A couple of weeks ago, while you were sitting at home watching telly, you may have acquired another taste, to add to the other five.
For a long time, we all rubbed along with the traditional foursome of sweet, sour, salty and bitter. We were content; we knew no better. But in 1908, Kikunae Ikeda, a chemist at Tokyo Imperial University, claimed to have discovered a new taste: umami. Trying to figure out what gave his dashi soup its singular taste, he eventually concluded that it was a particular amino acid, called glutamic acid, usually found in monosodium glutamate (MSG).
His claims were widely dismissed – though the sale of MSG still became a mult-million pound business – until the discovery of glutamate receptors on our tongues decades later.
Now, a series of articles in the scientific journal Flavour give credence to the suggestion that there is a sixth flavour. Called kokumi (the word is a confection of the Japanese words for "rich" and "taste") it has been mooted since the 1980s, but is only now gaining ground in the scientific journals.
So what does it taste like? Hard to say, but the suggestion is that it is as much a mouth feel as a taste. Scallops, onions and garlic and yeast extract are supposed to have it in abundance.
The "it" in this instance comprises chemicals called gamma-glutamyl peptides (a simple description is 'a group of small molecules that, when clumped together, are the building blocks from which proteins are built').
The thing is, although these peptides have been identified, it is a matter of debate as to whether the "taste" we experience is a bona fide psychological experience, rather than a scientist's daydream.
Why? Because, as yet, no gamma-glutamyl peptide receptor cells have been detected on the human tongue. It would be with these biological landing pads that the kokumi would be detected, thus creating a corresponding "taste" sensation in the brain.
The paper in Flavour also raises another intriguing possibility.
The study, written by Dr Motonaka Kuroda, suggests that the addition of kokumi to foods may help reduce fat intake. A variant of gamma-glutamyl peptide was added to consommé and peanut butter. In each case, taste testers found the food with the peptide chains more palatable and mouth-coating.
The hope is that these peptide chains will become a new version of MSG – though, unlike MSG, which is used to make low-salt foods more agreeable, this could potentially be used to make low-fat foods more palatable. At the moment, the way most manufacturers do this is by adding sugar, a process linked to an increase in cases of type-2 diabetes.
Before we start rejoicing, a note of caution – there is a long way to go before it is officially accepted as the sixth taste. There is some suggestion it may just simply be another form of umami, with the "effect" simply an amplification of that existing taste, rather than a wholly new phenomenon.
That said, there is an increasing bank of studies pointing to its existence. The research may be in its infancy, but if it grows big and strong, kokumi could soon become your next cupboard essential.Reuse content