Nestlé Scientists Uncover the Complexity of Taste

The researchers found that metallic-tasting salts activate numerous signaling pathways, with the resulting taste perceptions depending upon the salt concentration.

20/03/09 Scientists from the Nestlé Research Center, Lausanne, Switzerland, in collaboration with colleagues at the Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland, and Duke University, United States, made a contribution to elucidate the mechanisms of complex taste sensations.

Salts of iron, zinc, copper and magnesium are present in our daily diet and often impart a metallic taste. The multi-dimensional taste and sensory profiles, and the mechanism of how these salts stimulate taste receptors is not fully understood. Nestlé scientists want to decipher these mechanisms of taste and the signaling pathways involved in complex sensory perceptions.

In this study, Nestlé researchers investigated the T1R3 taste receptor (which is involved in the detection of sweet and umami tastes), the TRPM5 channel (involved in identifying bitter, sweet and umami tastes) and the TRPV1 receptor (detecting spice and heat). All these proteins are found in the taste buds on the tongue. Results showed that iron and zinc create a positive response at low concentrations, mediated by T1R3 and TRPM5, and an aversive response at high concentrations.

Copper and magnesium, two primarily bitter-tasting compounds, are avoided at both low and high concentrations, to a large degree mediated by TRMP5 and TRPV1 containing pathways.

In summary, the researchers found that metallic-tasting salts activate numerous signaling pathways, with the resulting taste perceptions depending upon the salt concentration. These results expose two important paradigms: 1) Our tongue detects much more than the five classical tastes (sweet, sour, salty, bitter and umami). Instead, taste perception is a dynamic interplay between the gustatory and trigeminal systems (T1R3, TRPM5 and TRPV1, respectively), as evidenced by the complex tasting metallic salts. 2) The study connects taste modalities, tastant concentrations and perceived preference or aversion on both the cellular and molecular levels.

“It is vitally important for us at the Nestlé Research Center to understand the physiology behind taste perception, especially of these complex molecules,” said Dr Johannes le Coutre, Head of the Perception Physiology group at the Nestlé Research Center. “Through our work in this area, we support Nestlé’s ongoing mission to offer consumers foods that are both nutritious and have a great taste.”

Article Reference:
Riera CE, Vogel H, Simon SA, Damak S, and le Coutre J. Sensory Attributes of Complex Tasting Divalent Salts Are Mediated by TRPM5 and TRPVI Channels. The Journal of Neuroscience. 2009;29(8):2654-2662.