PURPOSE: To obtain a speck inhibitor widely usable for dough comprising wheat flour as a raw material, suppressing occurrence of speck, change in color and fading of dough without coloring dough composed of wheat flour as a raw material requiring whiteness, such as wheat vermicelli, pastry shell of a fried dumpling stuffed with minced pork and dough for bread.

CONSTITUTION: This quality improver for wheat flour and wheat flour product comprises a thiazole analog compound as an active ingredient. The thiazole analog compound is a compound having a thiazolium structure and is preferably a thiamine. The method for improving wheat flour and wheat flour product comprises blending wheat flour with 0.01-1wt.% of the quality improver for wheat flour and wheat flour product calculated as thiamine hydrochloride.