Domestic cats have the required ‘umami’ taste receptors on their tongues to respond well to an enzyme called inosine monophosphate and an amino acid called free L-Histidine which combine to produce a strong umami taste.
Cats enjoy these taste receptors thanks to the inheritance of Tas1r1-Tas1r3 genes.
The umami taste is described as the fifth taste in addition to bitter, salty, sweet and sour. Umami is also described as a savoury taste or ‘meaty’ and ‘delicious’.
Umami is a Japanese word pronounced ‘oo-ma-mee’.
A study recently published came to the above conclusion. It is called: Umami taste perception and preferences of the domestic cat (Felis catus), an obligate carnivore. The link to the study is: https://doi.org/10.1093/chemse/bjad026.
P.S. Canned tuna contains added salt in pretty high concentrations. It does not contain added sugar on my research. Cats like salty flavours. As a treat tuna is fine in modest amounts only because of the high salt content and it is not a balanced feline food.
P.P.S. There is an environmental issue to be aware of. Tuna stocks in the oceans are depleting as they are overfished. For instance, yellowfin tuna is on the brink of extinction. Bluefin tuna stocks are in danger of collapse and cannot be fished more intensively. When buying tuna, we should think of these things. I don’t buy canned tuna.