Aiming the introduction of rice in the phenylketonurics diet, the protein extraction and phenylalanine (Phe) removal processes were studied. For protein extraction, an enzymatic method was used and for Phe removal, a papain and an Activated Carbon (AC) were used. The influence of protein:AC ratio, type and way of using AC was tested. The efficiency of Phe removal was evaluated by second derivative spectrophotometry. The results showed that the condition which gave the highest protein extraction yield (63.4%) was that using a sample concentration of 1:10 (w/v) at a temperature of 50°C, as well as an enzyme:substrate ratio of 10:100 at a reaction time of 5 h. Activated carbon was efficient for removing Phe, leading to values above 70% for most of the samples and the best result (94.1% of Phe removal) was found for a protein:AC ratio of 1:88, using simultaneously three types of AC (20x50, 12x25, 6x12 mesh), which led to a final Phe content of 82.5 mg kg^-1 of hydrolysate.