Effects of Nasal Occlusion and Oral Contact on Perception of Metallic Taste from Metal Salts.

Iron and copper salts have complex olfactory and gustatory properties including a metallic flavor component that is decreased by nasal occlusion. To examine the sensory properties of ferrous sulfate and copper sulfate, a trained descriptive panel evaluated these compounds at equal molarity and perceived equal intensity with and without nasal occlusion. Ferrous sulfate exhibited a metallic taste and metallic aftertaste and copper sulfate exhibited a more pronounced metallic aftertaste.

Retronasal smell and detection thresholds of iron and copper salts.

Iron and copper salts, when placed in the mouth, may give rise to odorous compounds which complicate their functioning as chemical stimuli. The contribution of retronasal smell to perception of these metal salts at threshold has not been determined. Detection thresholds of the sulfate and chloride salts of ferrous iron and copper, and sodium chloride (as a control) were determined using a modified forced-choice ascending method of limits, with and without nasal occlusion.