An aril is a fleshy covering that grows around certain seeds, formed from the point where the seed attaches to its parent plant. If you’ve ever eaten a pomegranate, you’ve eaten arils: those jewel-like, juice-filled sacs surrounding each tiny seed. But pomegranates are just one example. Arils appear across hundreds of plant species and serve purposes ranging from feeding wildlife to flavoring your spice rack.
How Arils Form and Why They Exist
Every seed connects to its parent fruit through a small stalk called a funiculus. The aril develops from an expansion of this attachment point (or the scar it leaves, called the hilum), growing outward to partially or fully envelop the seed in soft, nutrient-rich tissue. This structure appears in both ancient seed-bearing plants like conifers and in flowering plants, suggesting it evolved independently multiple times because it works so well.
The biological purpose is straightforward: arils bribe animals into spreading seeds. The fleshy tissue accumulates sugars, oils, and aromatic compounds that attract birds, mammals, and other fruit-eating animals. An animal eats the nutritious aril, moves on, and deposits the seed somewhere new. The aril essentially functions like a fruit for plants that don’t produce true fleshy fruits, making it directly tied to a species’ reproductive success in the wild. This strategy is especially common in tropical and subtropical plants, where competition for seed dispersers is fierce.
Common Edible Arils
Several foods you likely recognize are arils or contain them, though they’re rarely labeled that way at the grocery store.
Pomegranate is the most familiar example. Each pomegranate contains hundreds of seeds, and each seed is wrapped in a translucent, ruby-colored aril filled with juice. A whole raw pomegranate (roughly 100 grams of arils) provides about 83 calories, 4 grams of fiber, and meaningful amounts of vitamin C and vitamin K. The juice contains pigments called anthocyanins, which give pomegranate its deep red color and contribute to its antioxidant properties. A meta-analysis of clinical trials found that regular pomegranate consumption was associated with a reduction in systolic blood pressure of about 7.9 mmHg and diastolic pressure of about 3.2 mmHg, with the strongest effects in people who already had elevated blood pressure above 130 mmHg.
Durian, the famously pungent Southeast Asian fruit, has thick, creamy arils surrounding its large seeds. Unlike most arils, durian’s are unusually high in fat, ranging from about 1.6 to 5.4 grams per 100 grams of fresh fruit. That gives durian a caloric density of 84 to 185 calories per 100 grams, considerably higher than most fresh fruits.
Passion fruit contains arils that are packed with sugars and aromatic compounds, giving the fruit its intensely fragrant, tangy flavor. Lychee and its relatives longan and rambutan also feature translucent, sweet arils as the edible portion surrounding a single large seed.
Arils as Spices
Not all arils are eaten fresh. The spice mace comes from the aril of the nutmeg tree. When a ripe nutmeg fruit splits open, it reveals a dark seed (the nutmeg itself) wrapped in a bright crimson, web-like aril. This aril is carefully peeled away, flattened, and dried for 10 to 14 days, during which its color fades to pale yellow, orange, or tan. The result is mace, a spice with a flavor similar to nutmeg but lighter and more delicate. So nutmeg and mace come from the same fruit: one is the seed, the other is the aril.
Castor beans offer another example, though not a culinary one. Their arils are rich in oils, and the plant has long been cultivated for industrial and pharmaceutical uses.
When Arils Are Safe (and When They’re Not)
The yew tree provides a striking lesson in the difference between an aril and the seed it surrounds. Nearly every part of the yew, including its needles, bark, and seeds, contains toxic compounds called taxines that can be lethal to humans and animals. The one exception is the bright red, berry-like aril that encases each seed. The aril itself is sweet and nontoxic, and birds eat them readily, digesting the fleshy covering and passing the poisonous seed unharmed. This is a case where the plant’s dispersal strategy hinges on the aril being safe to eat while the seed remains dangerous.
For commercially sold arils like pomegranate, the seeds inside are also safe to eat. Most people swallow the small, crunchy seeds along with the juice sac without any issue. The seeds add fiber and a mild crunch but are otherwise nutritionally modest compared to the juice-filled aril surrounding them.
Storing and Using Pomegranate Arils
Because pomegranate is the aril most commonly sold on its own, knowing how to handle it matters. Whole pomegranates keep for weeks at room temperature, but once you extract the arils (or buy them pre-packaged), the clock starts ticking. Stored at around 41°F (5°C) in the refrigerator, extracted arils typically last 7 to 21 days depending on the variety and how fresh they were at the start. Signs of spoilage include visible mold, off smells, and a slimy texture on the arils’ surface.
Fresh arils work well scattered over salads, yogurt, and grain bowls, where their burst of tart juice adds both flavor and color. They also blend easily into smoothies or can be pressed for fresh juice. Freezing extends their life considerably: spread arils in a single layer on a baking sheet, freeze until solid, then transfer to an airtight bag. Frozen arils hold up for several months and thaw quickly.
Aril vs. Fruit: The Distinction
It’s easy to confuse arils with fruits, since both are fleshy plant tissues designed to attract animals. The key difference is origin. A true fruit develops from the ovary of a flower after fertilization. An aril develops from the seed’s attachment point after the seed has already formed. In some plants, like pomegranate, arils exist inside a fruit, so you’re dealing with both structures at once. In others, like yew, there is no true fruit at all, and the aril is the only fleshy tissue present.
This distinction matters more to botanists than to cooks, but it explains why “pomegranate arils” and “pomegranate seeds” are used interchangeably in recipes. Technically, the seed is the hard bit in the center. The aril is everything around it. When someone says they’re eating pomegranate seeds, they’re really eating the arils with the seeds along for the ride.