A Note on Supplementation of Feterita Sorghum Flour with White Bean Flour and its Effect on Sorghum Protein Quality

Abstract

Changes in Feterita sorghum amino acids profile, protein score and net
protein value as well as the ratios of leucine to isoleucine, leucine to lysine and arginine
to lysine due to white bean supplementation were studied. The results confirmed that the
protein quality of Feterita sorghum is very low as reflected by its low protein score
(35%), low net protein value (5.7%) and imbalanced ratios of its amino acids.
Supplementation of Feterita sorghum flour with white bean flour had beneficial effects
on the quality and quantity of Feterita sorghum protein. Addition of 30% decorticated
white bean flour to Feterita sorghum flour (70% extraction rate) overcame lysine
deficiency in Feterita sorghum protein, whereas the other essential amino acids were
more abundant than is needed for the physiological needs of children as envisaged by the
FAO/WHO/UNU. Also, the protein score and the net protein value were increased from
35% and 5.7% in Feterita sorghum flour to 99% and 19 %, respectively. Moreover, the
ratios of leucine to isoleucine, leucine to lysine and arginine to lysine were favourably
changed to the safety limits predicted by the FAO for preventing the pellagragenic
effect of sorghum proteins.