ABSTRACTThe solubilization of proteins in corn and sorghum, using sodium lauryl sulfate (NaLS) in a basic medium, was used for tryptophan determination. The experimental design evaluated different levels of sodium lauryl sulfate and sodium hydroxide, at various temperatures and times. Prior to treatment, the samples were dried, ground and defatted. These were hydrolyzed and tryptophan was quantified spectrophotometrically (λmax= 565 nm). Casein was used as control and DL‐tryptophan was used for generating the standard curve according to Beer's Law. From the results obtained, it was possible to conclude that sodium lauryl sulfate was very effective in solubilizing corn and sorghum protein for subsequent tryptophan determinati