Dried-bonito aroma components enhance salivary hemodynamic responses to broth tastes detected by near-infrared spectroscopy.

To elucidate the effects of aroma from dried bonito (katsuo-bushi) on broth tastes caused by the central integration of flavor, optical imaging of salivary hemodynamic responses was conducted using near-infrared spectroscopy (NIRS). A reconstituted dried bonito flavored broth produced a significantly larger hemodynamic response than the odorless broth taste solutions for 5 of the 10 panelists, who felt that the combination of the aroma with the tastes was congruent. In the remaining 5 panelists who felt the combination incongruent, the flavored broth did not cause the enhancement of response. Moreover, when the odor-active smoky parts were removed from the flavoring, the reconstituted flavoring did not enhance the response in the former five panelists. These results indicate that NIRS offers a sensitive method to detect the effect of specific congruent aroma components from dried-bonito broth on the taste-related salivary hemodynamic responses, dependent on the perceptual experience of the combination of aromas and tastes.