Detection thresholds and taste qualities of iron salts

In previous work, the possibilities of retronasal and tactile qualifier of ferrous sulfate were assessed. To provide a detailed description of properties of ferrous salts, more basic psychophysical tests of iron salts were carried out. The first study examined detection thresholds of three ferrous salts. Average detection thresholds for ferrous sulfate, chloride and gluconate were 99.2, 66.0 and 20.5 mu M, respectively. A second study examined the taste qualities of same iron salts at different concentrations with and without nasal occlusion. The total intensity and taste qualities of iron changed as a function of concentration and anions. These results confirm that the sensations of ferrous salts are a complex of retronasal, gustatory and possibly tactile cues. Furthermore, the taste of their salts can be described by a combination of four basic tastes as well as metallic and astringent if only these terms are available to the subjects. (C) 2005 Elsevier Ltd. All rights reserved.