Capsaicin and capsaicinoids

Chilli Chemistry 101.

Here we go with the science behind why our mouths seem on fire when we eat chillies…

Individual chilli varieties, plants, pods and even parts of pods all contain varying amounts of capsaicinoids. These are the compounds responsible for the hot sensation when we eat chillies. Capsaicin is the main capsaicinoid found in chillies, although there are others. Inside a chilli fruit, the highest concentration of capsaicinoids can be found in the join between the membrane lining of the chilli wall and the whitish pith where the seeds are attached. This is where the capsaicin glands lurk, waiting to ambush an unsuspecting cook.

Each part of the chilli pod has different levels of capsaicin.

The capsaicinoid compounds share a significant quality. They are able to enter and alter the TRPV1 ion channel in mammals. They lock the receptors open until the capsaicinoid molecules have moved on. TRPV1 receptors are responsible for detection and regulation of body temperature over 42 degrees. The receptors can be found at many points within mammals bodies, and are particularly sensitive where there are mucus membranes. When we eat chillies, it is the TRPV1 receptors in our mouth that respond with the oh so familiar burning sensation. Capsaicinoids trick our body into thinking we have touched something dangerously hot.

Is it just chillies, or do other plants produce capsaicinoids?

There are some real bad ass plants out there. Resin Spurge (Euphorbia poissonii) for example produces a compound that is up to 1,000 times more potent than capsaicin. So pungent that even in tiny amounts it renders the recipient seriously neurologically damaged, and can be fatal. Luckily for chilliheads, capsaicin levels found naturally in chillies do not cause physical damage, just a physical response.

Resin Spurge Euphorbia poissonii

Another member of the Capsaicinoid Gang can be found in ginger: gingerol. It measures lower on the Scoville Scale than capsaicin which explains the milder seeming heat of ginger. It fact gingerol becomes even milder if cooked long or at a high temperature. Be warned though, as a gentle warming or drying of ginger can double the spiciness of gingerol.

Foodies will also be familiar with the aromatic heat of peppercorns. This is caused by a capsaicinoid called piperine. Perhaps it was the early love of piperine that allowed the capsaicin rich chillies to steal our hearts when they were finally unleashed on the old world.

There are also other capsaicnoids to be found in chilli peppers. Nonivamide is one of these. It is synthesised and used in the food industry to add pungency and heat. It is cheaper to do this than extract and use naturally occurring nonivamide or capsaicin. It is also the main constituent of pepper spray.

Why have capsaicinoids developed in plants?

Most people seem to agree that it is in the interest of deterring mammals. Plants do not want to be eaten by animals that will destroy their seeds. Simple but are there other reasons too?

What about animals? Do they use capsaicinoids?

It turns out that the animals have got the hang of making chemical triggers for the TRPV1 receptors too. Certain tarantulas of West Africa, specifically the Earth Tiger tarantula, make a toxin that works on the TRPV1 receptor causing pain in the form of intense heat.

Earth Tiger tarantula

Obviously Mrs Earth Tiger doesn’t want to be chewed up and spat out by a furry mammal. Not so good for future generations of baby Earth Tigers. Chemical weapons at the ready then.

The use of capsaicin as a deterrent is not only employed by plants but by used by humans as well. The aforementioned pepper spray is a good example of this. And, a quick look at an image taken from the Codex Mendoza, created in the mid 1500s, reveals a child being held over a fire of burning chillies. The child’s eyes are streaming. It is perhaps a punishment: a deterrent for some undesirable behaviour. Y’owch, tough love but they’ve gotta learn!

Taken from the Codex Mendoza

But back to the chilli plant’s use of capsaicin as a deterrent…

The biological motivation of chilli plants is a little more complex. Many plants are interested in animals eating their fruit as a manner of seed dispersal. But chilli plants are producing a chemical that actively deters mammals. So what is wrong with mammals? Ah, they have grinding molars. Poor little chilli seeds are unlikely to survive after a good grinding. Most mammals will avoid plants which make their mouth burn so the chilli seeds are safe to be eaten by non-mammals.

It turns out that birds are just the insensitive little blighters required… insensitive to capsaicinoids that is. It makes sense that chilli plants don’t deter their feathered friends as birds’ feeding habits are exactly exactly what a chilli plant needs. Bird sees brightly coloured, yummy looking fruit. Bird eats fruit. Seeds pass through digestive system pretty much intact. Bird flies off. Seed deposited with a healthy dose of Mother Nature’s own fertiliser. Job’s a good’un.

That sounds like the right reason for capsaicinoids to be in chillies.

Ah, but animals are not the only consumer of chillies. Microbial level interference is just as likely to stop the chances of a chilli plant producing viable seed as hungry animals are. Fungi and bacteria in particular are able to negatively affect chilli plants’ growth. Which leads to the revelation of another super power of capsaicinoids. They are highly anti-microbial.

It has been theorised and widely accepted that wild chilli plants survive to produce ripe seed pods when their pods have a higher dose of capsaicin lurking within. This capsaicin presence seems to deter certain fungus from taking up residence in the plants and affecting their crop.

Other capsaicinoids deter different fungi in a range of ways. Some act on fungi on the roots, others on fungi on the leaves. The percentage and balance of capsaicinoids present in individual species of chillies correlates with exposure to specific fungus. So Ecuadorian rainforest chillies have different capsaicinoid levels to Andes Mountain rocoto chillies as a result of the microbes present in their respective environments.

Chillies are super anti-bacterial. Capsaicin inhibits the growth and survival of about 75% of bacteria out there in the world. Once the chilli plant has reached maturity it has a high enough concentration of capsaicinoids to inhibit bacterial attack. Bang, and the germ is GONE!

The anti-microbial quality of capsaicinoids goes a long way to explain why chilli is a very popular traditional ingredient in hot countries. Back in the days before fridges, the anti-bac effect of chillies would have stopped food from spoiling. Recipes would have included chilli as a preservative and preventative to food poisoning. Good recipes are always passed down. Bad recipes might have resulted in no one surviving to pass recipes down to.

It’s beginning to look like a lot like chillies and their capsaicinoid compounds are rather well equipped to take over the world with their tailor-made toxic toolkit. Oh, too late, they already have.

With such potency to be found in these compounds there must a be a way for modern humans to utilise the power of chilli.

Initially, when the portuguese explorers brought chillies home they were appropriated by monks and grown as a medicinal herb. What on earth did they use them for and what could they be useful for these days? Listed below are a few medical and health claims, not substantiated, just an indication of the impact capsaicin could have in our future:

  • Consumption of chilli before a meal can significantly reduce calorie intake. Capsaicin has an effect on the ‘fullness’ receptors in our stomach.
  • Topical application of capsaicin loaded creams can alleviate arthritic pain, shingles neuralgia and even HIV neuropathy. The Aztec folk used it as a pain reliever for toothache. The capsaicin is said to deplete the quantity of Substance P (one of the body’s pain messengers).
  • Capsaicin has been touted as a dietary control for cholesterol. Targeting the bad cholesterol that clogs up arteries whilst leaving alone the good stuff that clears them.
  • Psoriasis lesions that itch can be alleviated by the application of capsaicin creams. This pain relief is temporary but improves with regular use.
  • Eating a normal amount of chilli in a meal can reduce the quantity of insulin required by your body to deal with the intake of sugars.
  • The heat pain from a chilli can distract the body from other pain, e.g. migraine.
  • Capsaicin is also heralded as an anti-cancer hero. It can cause cancerous cells to go into defence mode and self-destruct in their efforts. Thus causing a halt in growing tumours.
  • Increased blood flow and thinning qualities as a result of eating chillies, all mean that heart disease and stroke are less likely.
  • Generally, people who eat chillies are 13% less likely to die before those who don’t eat chillies. Perhaps 100% true.

So why did humans develop a taste for chillies, despite the burn?

Maybe as a survival technique. It has been indicated that in the past, if you lived in an area where you are at risk of microbial infection and ultimately death, increasing the use of chillies reduced fatality. Communities who use more chilli in their cooking survived to tell the tale.

And then there is the chilli high. The body’s endorphin rush response to the attack of chillies. The thrill seekers and risk takers will recognise similarities in the rollercoaster of emotions a hot chilli hit brings compared to that of their thrill of choice. We feel good that we survived the chilli onslaught. We’ve survived to eat another mouthful of the hot stuff. It feels good to be alive!

Capsicum pubescens

Capsicum pubescens is a late entry to the heated propagator. Whilst using the last of our homegrown Rocoto chillies it was impossible to just throw the seeds away. So, they were introduced to the chitting pod. Having sworn we would get going earlier with the seeds this year, to allow the longest growing period possible, a quick diary check reveals that these seeds are starting off at pretty much the same time as last year. So much for planning.

Alberto Locato Rocoto

Four days later the roots have emerged. Much quicker than the chinense types and almost as quick as the speedy annuums.

chitted-rocoto-chillies
Chitted Rocoto seeds

And why did we bother with these seeds? Well, it turns out we’ve got a bit of a crush on these squishy fellas. There are far less varieties of Capsicum pubescens available on the market and you would certainly never see them in a UK food store to buy. The chilli fruit are all pretty similar with thick walls, juicy flesh and matt black seeds. With a round shape: some are a little more apple shaped, others lemony and some occasionally cheeked like bell peppers. Heat levels are medium to hot and they have a punchy fresh fruit flavour. They come in a range of -green-yellow-red but not purple or white. So far.

Capsicum pubescens are the smaller group of the five domesticated species of chilli. They are further away from others genetically. They trace back to pre-Incan times in Peru. In fact it is thought that the chilli remains found in the Guitarrero caves 10,000 years ago was a pubescens type. Historically significant as the chilli in question was found alongside evidence of campfires, grinding stones and human bones. It seems chillies were considered pretty valuable food stuffs. Not much has changed in 10,000 years then.

At The Birdhouse, we only grew one plant of this type last year: the high shine red Alberto Rocoto Locato. Gifted to us by my mother. It was easy to spot in the greenhouse as the plant grew differently to the others. For one, it had tiny white hairs on its leaves. Secondly, once it had got going, it split into two branches about 30cm up. It then sprawled out sideways and needed support from other plants. It snapped easily if knocked. It had bright violet flowers, with dusty white stamen. The chillies were late to set and took a long time to ripen to glossy red, maybe a 100 days or more. It matured about sometime similar to the Scotch Bonnets and they supposedly take 120 days. The plant was prolific despite being in a smallish 2.5 L pot. Whilst it was fed well it could probably have done with more root space.

Striking purple flowers

A quick bit of research tells us that these chillies are a fan of cooler nights, although still happy basking during the day. They are far more tolerant to lower temperatures generally. Although not frost tolerant. This bodes well for a UK climate and the need for a longish growing season. They are also long lived perennials, living up to 15 years. They can be climbers or tree formations. I think we might have a few Winter inmates this year. Let the pubescens journey begin.

A Bird’s Eye (chilli) view of the Columbian Exchange.

Just how far have modern chillies come?

Everyone seems agreed that a passion for eating chillies originated in the heart of South America. Mexico initially but the news spread like wildfire, notably to the Bolivians (gatherers of wild chillies) and the Peruvians (the great chilli domesticators). Evidence of human chilli consumption can be traced back to 7,500 BC. Cultivation of chillies as a crop has been verified up to 6,000 years ago. That is a serious amount of history right there.

After thousands of years of South Americans quietly consuming, gently taming and trading chillies, how did their hot secret get out?

Let us discuss that oft mentioned historical phenomenon: The Columbian Exchange: a two way process named after Christopher Columbus, Italian explorer extraordinaire.

Previously Europe had traded with China and India via well established land routes. Silk, spices and opiates were all very much part of the European highlife. However, as politics changed and the Turkish Ottoman Empire came into power, land travel to Asia became arduous, unpredictable and dangerous. And yet the Europeans still had a desire for the exotic goods they had become accustomed to. Black peppercorns (Piper nigrum) were one such luxury. As well as a condiment, the popular hot spice was often used as payment and referred to as ‘black gold’. Christopher Columbus saw this demand and put together a proposal to find a new route to Asia. The Spanish Catholic Monarchs, Queen Isabella of Castille and King Ferdinand of Aragon, decided to employ Columbus and fund his sea voyages.

Most people were now convinced the world was a sphere. Columbus thought one could set off from Spain, sail west, across what was then called Ocean Sea and approach the other side of Asia from this new direction. Although he was a bit off in his calculations (mostly because he underestimated the size of the earth) he still managed to find land and come back with goods that impressed the Spanish court.

He first landed in the Americas in 1492. He thought he was in India and so called the islands ‘The Indies’. He succeeded in bringing back a wealth of new ideas, foods, slaves and indulgences like tobacco. He did not find the desired peppercorns but on his second trip he stumbled across local ‘aji’ hot peppers.

Unfortunately, in addition, Columbus and his crew had transferred devastating diseases like measles to the New World. It is estimated that the population of some islands was reduced by 90% as a direct result of contact with Columbus and his crew. In return, his crew contracted a number of previously unknown diseases and transported them around Europe. An exchange indeed.

European explorer map routes
European explorer voyage routes

But what happened to the chillies?

Ah yes, for a while the chillies were grown as ornamental and medicinal plants in monasteries in Spain and Portugal. After a while the monks noticed the heat of the pods and they began being used in cooking in place of black pepper.

Portuguese sailors were busy solving the Asian trade route situation another way. They too took to the sea but sailed south, along the West African coast and around the Cape of Good Hope to access the Asian goodies once more. They opened up new trade routes and the supply of spices resumed, albeit a little slower. Chillies were transported and traded along these routes.

Were there honestly no chillies in the Old World until Christopher Columbus’ voyages?

As a result of his voyages and the consequent global trade routes to the New World, a widespread exchange of plants, animals, diseases, humans, culture, technology and ideas between the New and Old Worlds occurred. Agriculture changed, populations were altered and an increased understanding of global geography ensued. And yes, you guessed it, chillies were unleashed on the rest of the world. Capsicum Chinense varieties can be traced back to the ‘aji’ that Columbus presented to the Spanish Royal court.

Of course there would have been individual overseas travellers who reached the Americas before Christopher Columbus. Saint Brendan and Leif Erikson to name a couple. They probably brought back a few souvenirs for the family, just like the rest of us when we travel abroad. Why not chillies?

Chillies have been noted and referenced across the world far earlier than the Columbus’ daring travels. For example, clear depictions of chillies in stone carving from thirteenth century Myanmar, South East Asia, mean there must have been some chilli present there before 1492.

So Columbus may not have been the first but he certainly did start a global trend.

Within 30 years of Columbus travelling to and from the New World, chillies had spread far and wide. The Portuguese took them wherever they went; Goa, Japan, West Africa, Thailand and mainland India. Chillies are relatively easy to grow and cultivate and so they were adopted by people wherever the conditions were good.

And so, in conclusion, whilst Christopher Columbus most certainly did not bring back the single Mother chilli from which all chillies have spawned. He was definitely a catalyst in sending chillies to every corner of the world. Not a bad legacy really.