According to a study published in the recent issue of Journal of Biological Chemistry, Japanese researchers at Ajinomoto Inc. have proven that calcium channels on the tongue are closely related to the receptors that sense sweet and umami (savory) tastes, and that glutathione—a common kokumi (loosely: heartiness) taste element—interacts with calcium channels.
When reached by Perfumer & Flavorist magazine for comment, Ajinomoto’s Naoko Obara said, “We are expecting to accelerate product development by utilizing such ‘kokumi technology’ with calcium sensing receptor (CaSR). However, specific plans have not been determined yet.”
Yuzuru Eto and colleagues from Ajinomoto created several small molecules that resembled glutathione and analyzed how well these compounds activated calcium channels in cell samples. Then, they diluted the same test substances in flavored water (salt water, sugar water, etc.) and asked volunteers (all trained in discriminating tastes) to rate how strong the flavors were. The results provided a strong correlation; the molecules that induced the largest activity in calcium receptors also elicited the strongest flavor enhancement in the taste tests. For further confirmation, the researchers tested several other known calcium channel activators, including calcium, and found all exhibited some degree of flavor enhancement, while a synthetic calcium channel blocker could suppress flavors.
This study provides new insights into the areas of taste biology, and could have practical uses in food modulation, for example, in creation of healthy foods containing minimal sugar or salt but still eliciting strong taste. At the moment, however, the mode of action for these substances is poorly understood.