A study published in the Journal of Food Science
shows that the aroma of dried bonito stock may improve the palatability of saltiness. Dried bonito stock is a traditional Japanese umami-rich stock that has a characteristic aroma.
Two pathways are available for the presentation of odors: the orthonasal and retronasal pathways. Retronasal olfaction is evoked by odorants released from the oral to the nasal cavity during chewing and after swallowing. Retronasal application of odors seems to evoke different sensations compared to orthonasal olfactory stimulation. In addition, retronasal odor is perceived less often as odor than taste and could thereby impact taste intensity. In this study, the researchers studied the effects of the retronasal odor of dried bonito stock on the enhancement and improvement of palatability upon salt reduction using sensory evaluation. Moreover, the contributions to flavor expression and palatability of dried bonito stock were also investigated.
To examine the influence of the retronasal odor of dried bonito stocks on saltiness enhancement, the researchers prepared five samples with varying percentages of NaCl combined with the retronasal odor of dried bonito stocks. In a second test, the panelists tasted ultrapure water with the retronasal odor of dried bonito stocks in order to examine the contribution of the retronasal odor of dried bonito stocks to their flavor and palatability.
The researchers found that although the retronasal odor of dried bonito did not enhance saltiness, it improved the palatability of saltiness. In the presence of no tastants except 0.68% NaCl, a content 15% less than that of Japanese traditional soup, the retronasal odor of dried bonito generated umami, enhanced the suitability for dried bonito stock, and increased palatability. This indicates that the retronasal odor of dried bonito stock could improve the palatability of a salt-reduced diet. The researchers concluded that these findings can be applied to the development of new seasonings for improving the palatability of salt-reduced foods.