Avocado

Avocado (Persea americana) is a tree and the fruit of that tree, classified in the flowering plant family, Lauraceae. It is native to Central America and Mexico. The tree grows to 20 m (65 ft), with alternately arranged, evergreen leaves, 12-25 cm long. The flowers are inconspicuous, greenish-yellow, 5-10 mm wide. The pear-shaped fruit is botanically a berry, from 7 to 20 cm long, and weighs between 100-1000 g. It has a large central seed, 3-5 cm in diameter. An average avocado tree produces about 120 avocados annually. The fruit is sometimes called an avocado pear or alligator pear, from its shape and green skin. The avocado tree does not tolerate freezing temperatures, and so can be grown only in subtropical and tropical climates.

Barlow & Martin (2002) identify the avocado as a fruit adapted for ecological relationship with large mammals, now extinct (as for example the South American herbivorous giant ground sloths or Gomphotheres). This fruit with its mildly toxic pit, co-evolved with those extinct mammals to be swallowed whole and excreted in dung, ready to sprout. The ecological partners have disappeared, and the avocado plant has not had time to evolve an alternative seed dispersal technique.

The fruit of horticultural cultivars range from more or less round to egg or pear-shaped, typically the size of a temperate zone pear or larger, on the outside bright green to green-brown (or almost black) in color, and high in fat. Though the fruit does have a markedly higher fat content than most other fruit, most of the fat in avocados is monounsaturated fat, which is considered healthy in the human diet. A whole medium Avocado contains approximately 25% of the Daily Value of saturated fat. Avocados also have 60% more potassium than bananas.

The flesh is typically greenish yellow to golden yellow when ripe. The flesh oxidizes and turns brown quickly after exposure to air. To prevent this, a highly acidic juice like lime or lemon juice can be added to avocados after they are peeled. The avocado is very popular in vegetarian cuisine, making a good substitute for meats and cheeses in sandwiches and salads because of the high fat and protein content. The fruit is not sweet, but fatty, flavorful, and of smooth, almost creamy texture. It is used as the base for the Mexican dip known as guacamole, as well as a filling for several kinds of sushi, including California rolls. In Brazil, avocados are added to ice cream and in the Philippines, a dessert drink is made with sugar, milk, and pureed avocado.