Studies on Changes in Color and Flavor of Sake Caused by Exposure to Light and Storage (XV) Effect of Metals on Changes in Color by Storage

Abstract

The effect of metals on changes in the color of sake during storage was studied.
The coloring reaction of sake during storage was decreased by treatment with Dowex A-1, in which Mn²⁺, Cu²⁺ and Zn²⁺ were adsorbed effectively.
Elute (M fraction) from Dowex A-1 with 1 N HCl showed the same effect as the ashed M fraction on the coloring reaction of sake treated with Dowex A-1, and so metallic ions in the elute accounted for the effect of the M fraction.
It was found that the coloring reaction of sake was stimulated by Mn²⁺, Cu²⁺ and Fe³⁺ in the M fraction.
The activities adsorbing matallic ions with various resins and an active carbon were investigated and Dowex A-1 was the most effective among them.