PURPOSE: To impart a color formation effect, having improved flavor and light resistance, and partially resembling D-xylose to a fish-paste product, by adding 2-keto-hexonic acid or a derivative thereof in a specific proportion thereto.

CONSTITUTION: 2-Keto-hexonic acid expressed by the formula (M is amino acid having added H, Na, K, NH4, 1/2Ca, 1/2Mg or hydrogen ion) or a derivative thereof in an amount of 1.0% or below is added to a fish-paste product. A pH adjustor, e.g. polymerized phosphate, elasticity enhancer, edible surfactant, e.g. lecithin, are used together if necessary.