What heats the chilli: Swetha Sivakumar faces the fiery squad

Whichever way one spells it — chilli, chili or chile (India, US and Mexico, respectively) — it is definitely not a pepper, though that is how the rather error-prone Christopher Columbus mislabelled it.

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Columbus tasted the heat of chillies on the island of Hispaniola, where locals called them “aji”, and wrote in his ship’s log that he had found a pepper more valuable than black pepper. Which was a rather convenient leap, given that he had been paid by Spain’s King Ferdinand to find a new route to India’s spices, black pepper being chief among them.

Columbus’s tag persists, incidentally. The term chilli pepper is still used for this berry in parts of the Western world. Even pepper spray is, in that sense, misnamed, since its active ingredient is capsaicin from chillies, not piperine from black pepper.

The chilli plant originally evolved to produce capsaicinoids as a defence mechanism against pests, including humans. Capsaicin, the most prevalent capsaicinoid, sits in vacuoles in the placenta that houses the seeds. (The seeds by themselves are not pungent. When a chilli is cut or processed, the oils from the placenta spill onto them, making them seem so.)

Now, when consumed, capsaicin doesn’t act on the taste buds. It binds to a receptor in the mouth called TRPV1, which exists to warn us if something is too physically hot. These receptors, while more prevalent on the tongue, are also on our skin, in our eyes, in the lining of our guts. Which is why one “feels the burn” long after one has eaten a pungent meal, and why it hurts so much if one touches one’s eyes after chopping a chilli.

So why do we eat these berries? Well, they’re packed with vitamins, boost metabolism, and have antioxidant, anti-inflammatory and anticarcinogenic properties. They lend an earthy flavour and delicious bite to any meal. And they serve as an effective preservative.

Capsaicin is a rather brilliant molecule. It fights the invasion of most fungi, preventing them from proliferating. This means that chillies can retain their flavour, colour and texture through long periods of fermentation, and help preserve other foods. (There are a few strains of lactic acid bacteria that can break down capsaicin, such as Lactobacillus sakei, and these are used to create those wonderful fermented-chilli notes in dishes such as kimchi.)

Modern medicine is looking to capitalise on capsaicin as well. Researchers want to use its anti-fungal properties to fight persistent fungal infections such as Candida. Since capsaicinoids can desensitise and numb nerve cells, some are also being researched for use in managing chronic, neuropathic and osteoarthritic pain.

The higher the pungency levels, the more the capsaicin, which is why researchers are constantly cross-breeding chillies. Dramatic advances in this regard have been made in recent years. Pungency is measured on the Scoville scale, in Scoville heat units or SHU (named for American pharmacologist Wilbur Scoville, who devised the scale in 1912).

The current hottest pepper in the world, according to the Guinness Book of World Records, is the Carolina Reaper, with a rating of 2.2 million SHU. For perspective, the one-time hottest chilli, Bhut Jolokia, has a rating of about 1 million. It is a natural hybrid of two species and has been used in North-East-Indian cuisine for centuries. The Carolina Reaper was developed in 2012, by American breeder Ed Currie, using the La Soufrière (a type of Habanero from the Caribbean) and the Naga Viper from Pakistan (which has a rating of about 1.3 million SHU and was itself once tagged the hottest in the world).

Chillies like these can only add heat to food. Cross about 1 million on the Scoville scale, and the pungency is no longer perceptible as a flavour. The chillies that offer the earthiest, heartiest flavours, tend to have ratings in the thousands, like the Kashmiri chilli (about 1,500 SHU), the Byadgi (15,000 SHU) and the Guntur (about 25,000 SHU).

But these aren’t for everyone either, so cross-breeding has been used to alter chillies in the other direction too. Hungarians have, for centuries, bred gentler ones to make their famous chilli powder: paprika. The pimento chilli usually used in this condiment has a rating of about 250 SHU. One can use tablespoons of the stuff, turn a dish red with it, and still get mainly the earthy flavour, with very little heat.

My personal favourite is the Guntur, which is grown widely in Andhra Pradesh. But I love the fresh aroma of all chillies being roasted and ground. I love the flavour these berries lend to a sambar powder or milagai podi. It’s a bite so distinct, it’s hard to believe anyone mistook it for piperine.

(To reach Swetha Sivakumar with questions or feedback, email upgrademyfood@gmail.com)