To effectively utilize the palatability components included in the soaking liquid of a seasoned cod roe after maturing the seasoned cod roe, as a food additive, and solve the problem in the disposal of the soaking liquid.

A solid capable of being utilized as the food additive is obtained by evaporating and drying the soaking liquid of the seasoned cod roe at a low temperature without decomposing the palatability components comprising proteins, various kinds of amino acids, and the like, included in the soaking liquid. Various kinds of processed foods having the flavor same as that of the seasoned cod roe are produced by adding an adequate amount of the obtained palatability components to the processed food. As a result, various kinds of problems in the disposal of the soaking liquid of the seasoned cod roe are solved at all.