The foundations of any flavor are the involatile chemicals dissolved in saliva and detected in the mouth, commonly called the basic tastes. Unfortunately, a widely propagated misunderstanding is that the basic tastes are perceived only on certain locations on the tongue. This is not true. Although some regions are more sensitive than others, tastes can be perceived over much of the tongue, as well as on other soft oral surfaces, such as the palate and the throat. We also now recognize the need to expand the four basic tastes that have long been recognized (sweet, salt, sour, bitter) to include umami, the sensation from MSG and other flavor enhancers. The importance of the contributions of these stimuli to flavor should not be underestimated. For example, bitterness in the right context (such as coffee and beer) is essential to enjoyment, yet, in the wrong context, it is a source of consumer complaints. Sensitivity to bitterness is a genetic factor, and three populations have been identified (non-tasters, tasters and supertasters), giving new product development (NPD) teams an uncomfortable consumer segmentation to address. In addition, it becomes even more complicated when realizing that the segments can differ in different ethnic groupings.
Perhaps more research has been carried out into sweetness response than any other basic taste (not surprising, in view of our inherent liking for sweetness). The understanding also has been driven by the perceived need to reduce dietary sugar, and the consequential need to address the taste defects that often afflict sugar replacers based on intense sweeteners. Work carried out at Leatherhead Food International (Surrey, U.K.) as part of E.U.-funded projects has identified design strategies that can be used to minimize unwanted tastes and to maximize sweetness quality. (See “A Design Strategy for Sweetness Quality” chart.)