For the purpose of obtaining two protein hydrolysates from peptiona (Arca zebra), to be used as nutritional ingredients in accepted food items destined for human consumption, the enzymes bromelain and papain were studied. The effect of adding each of these proteases, on the rate of hydrolysis and conversion extent of insoluble pepitona protein to soluble nitrogen, were examined. Distilled water was added to the raw material to give a 2:1 ratio of solvent to pepitona, and mixed to produce a slurry at a pH of 6.4-6.5, with a total nitrogen value of 0.97% (w/v). Optimum conditions of hydrolysis were found to be two hours at 40 degrees C for both enzymes, at a pH of 7 and 0.3 g enzyme/100 g pepitona for papain, and a 0.2 g enzyme/100 g pepitona at pH 6.4 normally found in pepitona in the case of bromelain.