Are oranges orange because oranges are orange

Facelift for fruits: only in Europe are oranges orange

Updated

Many oranges are not orange in their country of origin, but yellow to green. So that they can also be sold in this country, they are chemically treated.

What color is an orange? Most Swiss would consider this question a bad joke. Oranges, that is undisputed, are orange, hence their name. Just: oranges are not always orange. In tropical countries like Brazil, by far the most important country of origin in the world, oranges are usually yellow to green.

On the shelves of Swiss supermarkets, however, oranges are only available in the well-known coloring. Likewise other citrus fruits. Yellow mandarins? Green lemons? Unthinkable in Europe. That has to do with the expectations of consumers, says Sophia Jördens, food scientist at ETH Zurich. “In Europe and North America, green is an indication of immaturity,” she explains to the sda. That is why green oranges cannot be sold. There is no connection between the ripeness of a fruit and the color of its skin.

Temperature not low enough

Oranges are most likely to get their eponymous color when they are grown in regions with a mild climate, such as Italy or Spain, where more than half of the oranges sold in Switzerland come from. Even in these countries, however, the typical color is not guaranteed because the temperatures sometimes do not fall low enough, especially with early harvests.

So that the oranges get the desired color, the green fruits are treated with ethylene. This so-called “greening” is mainly carried out at the beginning of the orange season in southern Europe, as Marc Wermelinger, managing director of the Swisscofel fruit and vegetable traders' association, says. “During this time, the nights are still too warm and the skin is not yet completely colored. As soon as the nights get cooler, de-greening is no longer necessary. Wermelinger estimates the proportion of greened fruits in total orange sales to be “significantly less than ten percent”.

On request, Coop makes the same estimate with regard to its own citrus fruit range. In the case of Naturaplan fruit, the retailer does not use greening because it is prohibited under Bio Suisse guidelines, as Coop spokesman Ramon Gander explains.

Migros does not provide any information on how many fruits are de-greened. "This varies and depends on the variety," says media spokeswoman Christine Gaillet.

The greening of citrus fruits is not without controversy. "De-greening is an unnecessary expenditure of energy," criticizes Sophia Jördens. She would like consumers to be better informed.

The German food chemist Udo Pollmer also criticizes the fact that the treatment affects the quality. "Deactivated oranges taste a little less bland, they contain less fruit acid and age faster," he says.

Marc Wermelinger contradicts this: "I cannot imagine that the de-greening changes the taste." Because ethylene is a natural substance that is also formed in the skin of the fruit.

In Switzerland, ethylene is not permitted for greening, as the Federal Office for Agriculture says on request. However, the import of fruits treated in this way is permitted. In the EU, greening is legal and even promoted. For example, a maximum of “one fifth of the entire surface of the fruit” may be green for it to be sold.

There aren't any concerns about maturity behind this. Rather, the reason for the request is of a political nature. “The EU regulations are the work of Greece and Spain,” says Udo Pollmer. The southern European orange producers have been resisting proposals from other European countries to allow green oranges for sale for years.

Because on the one hand the fruits in Spain, Italy or Greece tend to be orange. On the other hand, they already have the necessary greening systems - in contrast to the competition from other countries. "These would have to offer their fruits to the Spaniards for de-greening," says Pollmer.

(fee / sda)