pungency

Pungency or irritation is described as a type of chemesthesis, the broader chemical sensitivity of skin and mucous membranes, rather than a basic taste mediated by taste buds. The irritation felt in the mouth and nose is described as carried by somatosensory nerve fibers of the trigeminal, glossopharyngeal, and vagus nerves. Different irritants act through different ion channels: capsaicin and piperine through TRPV1; allyl isothiocyanate (mustard oil), allicin, and cinnamaldehyde through TRPA1; and menthol and eucalyptol through TRPM8. Whether TRPV1 is expressed in taste-bud cells themselves remains unresolved.

This irritation also occurs in some foods closely associated with bitterness. A review says many, though not all, isothiocyanates produced by hydrolysis in the mustard family impart pungency. Spilanthol and related unsaturated fatty-acid amides are described as evoking a broad range of somatosensory experiences—pungency, prickling, buzzing, numbness, salivation, and cooling—with pungency listed first.

Oleocanthal in freshly pressed extra-virgin olive oil is another example of this irritation. In a study of 12 human participants, participants reported little irritation from olive oil at the front of the tongue but strong irritation at the back of the throat, unlike horseradish or allyl isothiocyanate, whose irritation spreads widely through the mouth. Before the compound was named oleocanthal in 2005, a fractionation study of olive-oil polyphenols had identified the fraction causing intense burning irritation in the back of the throat as deacetoxyligustroside aglycone; the 2005 report independently described this irritation by analogy with an ibuprofen solution.