The free use of rice in the phenylketonurics diet needs the reduction of phenylalanine (Phe) content from its proteins. This procedure involves protein extraction and hydrolysis followed by Phe removal. Enzymatic processes were then used for extracting and hydrolyzing rice proteins. In the former, a protease from Bacillus licheniformis was used while for the second case, six different enzymes were tested (pancreatin, papain, proteases from Aspergillus sojae, Bacillus stearothermophilus and two from Bacillus subtilis). Also, the activated carbon (AC) was employed as the adsorptive medium for removing Phe. The efficiency of Phe removal was evaluated by second derivative spectrophotometry. The hydrolysate prepared with papain showed the highest Phe removal (94.1%), using an E:S ratio of 4:100, a protein:AC ratio of 1:88 and three different meshes of AC simultaneously.