Avocado

Avocados are now found in supermarkets almost everywhere, but they originally come from Central America. Countries such as Mexico, Guatemala and parts of South America play a particularly important role. Later avocado trees were also planted in warm-climate regions, for example in California and Florida in the USA, in Israel, in Spain (especially Andalusia and the Canary Islands), Morocco, Chile and Peru. Because harvests in these countries occur at different times, avocados are relatively available year-round. Still, supply fluctuates somewhat depending on season, weather and transport routes.

Avocados grow on trees and need a mild, frost-free climate. There are three main origin groups, also called "races": Mexican, Guatemalan and West Indian. These groups differ in taste, skin, size and cold tolerance. Many of the avocados we eat are hybrids, i.e. mixes of these groups. This allows breeders to develop varieties that taste particularly good, have a good shape and transport well.

Why aren't avocados always ripe in the store?
Avocados are usually picked when they are ripe enough but still firm. They then continue to ripen after picking. This is practical because it allows them to withstand long transport. At home you can speed up ripening by placing the fruit next to apples or bananas. These release a gas called ethylene, which makes the avocado soften more quickly.

The avocado, scientifically Persea americana, is an evergreen fruit of the laurel family (Lauraceae) and is botanically classified as a berry with a single large seed. Originally domesticated in Mesoamerica, it is now cultivated in tropical and subtropical zones worldwide. The fruit is characterized by an exceptionally high fat content, a creamy matrix and a complex composition of bioactive compounds. Its sensory quality, nutritional relevance and technological versatility make it an important raw material in the food industry, gastronomy and cosmetics.

Botany and morphology
Avocado trees reach 10–20 m in height, have leathery evergreen leaves and unisexual flowers with protogynous dichogamy behavior, which promotes cross-pollination. Cultivars are categorized into the "Mexican", "Guatemalan" and "West Indian" races, which differ in skin structure, oil and dry matter content, cold resistance and harvest windows. The fruit is pyriform to ovoid; skin ranges from smooth to rough (e.g. cultivar 'Hass') and depending on pigmentation from dark green to purple-black at full ripeness. The flesh shows a light green to yellowish chromaticity with low pigmentation and high lipid accumulation.

Ripening and postharvest physiology
Avocados are climacteric fruits: after harvest ethylene production increases, accompanied by a respiratory peak. The subsequent activity of cell wall–modifying enzymes (polygalacturonase, pectin methylesterase) leads to texture softening. Storage temperatures of 4–7 °C (depending on cultivar) slow ripening, while controlled atmospheres (e.g. 3–5% O2, 3–10% CO2) reduce senescence. Cold sensitivity manifests as browning and water accumulation in the flesh. For synchronized ripening exogenous ethylene (100–150 ppm, 18–24 °C) is often applied.