Chemical composition and nutritional quality of sorghum flour and bread

Two Saudi Arabian sorghum cultivars, white and reddish white, were investigated for their chemical and nutritional quality. The two cultivars were similar in proximate composition (white 15.3% protein, reddish-white 15.9% protein), mineral profile, fatty acid composition, vitamin content (except vitamin-B₁₂ was higher in reddish-white), in vitro protein digestibility (IVPD) and calculated protein efficiency ratio (C-PER). White sorghum had lower tannins (0.09% catechin equivalent) compared to the reddish-white (0.27% catechin equivalent). Lysine was the first limiting amino acid in both with chemical scores of 45 and 47 for the proteins of white and reddish-white cultivars, respectively. Baking had no effect on proximate, fatty acid and amino acid composition. However, it increased the Na and Ca contents but decreased the K, P, and pantothenic acid contents. Tannins were not detected in the breads. Breads fermented for 18 h had higher vitamin-B₁₂ and pantothenic acid levels but lower P content than unfermented breads. A slight increase in tyrosine, lysine, methionine contents as well as C-PER was also observed in fermented bread.