Foods that burn (it ain't just chilli)...
As you may know, most chillies impart heat, it’s one of the many reasons we love them! In 1912 an American pharmacist named Wilbur Scoville developed the Scoville Organoleptic Test in order to determine the heat of a chilli. These days this test is now standardised as the Scoville Scale. In simple terms, Scoville’s scale was based on the number of parts of sugared water (to one part chilli) that was required before the heat was no longer detected. It’s a subjective measurement as the number of taste receptors in a humans mouth can vary from person to person. Nonetheless, this scale was highly commended, recognised by his peers and even won him pharmaceutical awards. He also had an awesome moustache that is very ‘en vogue’ at the moment! His scale is still in use today but modern science has allowed for this measurement to be more accurate and less subjective.
So, what makes a chilli hot? It’s a compound called capsaicin which serves as an irritant to us humans and mammals. Capsaicin is present in large quantities in the placental tissue of chillies (which holds the seeds), the internal membranes and, to a lesser extent, the other fleshy parts. The seeds themselves do not produce any capsaicin, although the highest concentration of capsaicin can be found in the white pith of the inner wall, where the seeds are attached. It’s a common misconception by many to think that chilli seeds are hot. It’s simply due to where they dwell within the fiery fruit!
Many chilliheads refer to the SHU (Scoville Heat Units) of their favourite chillies and chilli products but did you know that this scale is also used on another natural food? When we are giving talks and/or demonstrations at events, we sometimes ask the audience if they can guess which other food is measured in SHU. To date, no-one has guessed correctly. The answer is GINGER. Well, actually, there is another food too but we’ll address that in a moment.
The main active constituent of fresh ginger is a compound called gingerol which is a relative of capsaicin. It can reach up to 60,000 SHU however, the moment you cook ginger or dry it, its properties change and so does the SHU. For example, when ginger is mildly heated or dehydrated the gingerol forms shogaols which are more pungent than gingerol and can reach up to 160,000 SHU! To put it in perspective that’s 30-50 times hotter than a jalapeno. Cooking ginger makes gingerol transform in to zingerone which is less pungent and slightly sweeter. It’s all very scientific but interesting to know.
What about other foods that ‘burn’? Well, mustards, horseradish, radish and wasabi all ‘burn’ but in a different way. We’ll explain more shortly however, the other food we are missing that is measured in SHU is white/black pepper. Pepper contains a cuddly little compound called piperine. In pure form this alkaloid can reach an impressive 100,000 SHU. The amount of piperine in pepper is typically 5-10% but can be as low as 1%. So, whenever you meet a chilli wimp who claims that black pepper is too hot for them, there is some truth in their claim! A small amount of ground black pepper will hardly register on the Scoville Scale but it might just register nonetheless.
Some claim that cinnamon burns. Usually, this is because the person has experienced a cinnamon flavoured food such as Fireballs (hard candy) or flavoured bourbon. These foods usually contain cinnamon oil which contains cinnamaldehyde, eugenol and capsaicin. The latter is found only in very small amounts but is enough to offer up a burn to the consumer. In contrast, eugenol can have a slight numbing effect and can be found in other foods such as bay leaf, allspice and cloves.
If you have ever eaten mustard, horseradish, radish or wasabi you will have likely experienced a different type of burn to that of capsaicin. The heat isn’t so much in the mouth but in your nose. It’s short lived and can even make you sneeze! All of these foods contain a volatile compound called allyl isothiocyanate. Unlike capsaicin, it is unstable and vaporises at a low temperature of approximately 25 degrees. As most adult mouths sit at a higher temperature of 37 degrees, our bodies activate the volatile allyl isothiocyanate which becomes a gas which rises and agitates the mucus membranes in our noses. As capsaicin is a more stable oil, it sticks to the tongue and burns in the mouth rather than the nose.
We aren’t scientists, far from it in fact. However, we do like the idea of trying to produce a chilli, ginger, cinnamon and mustard sauce for a multiple burn sensation!