Among all the spices found throughout the world, a minority brings a more or less intense sensation of spiciness depending on the spice. These spices which bring heat and spice can be classified into what we call fire spices. You will of course find peppers, chili peppers but also ginger, mustard, wasabi for the best known.
Surprisingly this family represents a minority of spices. There are approximately 4 to 500 products used as spices in the world, only a few bring fire. But this minority, due to its unforgettable characteristic on the one hand and the fact that they are used frequently and all over the world, mean that they inevitably take an important place in the kitchen. Even at the risk of causing some confusion between spicy and spicy! (see article Spicy or Hot? )
But then why does it sting?
Pepper and piperine
Pepper, or rather piper peppers , all contain a molecule responsible for the heat released in the mouth: piperine . Discovered in 1819 by the physicist-chemist Hans Christian Ørsted, it is found in all these peppers but curiously also in a mushroom: the Peppered Boletus or Chalciporus piperatus . This cep does not present much interest in being eaten like a Bordeaux cep, its piperine level being very high. It would be like taking a tablespoon of peppercorns. However, it can be picked to be dried, reduced to powder to serve as a peppery condiment, or even a substitute if you lack pepper!
Piperine, concentrated in the kernel of the pepper grain, is measured on the Scoville scale (see article Scoville scale ). Pure piperine has a level of 100,000 compared to the level of 16,000,000,000 of pure capsaicin found in chili peppers.
Chili pepper and capsaicin
Chili pepper is the most consumed spice in the world. It is found on all continents. Originally from Central America, it then followed a particular route passing through Portugal, India and then Asia, then Europe before returning to America (North and South). (article The long journey of chili )
The spiciness is caused by an alkaloid: capsaicin. Concentrated between 0.1 and 1.5% in chili peppers, depending on the variety, it causes a spicy sensation when it comes into contact with the mucous membranes of the mouth.
It has also been proven that we get used to chili peppers for physiological reasons. The person responsible is the receptor of this sensation, TRPV1 which, through habituation, becomes disinhibited. Which explains the vision of children in Mexico regularly eating chili peppers for example. When we think of Asia, their often spicy cuisine is completely bearable and very appreciated! So don't despair if you can't tolerate chili, just eat it often...
Finally, capsaicin is fat-soluble, it only dissolves in fatty substances. So if a pepper irritates you, then absolutely don't have a glass of water but a glass of milk, or yogurt or cheese!
Ginger and Shogaol & Gingerol
Ginger is also one of the fire spices, it brings heat with a slightly peppery sensation. The culprit, or rather the culprits, are two compounds: shogaol and gingerol . The first derives from the Japanese (生姜、shōga) which simply means ginger. This compound on the scoville scale has a rate of 160,000 compared to pure capsaicin's rate of 16,000,000,000. It is mainly responsible for the notion of heat released by ginger. It is then supported by the second compound gingerol, chemically close to capsaicin.
Wasabi, Mustard, Horseradish and Sinigrin & Allyl Isothiocyanate
Another family in which we find a sensation of spiciness: those of the Brassicaceae . We find mustard, wasabi and horseradish.
Sinigrin causes the stinging sensation . As for Allyl Isothiocyanate, it causes both the spicy sensation and the sensation of mustard “going up to the nose”. The effect occurs later, the molecule volatilizes in the mouth, passes through the throat and ends up in the nose. It stimulates touch receptor neurons which gives this particular sensation.
When grinding mustard seeds, two molecules, sinigrin and myrosinase, are mixed. The latter allows the cutting of sinigrin by water molecules. The result is a new compound: Allyl Isothiocyanate. This explains why mustard seeds can only sting intensely if they are finely ground. The finer the grind, the stronger the mustard will be. Hence “old-fashioned” mustards where the grains are not completely crushed and are not very spicy.
It is interesting here to note a defense mechanism of nature: mustard protects itself from predators eager to taste these seeds!
Zanthoxlyum and Alpha sanshool & Alpha hydroxy sanshool
Finally, last family we find a sensation more of heat than of spiciness: the Zanthoxylum . (Timur Pepper, Peak Pepper, Sichuan Pepper, Sansho Pepper for the best known). The sensation caused is not quite a stinging sensation but more a sensation of pseudo-heat accompanied by a phenomenon of paresthesia (anesthesia of the mouth). The two compounds (whose name derives from the Japanese Zanthoxylum , Sansho) Alpha sanshool & Alpha hydroxy sanshool are responsible.