Effect of baking and amino acid supplementation on the protein quality of arabic bread

Abstract The effect of supplementation of flour with lysine, lysine‐threonine, lysine‐methionine, and lysine‐threonine‐methionine on the protein quality of Arabic bread was studied. In addition the effect of baking on the protein quality of non‐supplemented and supplemented flour and bread was investigated. For the preparation of bread samples the dough was made in the laboratory and baked in a local bakery. Rats were used for evaluation of protein by protein efficiency ratio, weight gain and feed consumption. The results showed that the addition of 0.3 % L‐lysine to flour improved the protein quality of flour and bread to a significant degree. Supplementation of lysine‐fortified flour with 0.62% DL‐threonine caused further improvement in protein quality, whereas methionine had no effect. Baking did not change the protein quality of lysine or lysine‐threonine supplemented bread.