PURPOSE: To carry out processing of a food freezable and preservable without impairing aroma and flavor by mixing a prescribed amount of starch, etc., in additive materials such as an ingredient added to cooked rice so as to dissolve the additive materials at the preset temperature, treating the resultant mixtures and sealing the treated mixture in a container.

CONSTITUTION: In additive materials such as an ingredient or soup added to cooked rice, are mixed 1-5% respective adequate amounts of starch, agar, a protein, etc., so as to dissolve the additive materials at the preset temperature. The resultant mixtures are subsequently treated. The cooked rice, ingredient, etc., are then suitably combined and sealed in a container to carry out processing of a freezable and preservable food.