of 80ºC and 100 rev/minute and dried in oven at 50ºC. The flours were subjected to functional and pasting analyses while the flakes were subjected to proximate, mineral and colour analysis using laboratory standard methods. Data obtained were subjected to analysis of variance and means were separated using Duncan’s Multiple Range Test at 95% confidence level.

Results: The bulk density and water absorption capacity increased with the addition of AYB while swelling power decreased in the flours. Proximate composition of the flakes increased as the addition of AYB increased. Trough and breakdown viscosity of the composite flour were significantly (p < 0.05) different. The flakes contained 2.10-2.42% ash, 5.11-14.00% protein, 2.59-2.98% fat, 1.89-2.19% crude fibre and carbohydrate 75.17-85.10%. The mineral contents for the flakes ranged from 18.65-21.34mg/100g for calcium, iron 10.58- 12.03mg/100g and potassium 355.47-398.42 mg/100g.

Conclusion: The sorghum and AYB composite flours had the potentials of substituting wheat flour for producing acceptable quality flakes.

Keywords: Sorghum, African yam bean, composite flour, flakes