Читать книгу Wine Faults and Flaws - Keith Grainger - Страница 75

Although highly sensitive, the receptors of taste buds can only detect five basic tastes: sweetness, bitterness, saltiness, acidity, and umami (the savoury taste of some amino acids). These are the non‐volatile compounds present in wine (although acetic acid is volatile). The fifth basic taste, umami, has only been recognised in the western world in 1985 and has only appeared in wine tasting notes in very recent years. There are claims of a sixth basic taste, the bitter, chalky taste of calcium, and other basic ‘tastes’, but such claims remain highly controversial. Trigeminal sensations, i.e. those detected by the trigeminal nerve, have recently come to be regarded in some quarters as yet another basic ‘taste’. However, these are not ‘tastes’, but sensations, e.g. the cooling effect of menthol/mint, or astringency. Of the five basic tastes, saltiness (comprising mainly sodium chloride) is usually not important in wine. The sensory cells of the tongue convert the detected tastes into electrical signals and send them to the brain's taste cortex. Until the late twentieth century, it was generally accepted that different parts of the tongue detect these basic tastes, and many wine‐tasting books and human biology texts still illustrate a diagram of the tongue detailing these areas. However, this concept has been discredited, largely by the work of Linda Bartoshuk when at UC Davis. For this chapter, I will rely on the approach that defined areas of the tongue are more sensitive to the individual basic tastes. It is not disputed that the ‘traditional’ areas of detection identify the tastes, only that the other areas do not. It is also accepted that the centre part of the tongue is considerably less sensitive to the basic tastes. There are tactile sensations of the wine that are also detected in the mouth, on the cheeks, teeth, and gums. These include tannin, body and alcohol, and the trigeminal sensations.