Avocado or alligator pear also refers to the fruit, a large berry that contains a large seed, of the tree, which may be pear-shaped, egg-shaped or spherical.
Avocados are a commercially valuable fruit and are cultivated in tropical climates throughout the world, producing a green-skinned, pear-shaped fruit that ripens after harvesting.
Trees are partially self-pollinating and often are propagated through grafting to maintain a predictable quality and quantity of the fruit.
The tree grows to 20 m, with alternately arranged leaves 12 centimetres – 25 centimetres long.
The flowers are inconspicuous, greenish-yellow, 5 millimetres – 10 millimetres wide. The pear-shaped fruit is 7 centimetres – 20 centimetres long, weighs between 100 grams – 1,000 grams (35 oz), and has a large central seed, 5 centimetres – 6.4 centimetres long.
The subtropical species needs a climate without frost and with little wind.
High winds reduce the humidity, dehydrate the flowers, and affect pollination.
When even a mild frost occurs, premature fruit drop may occur, although the Hass cultivar can tolerate temperatures down to −1°C.
The trees also need well-aerated soils, ideally more than 1 m deep.
Avocados are high in valuable, health-promoting fats.
For a typical avocado:
About 75% of an avocado's calories come from fat, most of which is monounsaturated fat.
Avocados also have 60% more potassium than bananas.
They are rich in B vitamins, as well as vitamin E and vitamin K.
Avocados have a high fiber content among fruits – including 75% insoluble and 25% soluble fiber.
A fatty triol with one double bond, avocadene (16-heptadecene-1,2,4-triol), is found in avocado.
High avocado intake has been shown to have a beneficial effect on blood serum cholesterol levels.
Specifically, after a seven-day diet rich in avocados, mild hypercholesterolemia patients showed a 17% decrease in total serum cholesterol levels.
These subjects also showed a 22% decrease in both LDL (harmful cholesterol) and triglyceride levels and 11% increase in HDL (helpful cholesterol) levels.
Additionally a Japanese team synthesised the four chiral components, and identified (2R, 4R)-16-heptadecene-1, 2, 4-triol as a natural antibacterial component.