Keywords
Deliciousness; NaCl enhancement; Umami; Amino acid; Umami receptor; Dog; Human; Rat
Abstract
In the studies of taste receptor mechanism, rodents (rats and mouse) have been usually used. However, taste responses of rodents are quite different from ones of humans. In a mixture that has the taste of crab meat, sodium chloride is an essential ingredient in addition to three amino acids and umami substances. Withdrawing the sodium chloride from the mixture results in a very weak taste because sodium chloride has the ability to enhance the other taste stimuli. However, in the rodent taste system, sodium chloride has no enhancing effect on the other stimuli. In the canine taste system, sodium chloride greatly enhances the responses to amino acids, sugars, and umami substances as it does in humans. Withdrawal of umami substances from the mixture with the taste of crab meat leads to a taste that is quite different taste from the crab meat taste. Umami substances are contained in many foods such as seaweed, bonito, sardine, tomato, mushroom, cheese, cured ham, and mother’s milk. Furthermore, various soup stocks contain height content of umami substances. It is difficult to achieve good flavors without umami substances. There are three umami substances (glutamate, 5’-inosinate, and 5’-guanylate). There is synergism between glutamate and 5’-inosinate and between glutamate and 5’-guanylate. The response to umami substances alone is rather small, but the response elicited by this synergism is very large. In humans, the response elicited by the synergism is the main umami response. In rodents, the umami response elicited by the synergism is very small, but it is very large in dogs, as with the response in humans. The reason that the canine taste system resembles that of humans is that dogs have been eating the same foods as humans in the past 15,000 years, and the canine taste system has assimilated to the human taste system.
Citation
Kurihara K (2020) Canine Taste Responses to Elements of Food Deliciousness Closely Resemble Those of Human Responses, While Rodent Responses are Very Different from Canine Responses. SM J Nutr Metab 6: 9. doi: https://dx.doi.org/10.36876/smjnm834643Kenzo Kurihara, Aomori University. Aomori, Japan; E-mail: kenweiss@upenn.edu