Orange, Citrus x sinensis L.

The orange is the most commonly grown citrus fruit in the world and has been cultivated in South East Asia for over 7000 years. The bright hue of its fruit even gave the colour its name. The orange originated from a cross between the mandarin and the grapefruit and belongs to the citrus genus. The same parent species also gave rise to the seville (bitter) orange, which is distinguished from the orange because of its completely different taste.

Oranges – not always orange!

Orange trees are small to medium-sized evergreen trees with a round crown. Leathery leaves and thin, blunt thorns grow on the branches. Orange trees develop white, fragrant flowers and bear fruit even without cross-pollination. The fruit only develops its typical orange color through cold nights. In tropical regions, the orange remains green on the outside even during ripening. Because many consumers think green oranges are unripe, green fruit is often de-greened with ethylene gas before being sold. Although this results in a loss of quality, orange oranges are easier to market. The oil glands in the skin of the ripe orange exude an aromatic fragrance. The inner peel is white and fused with the ten to thirteen fruit segments inside the orange. This makes the orange more difficult to peel or divide than other citrus fruits.

There are four groups of sweet oranges: The white (common) oranges have a round fruit shape and form the most important group. The navel oranges (also known as Bahia oranges) come from Brazil and are characterised by a protrusion at the flowering bud. Juice can be easily extracted from them. The group of pigmented oranges includes blood oranges and half-blood oranges and are characterized by their flesh coloured in various shades of red. The group of acid-free oranges are native to India and have a green or yellow skin. They are low in acidity and have a sweet taste.

Orange country Brazil

Today, Brazil is by far the world’s largest producer of oranges. Oranges or orange juice can be found in almost every household in Brazil and almost 30 percent of Brazil’s orange production is consumed domestically. The rest is mainly exported to North America and Europe in the form of orange juice concentrate.

The orange was introduced to Brazil at the beginning of colonisation. In the fertile soil and under the warm Brazilian sun, it found ideal conditions to take root. Around the year 1800, a special orange variety developed in the city of Salvador da Bahia, which became known as the Bahia orange and made orange production a solid part of Brazilian agriculture. The Brazilian orange then became an export product at the end of the 19th century: the American Civil War led to a considerable drop in North American orange production. This shortage on the North American markets gave Brazil the opportunity to export not only fresh oranges, but also orange juice. As a result, small factories were gradually established in the interior of the state of São Paulo, which produced orange juice, expanded over the years and have been able to maintain their position on the global market to this day. Brazil is followed by India, China and Mexico as other important orange producers. In total, over 140 countries produce citrus fruit. The largest importer of orange juice and concentrate is the USA. The Netherlands, on the other hand, imports the most fresh oranges.

Healthy lifesaver

Many people know that oranges are rich in vitamin C and therefore strengthen the immune system. Many seafarers used to take citrus fruits, especially oranges, on board to combat scurvy. This is how the orange became a lifesaver back then.

But oranges also contain many other healthy substances: for example, a good dose of magnesium and some calcium. These two minerals help to maintain strong bones and teeth. Studies have also shown that regular consumption of oranges can help to lower blood pressure. The potassium in oranges is probably responsible for this. The white skin that covers the orange slices is very healthy and should definitely be eaten: It contains secondary plant substances that can reduce the risk of cardiovascular disease and fiber, which contributes to good digestion. Regular consumption of oranges can also lower cholesterol levels and facilitate the absorption of iron in the body thanks to the high vitamin C content. A study conducted by the University of Hohenheim in 2015 concluded that people can absorb certain ingredients such as vitamin C better when drinking orange juice than when eating an unprocessed orange. However, it is important to make sure that the juice has no added sugar. Orange juice should also only be drunk in moderation because it contains a lot of natural fructose in addition to the healthy ingredients.

In addition to the pulp, the peel of oranges is also used on a much smaller scale. They are used to extract fine fragrances that are used in various forms in the perfume industry. Wafer-thin zests made from orange peel can be used to flavor food and both dried orange peel and orange blossom can be added to tea blends.

Disease threatens orange production

The large orange-growing regions in Florida and Brazil are threatened by a disease: citrus greening disease is caused by bacteria that are transmitted by leaf fleas. If a citrus plant is infected with the disease, it can no longer transport its nutrients properly. The fruit remains small and does not ripen, but remains bland and dry. In Florida, only half as many oranges could be harvested in 2016 as in 2009 due to the citrus greening disease and there are fears that the disease will spread to other orange-growing regions in the future. Attempts to breed resistant orange varieties have so far been unsuccessful. Large quantities of insecticides are sprayed to combat the leaf fleas, but a good supply of nutrients and the rapid systematic cutting down of infested trees also help to contain the disease. The effort is large and expensive. As a result, many small farms have to fight for their existence or even cease operations.

Sources

AFZAL, Uroosha; PAUL, Virginia. CRITICAL REVIEW ON THERAPEUTIC VALUE OF ORANGES (CITRUS SINENSIS). 2023.
ETEBU, E.; NWAUZOMA, A. B. A review on sweet orange (Citrus sinensis L Osbeck): health, diseases and management. American Journal of Research Communication, 2014, 2.2: 33-70.
Dictionary of the Agricultural Area: Orange. Link.
Encyclopedia of plants: Orange. Link.
Feitoza & Gasparotto (2020): A study on national production of concentrated orange juice. Link.