NARO has discovered a sweet-tasting compound among the aroma components found in fruits. In collaboration with Kyushu University, Tokyo Dental College Junior College, University of Tsukuba, and the Institute for Protein Research at Osaka University (formerly Okayama University at the time of the study), NARO has revealed a unique mechanism by which hydrophobic sweet-tasting compounds, including the newly identified one, bind to the same sweet taste receptor as water-soluble sweeteners, but at different binding sites. Interestingly, in mice, these compounds act as sweet taste inhibitors.
Until now, there has been little research on hydrophobic sweet-tasting compounds, and their use as sweeteners had not been considered. However, this discovery paves the way for the development of novel non-sugar natural sweeteners, contributing to both palatability and health by promoting reduced sugar content in foods.
Overview
Sweet-tasting substances are generally considered to be water-soluble, like sugar. However, it has been known that plants contain low-molecular-weight hydrophobic compounds, such as aroma components, that can elicit a sweet taste. These compounds are often mistaken for simply having a sweet aroma, and the actual mechanisms by which they elicit a sweet taste had not been fully understood.
In this study, NARO explored aroma compounds and discovered that trans-2-hexenal, found in fruits and vegetables such as apples, possesses sweet-tasting properties.
Additionally, in collaboration with Kyushu University, Tokyo Dental College Junior College, University of Tsukuba, and the Institute for Protein Research at Osaka University (formerly Okayama University at the time of the study), NARO analyzed the binding sites of trans-2-hexenal and other known low-molecular-weight hydrophobic sweet-tasting compounds on the sweet taste receptor. The study revealed that these compounds bind to different sites than those used by water-soluble sweeteners such as sugar.
Furthermore, experiments in mice confirmed that these compounds either do not elicit a sweet taste or, conversely, suppress the sweetness perceived from other sweet-tasting substances.
These findings open new possibilities for food design by utilizing sweet-tasting aroma compounds as sweeteners. In particular, combining them with natural sweeteners such as sugar is expected to enable the development of low-sugar foods and beverages with a more natural sweetness.
Publication
Horie F, Sanematsu K, Yasumatsu K, Hirokawa T, Shigemura N, Yamashita A and Kusakabe Y (2025) Receptor mechanism producing a sweet taste from plant aroma compounds. Scientific Report. 15, 6795. https://doi.org/10.1038/s41598-025-89711-9
Related Information
Budget: This research was supported by a JSPS KAKENHI Grant (JP24K08760) and the Tokyo Dental College Research Grant (Well-being Project).
