Trigeminal nerve (trigeminal nerve) is the fifth, very sensitive cranial nerve of the facial skull. It owes its name to its forking into three main branches, one of which also has olfactory functions. It conveys tactile sensations (concerning the sense of touch) of the facial region, which are perceived by the mucous membranes of the oral cavity and the nose when drinking wine or alcohol. These are irritating (irritating, arousing) sensations of a physical and less chemical nature. The trigeminal stimuli are a partial aspect of haptic perception. They are not typical sensations of smell or taste, although the effects are relatively strongly involved in the overall impression.
Trigeminal stimuli contribute significantly to the intensity of olfactory perception (about 30%). In smokers, the nasal-trigeminal sensitivity is reduced, the olfactory sensitivity is unaffected. Trigeminal stimuli can be both positive (alcohol, horseradish, menthol, carbonic acid, paprika, pepper, mustard, onion) and negative (ammonia, smoke, sulphur). A typical reaction to trigeminal stimuli is an increased salivary flow. If strongly expressed, this is a pain reaction and thus a precautionary warning signal of the body.
The capsaicin contained in paprika (chili, pepperoni) and the piperine contained in pepper cause the two trigeminal sensations peppery and pungent. The alkaloids, which are very similar in their effect, make the brain believe that the temperature in the mouth is critically high and create a feeling of burning in the heat-sensitive pain channels. The similarity of hot and hot (both called "hot" in English) when consumed is already based at the receptor level. The same receptors also react to heat stimuli above 43 Celsius, i.e. to food that is too hot, which "burns" the tongue or palate. The organism counteracts this sensation, which is often painful due to apparent heating, by increasing the blood circulation in the tissue for the purpose of heat dissipation. This leads to a local reddening as in the case of a light burn.
In the context of a wine address, the terms aggressive, astringent, biting, burning, pressing, hot, cold, cooling, peppery, sparkling, sharp, sparkling, pungent and stinging are used. Influences are mainly alcohol content (especially for distillates), bitterness, carbonic acid, acids, tannins and viscosity. These impressions are often confused with the sense of taste because they are also absorbed through the mouth. The term "mouthfeel" is also used for the trigeminal overall impression. Scientific research is being conducted at the University of California in Davis (California) and at the University of Adelaide (South Australia). The AWRI (Australian Wine Research Institute) developed a "mouthfeel wheel" analogous to the University of California's aroma wheel in 1998, which suggests 53 terms as nomenclature in the groups dynamics, taste nature, harsh, complexity, consistency, irritation, acidity, heaviness, texture, drying, immature, warmth and softness of the surface. See also under gustatory, olfactory and sensory
Picture left (edited): Copyright Peter Hermes Furian
Image right (edited): By NEUROtiker - own work, CC BY-SA 3.0, Link