5 Pepper Facts That Bring the Heat

Chili Peppers Have More Vitamin C Than Oranges

Oranges have a reputation for being rich in vitamin C, and for good reason, as a typical orange provides roughly 95.8 milligrams of the vitamin per cup, which is roughly equivalent in size to one medium-to-large orange. But chili peppers are far more potent, offering 364 milligrams of vitamin C per cup (picture three medium-sized raw red chili peppers), or roughly four times as much as oranges. 

Part of the reason hot peppers have so much vitamin C is it’s essential to their growth, serving as a natural antioxidant that protects the fruit against environmental stressors. But people still associate oranges, rather than peppers, much more closely with vitamin C largely due to the success of early 20th-century marketing campaigns to sell orange juice based on its vitamin content. Furthermore, many early studies about vitamin C honed in on oranges as a viable source, while overlooking other fruits such as peppers.

But it’s not just vitamin C that makes chili peppers nutritionally beneficial, as they’re also loaded with other essential vitamins. Those include B6, which is essential for metabolism function, and K1, which helps promote healthy bones and kidneys. 

Pepper X Is Considered the World’s Hottest Pepper

Since 2023, a chili pepper cultivar known as Pepper X has been heralded as the world’s hottest pepper. This is according to the Scoville scale, a tool created in 1912 by pharmacologist Wilbur Scoville to quantify the heat levels for each variety of pepper. 

Pepper X tops the scale at 2.693 million Scoville Heat Units (SHUs), or the number of times concentrated capsaicinoids need to be diluted before heat is no longer detectable. This makes Pepper X hundreds of times spicier than the average jalapeño, which falls between 2,000 to 8,000 SHUs.

Pepper X was cultivated by American chili pepper breeder Ed Currie, who also previously created the Carolina Reaper — a pepper that held the top Scoville ranking from 2013 to 2023 at 1,641,000 SHUs. When developing Pepper X, Currie crossbred a Carolina Reaper with a mystery pepper, resulting in the record-breaking cultivar. 

While Currie has yet to make Pepper X seeds publicly available, he described his own experience consuming the pepper in an interview with Scientific American. Currie said the pepper is delicious in hot sauce and salsa, but he “wouldn’t recommend eating it raw to anybody,” adding that it took him five to six hours to recover from the ensuing stomach cramps.

A Pepper’s Heat Only Affects Mammals

While a human would have a tough time handling the heat from a raw Pepper X, a parrot or iguana could scarf one down with ease, because the burn from capsaicin only affects humans and other mammals. Birds, reptiles, and amphibians lack the pain receptors (known as TRPV1) found in mammals that respond to spicy foods. 

In fact, not only are birds immune to the heat, but they also play an essential role in helping hot peppers grow. Birds are known to eat peppers and their seeds, fly to a different location, and then disperse the seeds in their droppings, helping spread the crop.

But turning our attention back to mammals, there is one fascinating exception to the rule: tree shrews. Unlike other mammals, these tiny critters can eat hot peppers without feeling the intense heat. This is due to a genetic mutation of the TRPV1 pain receptors, which prevents heat from binding to those pain receptors like it does in other mammals.

Only Five Species Produce Thousands of Pepper Varieties

Though estimates differ, there are around 26 wild species of Capsicum — the genus of flowering plants from which peppers grow. But there are only five major domesticated species of the plant, which provide us with the thousands of pepper varieties we regularly enjoy. Those five species are Capsicum annuum, C. chinense, C. frutescens, C. pubescens, and C. baccatum, all of which originated in various parts of South and Central America.

Capsicum annuum produces varieties such as jalapeños, poblanos, and cayenne. C. chinense gives us habaneros, scotch bonnets, and ghost peppers, while C. frutescens provides the tabasco pepper variety. Under the C. pubescens umbrella you’ll find rocoto, manzano, and locoto peppers, while C. baccatum features varieties such as the citrus-flavored Lemon Drop pepper and the spicy, bright-orange aji amarillo pepper.

The Seeds Aren’t the Spiciest Part

An oft-repeated misconception is that the seeds are the spiciest part of any chili pepper. That’s not to say the seeds don’t hold heat — they do — but the highest concentration of capsaicin is actually contained within the pepper’s placental tissue. When you slice open a pepper, that tissue is the white internal membrane seen inside, and it’s called the pith.

Using jalapeño peppers as an example, their pith contains 512 milligrams of capsaicin per kilogram. That’s roughly seven times spicier than the seeds (73 mg/kg) and more than 100 times spicier than the flesh (just 5 mg/kg). While the precise numbers vary from pepper to pepper, the pith is consistently the hottest component.