Until relatively recently, our understanding of how we perceive flavour was limited to four basic tastes: Salty, sweet, sour and bitter – and it was also limited by the pervasive myth of the ‘tongue map’, which erroneously suggested that some basic flavours were exclusively tasted by different parts of the tongue. In fact, taste buds anywhere in the mouth can taste all kinds of flavours.
In 1985, nearly 80 years after a Japanese chemist first proposed its existence, flavour scientists officially recognised umami as the fifth basic taste – and it seems there may be others.
Just last year, US researchers published a paper suggesting that fat may be sensed in the mouth in the same way as other basic tastes, upsetting the earlier belief that fat perception was nearly entirely dependent on textural and aromatic cues.
And in 2007, researchers found that we may ‘taste’ food in the gut, as well as on the tongue (and in the nose) – not consciously, but receptors in the intestine may promote insulin secretion or mean we find a sweet food more satisfying. Earlier this year, Belgian researchers suggested that targeting intestinal taste receptors might be useful in the fight against obesity.
"Targeting extra-oral taste receptors that affect the release of hormones that control food intake may offer a new road to mimic these effects in a nonsurgical manner," they wrote in Trends in Endocrinology & Metabolism.
So what is the food industry doing with all this new information?
Senomyx is one company at the forefront of flavour technology that uses our understanding of taste receptors to optimise the flavour of certain ingredients – and to mask some of their less desirable flavour notes, such as bitterness in a sweetener.
Senomyx’s research into sucrose enhancement in particular has gained a lot of attention, as food and beverage manufacturers look for ways to cut sugar and other nutritive sweeteners in their products without sacrificing flavour. It has several enhancers tailored to different nutritive and non-nutritive sweeteners that work by making sweet taste receptors more efficient, thereby giving the impression of greater sweetness without increasing sweetener quantity.
The California-based company also has ingredients that work with other tastes, including four savoury flavours, recently approved for use in the EU.
‘A real receptor-based discovery engine’
Major food and drink companies are paying attention. At the Research Chefs Association conference in the US earlier this year, PepsiCo’s chief scientific officer Dr Mehmood Khan said that R&D teams should be taking note of taste perception discoveries.
“We want to fuse world class molecular biology, chemistry and sensory science, and transform our R&D department from a new product development engine to a real receptor-based discovery engine,” he said.
The hunt continues…
However, the hunt for ingredients that capitalise on our increasing understanding of taste is far from over.
Unilever, via its open innovation portal, is seeking partners to help meet its salt and sugar reduction goals, with “technologies that address sensory and taste perception”.
Meanwhile, General Mills has said it is seeking a novel approach to suppress the sour taste of some organic acids.
“Specifically, organic acids contribute to the activation of ion channels in taste cells associated with sour perception. Additionally, in many food systems acidic levels can increase through the shelf-life of the product,” it says on its G-WIN open innovation platform.
“We seek technologies to block the perception of sourness of lactic acid, citric acid and malic acid at the receptor channels and/or ingredients that mask sourness perception.”