A Nut is a hard-shelled fruit of some plants having an indehiscent seed. While a wide variety of dried seeds and fruits are called nuts in English, only a certain number of them are considered by biologists to be true nuts. Any large, oily kernel found within a shell and used in food may be regarded as a nut.
Because nuts generally have a high oil content, they are a highly prized food and energy source. A large number of seeds are edible by humans and used in cooking, eaten raw, sprouted, or roasted as a snack food, or pressed for oil that is used in cookery and cosmetics. Nuts used for food, whether true nut or not, are among the most common food allergens.
Some fruits and seeds that do not meet the botanical definition but are nuts in the culinary sense:
- Almonds, pecans and walnuts are the edible seeds of drupe fruits — the leathery "flesh" is removed at harvest.
- Brazil nut is the seed from a capsule.
- Candlenut (used for oil) is a seed.
- Cashew nut is a seed.
- Horse-chestnut is an inedible capsule.
- Macadamia nut is a creamy white kernel (Macadamia integrifolia).
- Malabar chestnut
- Peanut is a legume.
- Pine nut is the seed of several species of pine (coniferous trees).
- Pistachio nut is the seed of a thin-shelled drupe.