Pungency

The primary substances responsible for pungent taste are capsaicin, piperine (in peppers) and allyl isothiocyanate (in radish, mustard and wasabi).

[1][2][7] For instance, a pumpkin pie can be both hot (out of the oven) and spicy (due to the common inclusion of spices such as cinnamon, nutmeg, allspice, mace, and cloves), but it is not pungent.

The Scoville scale measures the pungency of chili peppers, as defined by the amount of capsaicin they contain.Pungency is not considered a taste in the technical sense because it is carried to the brain by a different set of nerves.

While taste nerves are activated when consuming foods like chili peppers, the sensation commonly interpreted as "hot" results from the stimulation of somatosensory fibers in the mouth.

Substances such as piperine, capsaicin, and thiosulfinates can cause a burning or tingling sensation by inducing a trigeminal nerve stimulation together with normal taste reception.

[1] Capsaicin evolved in peppers to deter particularly seed-eating rodents that destroy seeds by grinding, thwarting their germination, while at the same allowing birds to eat them and disperse through much greater distances via defecation, thus also preventing the new seedlings from competing for natural resources with their parent plant [10] (in birds, pepper seeds are not destroyed by consumption and digestion).