The use of standard electrode potentials to predict the taste of solid metals

Not all metals taste equally metallic when placed in the mouth. While much work has been done to examine the metallic taste sensations arising from metal ions in solutions, there is comparatively less known about the taste of solid metals. In this study seven metals in the form of spoons were used to compare the perception of taste arising from solid utensils placed inside the mouth. Thirty-two participants tasted seven spoons of identical dimensions plated with each of the following metals: gold, silver, zinc, copper, tin, chrome and stainless steel. More negative standard electrode potentials were found to be good predictors of solid metals that had tastes scoring highest for the taste descriptors strong, bitter and metallic. Thus, it was found that both gold and chrome (having the most positive standard electrode potentials) were considered the least metallic, least bitter and least strong tasting of the spoons. Zinc and copper (having the most negative standard electrode potentials) were the strongest, most metallic, most bitter, and least sweet tasting of the spoons. We conclude that gold and chrome have tastes that are less strong than metals with lower standard electrode potentials. (C) 2011 Elsevier Ltd. All rights reserved.