herbsandspices.food The reference guide to herbs and spices

🔬 Science

Capsaicin, the Scoville scale, aroma compounds and the coriander gene.

12 pages in this section

Aroma compounds in herbs and spices
Terpenes, phenylpropanoids and the handful of molecules behind most of the spice rack
Most of what herbs and spices taste of is really smell. A few families of volatile molecules, chiefly terpenes and phenylpropanoids, account for the characteristic aroma …
Capsaicin
The molecule that makes chillies hot, and why the heat is an illusion
Capsaicin is the main compound behind the heat of chillies. It triggers the TRPV1 receptor, the same sensor that detects scalding heat, so the mouth reports a burn that i…
Curcumin
Turmeric's yellow pigment: a dye, a pH indicator and a much-studied molecule
Curcumin is the yellow pigment of turmeric. It is a vivid food colour and natural pH indicator, and although heavily researched, very little of it is absorbed by the body…
Fat and flavour
Why spices are fried in oil, and why milk beats water for a chilli burn
Most spice flavour and colour compounds dissolve in fat far better than in water. That simple fact explains tempering, blooming, chilli oil, dairy against chilli heat and…
Menthol and cooling
How mint persuades the mouth that it is cold
Menthol feels cold because it switches on TRPM8, the nerve receptor that detects cool temperatures. The effect is a sensory trick: menthol does not lower the temperature …
Mustard oils
The heat that goes up your nose: mustard, horseradish and wasabi
Mustard, horseradish and wasabi get their heat from isothiocyanates, the mustard oils. They form only when the plant's cells are damaged, and they trigger TRPA1, the rece…
Piperine
The bite of black pepper, and a molecule that dislikes the light
Piperine gives black pepper its bite. It acts on the same heat receptor as capsaicin, far more weakly, and slowly loses its pungency when ground pepper is exposed to ligh…
Sanshool and tingling
Why Sichuan pepper makes lips buzz like a phone on silent
Hydroxy-alpha-sanshool, found in Sichuan pepper, makes lips and tongue tingle and go numb. It fools touch receptors into firing as if the skin were vibrating at around 50…
Spice tolerance
Why some people eat vindaloo for breakfast, and how the rest can catch up
Regular chilli eaters genuinely feel less burn. Repeated capsaicin exposure desensitises heat-sensing nerves, while habit, culture and a taste for thrills explain why peo…
Spices and food preservation
Did hot countries learn to spice their food to keep it safe? The antimicrobial hypothesis
Many spice compounds slow the growth of bacteria in the laboratory. Whether that explains why hot countries use more spice, as Sherman and Billing proposed in 1998, remai…
The Scoville scale
From a panel of tasters in 1912 to a machine that counts molecules
The Scoville scale measures chilli heat in Scoville heat units. It began in 1912 as a dilution taste test; today the capsaicinoids are measured by HPLC and converted to t…
Why coriander tastes of soap
Aldehydes, a smell receptor gene and one of the kitchen's great divides
For a minority of people coriander leaf tastes of soap. The leaf is rich in aldehydes also used in soaps, and a genetic variant near the smell receptor gene OR6A2 is link…