One of the interesting marine products to be explored is flying fish (Hirundichthys oxycephalus) roes. The flying fish roe is usually called tobiko. The aim of this study is to extract protein from tobiko filaments using an isoelectric point approach, analyze their chemical properties, and apply them to the nutrification of rice-corn milk. Extraction of tobiko filaments using an isoelectric point approach resulted in an optimal pH of 8.5 based on the protein content (73.52 ± 0.07 %). Extraction under alkaline conditions (pH 8.5) resulted in a protein concentrate yield of 9.04% and an insoluble portion of 69.79%. That protein concentrate showed 15 amino acid, leucin (5.86 ± 0.01%), lycin (3.69 ± 0.02%), valin (3.41 ± 0.02%), isoleucine (3.33 ± 0.01%), threonine (2.86 ± 0.01%), phenylalanine (2.30 ± 0.02%), histidine (1.38 ± 0.01%), and methionine (1.21 ± 0.01%), glutamate (7.08 ± 0.01%), arginine (6.11 ± 0.01%), alanine (3.82 ± 0.01%), aspartic acid (3.75 ± 0.01%), serine (3.05 ± 0.02%), glycine (1.84 ± 0.01%), and tyrosine (1.46 ± 0.01%). The addition of protein concentrate from tobiko filament showed an increase in protein content in rice-corn milk so the purpose of nutrification in this study was successful. The best formulation is in the composition of rice: corn: protein concentrate (15:5:3%) with details of moisture content 65.07 ± 0.02%, ash content 0.50 ± 0.01%, the lipid content 0.28 ± 0.02%, the protein content 21.18 ± 0.02 %, the carbohydrate content 12.95 ± 0.02%, with a total energy 278.13 ± 0.03 kcal.