Cayenne

Capsicum annuum

Family: Solanaceae Part used: Fruit (dried and ground)

Key Compounds

• Capsaicin
• Dihydrocapsaicin
• Nordihydrocapsaicin
• Capsanthin
• Capsorubin
• Quercetin
• Luteolin
• Vitamin C

Traditional Use

• Pre-Columbian use throughout the Americas — documented from Mexico to Peru across multiple civilisations
• Post-1493 global adoption — Portuguese and Spanish traders spread Capsicum across South Asia, East Asia, Africa, and Eastern Europe within 50 years of Columbus
• Indian Ayurvedic and folk medicine — from roughly the 16th century onward (post-Columbian arrival)
• Traditional Chinese and Korean medicine — incorporated after 16th century adoption
• Japanese cooking — shichimi togarashi, rayu, yuzu kosho; integral since the late 1500s
• Commercial capsaicin preparations — topical pain applications; also pepper spray (OC spray)

The burning sensation from capsaicin is not damage. It is your brain being told it is hot when it is not.

The receptor that capsaicin activates — TRPV1 — is your body’s heat detector. It normally fires when temperature exceeds approximately 43°C. Capsaicin binds to it and triggers the same signal without any temperature change. Your mouth reports that something is burning. Nothing is burning. The burning is accurate, in the sense that your heat detector is correctly reporting that it has been activated. It is inaccurate in the sense that there is no heat. The chili pepper has been telling mammal nervous systems this lie for millions of years, and it keeps working.

Meet the plant

Capsicum annuum covers more ground than its name suggests. Bell peppers, jalapeños, cayenne peppers, serranos, paprika — all Capsicum annuum. Same species, different cultivars. The enormous variation in heat level (near zero for bell peppers, 30,000–50,000 Scoville units for cayenne-type cultivars) comes from differences in capsaicin production, not from different plant species. The bell pepper and the cayenne are the same plant. One of them decided not to make capsaicin.

Capsaicin is produced only in the genus Capsicum. No other plant makes it. It is concentrated in the placenta — the white tissue inside the fruit that holds the seeds — not in the seeds themselves, despite what most people believe about the seeds being the hot part. The seeds in a chili pepper are hot primarily because they are in contact with the placenta.

The plant grows annually in temperate climates (perennially in tropical ones), preferring warm conditions and full sun. Commercial cayenne-type peppers are grown primarily in India, Mexico, and China, then dried and ground.

500 years of everybody deciding this was theirs all along

Capsicum is native to the Americas. Archaeological evidence places its use in Mexico, Peru, and the Caribbean going back at least 6,000 years. When Columbus returned to Europe in 1493, he brought peppers, having decided they were related to black pepper (Piper nigrum). They are not — they belong to completely different plant families, and produce their heat through entirely different chemistry. The name “pepper” stuck. The confusion is still on every grocery store label.

Portuguese and Spanish traders spread Capsicum across the globe at a rate that is unusual even for post-Columbian exchanges. Within roughly 50 years, chili peppers had been adopted into Indian cooking, Korean fermentation, Thai curries, Chinese Sichuan cuisine, and Hungarian paprika. Cuisines that now feel ancient and regional were rebuilt around a plant that had arrived from the other side of the world within living memory of their grandparents. Nobody involved in this process appears to have found it remarkable.

Indian cuisine without chili peppers. Korean kimchi without heat. Thai green curry without green chilies. Hungarian goulash without paprika. These are real historical possibilities, not long ago. The version with chili peppers is the recent version. It has become the version everyone assumes is original.

The chemistry that surprised everyone

Capsaicin (8-methyl-N-vanillyl-6-nonenamide) is the primary compound. Its close relative, dihydrocapsaicin, has similar potency and is often the second-largest fraction. Together these two account for most of the heat in most peppers. Nordihydrocapsaicin and several minor capsaicinoids round out the full capsaicinoid profile.

The TRPV1 receptor that capsaicin activates is found in mammals and is absent from or insensitive to capsaicin in birds. This is not an accident. Birds swallow seeds intact and deposit them elsewhere; they are useful to the plant for seed dispersal. Mammals chew, which damages seeds; they are not useful to the plant for dispersal. Capsaicin is a selective deterrent — designed to be painful for the creatures that harm the plant’s seeds while invisible to the creatures that help spread them. The plant has been implementing this policy consistently for a very long time.

The other notable chemistry: capsanthin and capsorubin are the carotenoid pigments that give red peppers their colour. Vitamin C content in fresh peppers is high (mature red pepper contains more vitamin C per gram than citrus fruit). Neither of these survived the attention paid to capsaicin.

Capsaicin is fat-soluble. Water does not dissolve it — water spreads it. Dairy works because casein (a protein) binds to capsaicin and carries it away. Alcohol dissolves it. These are not folk remedies. They are correct chemistry.

What people actually do with it

Eat it: Ground cayenne in cooking — most of the world, most of the time. The most common application by volume is also the least discussed. Indian curries, Korean gochujang, Sichuan mala, rayu in Japan — all of them are just cooking with this fruit.

Shichimi togarashi (七味唐辛子): Japan’s seven-spice blend. Typically: red pepper, sansho pepper, sesame, hemp seeds, nori, yuzu peel, ginger or poppy seeds (varies by producer). A table condiment in many Japanese restaurants. Sprinkled on ramen, soba, udon, yakitori, nabe. The blend varies by region and maker — but chili pepper is always in it.

Yuzu kosho: A Kyushu specialty. Green or red chilies fermented with yuzu zest and salt. Intensely flavored, used sparingly. Served with grilled meat, nabemono, and as a condiment generally. The combination of citrus, salt, fermentation, and chili produces something that tastes different from any of its components separately.

Topical applications: Capsaicin depletes substance P — a neuropeptide involved in transmitting pain signals — from sensory nerve endings with repeated application. This is the basis of commercial capsaicin creams and patches used in pain management. The mechanism is the same one that makes your mouth stop registering heat after eating chili repeatedly: the nerve endings run out of the chemical they need to report the signal. They eventually replenish. While they don’t, the pain channel is quieter. This is current pharmacology, not traditional practice — though traditional use of chili in topical applications long predates the explanation.

Could you grow this yourself?

Yes — Capsicum annuum is one of the more manageable options for home cultivation in Japan. Warm season crop: sow indoors April–May, transplant after last frost, harvest August–October. Needs full sun and warmth; does poorly in cold, wet conditions. Container growing is practical on south-facing balconies.

Commercial cayenne-type peppers in Japan are grown in Yamagata and other warmer prefectures, but most supply is imported from India, China, and Korea. Home cultivation provides fresh peppers of whatever heat level you choose; drying and grinding them yourself takes a dehydrator or a hot dry summer.

In Japan

Chili pepper arrived in Japan in the late 16th century, via Korea or China — hence 唐辛子 (とうがらし), where 唐 refers to China (Tang dynasty), not to the plant’s American origin. The name records the arrival route, not the birthplace.

It became essential. Shichimi togarashi (七味唐辛子) is on most Japanese restaurant tables. Ichimi togarashi (一味唐辛子) — pure ground chili — is in most Japanese home kitchens. Rayu (ラー油, chili oil) is a standard condiment, with elaborate artisanal versions becoming popular in the 2010s. Yuzu kosho is available in supermarkets now, not only as a regional specialty.

Commercially produced shichimi togarashi: Yagenbori (やげんぼり, Tokyo), Shichimiya Honpo (七味家本舗, Kyoto), Yawataya Isogoro (八幡屋礒五郎, Nagano) — three of the historically significant producers with distinctly different formulas. A subject on which opinions exist.

Ground “cayenne pepper” (カイエンペッパー) as a distinct product is available at Kaldi Coffee Farm and specialty spice retailers. Amazon Japan carries multiple forms.

Things you’re probably wondering

Why doesn’t water help when your mouth is burning? Capsaicin is fat-soluble. Water spreads it. Dairy casein or alcohol dissolves it. Bread and rice absorb some of it. Cold water may help briefly via temperature, not chemistry.

Why can birds eat chili without pain? Their version of the TRPV1 receptor doesn’t respond to capsaicin. The plant evolved this specifically — birds disperse seeds intact, mammals destroy them. Capsaicin was designed for this distinction.

Did Indian and Korean food always use chili? No. Capsicum is American. It arrived in South and East Asia in the early 1500s via Portuguese and Spanish trade routes. The cuisines as they exist now are built around a post-Columbian ingredient.

What is the Scoville scale? Invented 1912 by pharmacist Wilbur Scoville using a human taste-panel dilution method. That method has been replaced by chemical analysis (HPLC). The unit name is retained. The original method is no longer used.

Where to buy chili products in Japan? Shichimi and ichimi togarashi: every supermarket. Rayu: most supermarkets. Yuzu kosho: specialty food shops, department store food halls. Ground cayenne: Kaldi Coffee Farm, specialty spice shops, Amazon Japan.

Botanical details

The full compound list

Capsaicinoids:

• Capsaicin — primary
• Dihydrocapsaicin — second largest fraction
• Nordihydrocapsaicin
• Homocapsaicin
• Homodihydrocapsaicin

Carotenoids (red colour):

• Capsanthin
• Capsorubin
• β-Carotene

Vitamins and flavonoids:

• Vitamin C (high in fresh fruit)
• Vitamin A (from carotenoids)
• Quercetin
• Luteolin

See Also

• Ginger (Zingiber officinale) — separate heat compound (gingerol/shogaol); TRPV1 also activated, different receptor site
• Black pepper (Piper nigrum) — piperine-mediated heat; the plant Columbus thought cayenne was related to
• Turmeric (Curcuma longa) — same Zingiberaceae as ginger; curcumin chemistry; often paired with chili in Indian cooking

References

• Perry L et al. “Starch fossils and the domestication and dispersal of chili peppers.” Science 2007
• Caterina MJ et al. “The capsaicin receptor: a heat-activated ion channel in the pain pathway.” Nature 1997
• Andrews J. Peppers: The Domesticated Capsicums. University of Texas Press, 1995
• Scoville WL. “Note on capsicums.” J Am Pharm Assoc. 1912
• Nunn NA. “The Columbian Exchange: A History of Disease, Food, and Ideas.” J Econ Perspect. 2010