Why do citrus fruits taste sour

Mandarins and clementinesSweet, angry, woody or leathery

The common tangerine is actually not a tangerine at all, but a clementine. At least biologically. And otherwise it is also good for surprises. Often sweet, sometimes sour, but why?

DRadio knowledge reporter Almuth Knigge was at the weekly market and bought tangerines. Rather, she thought she had bought tangerines, and it was clementines. Almuth is informed about this by Uwe Nehls, who is a botanist at the University of Bremen and knows the differences exactly.

He did some research on the ancestry of the clementines, but even there the relationships among the various citrus fruits are complicated and in some cases not yet clearly clarified.

"There is certainly a grapefruit in the tangerine. It has long been assumed that the second parent is bitter oranges. Today, people actually believe that it is not bitter oranges, but sweet oranges."
Uwe Nehls, botanist at the University of Bremen

Whether a clementine is more sour or sweeter is sometimes related to whether it was hanging on the tree inside or outside and thus received more shade or more sun. Sometimes it just has to do with the fact that it is a different variety or that it was picked earlier.

Freshness indicator:

  • Skin that is shiny and is relatively tight - but if the skin is too tight and difficult to peel, it can also mean that the fruit was not quite ripe when it was picked.

Indicator of drought:

  • The skin is loose - this fruit has probably been stored too long and too warm and has lost moisture.

Indicator for harmless fruit:

  • In general, organic fruits are healthier because they have not been treated with preservatives. You should wash fruits that have been sprayed with chemicals before peeling them. Not only the fruit, but also the hands should be clean, as the preservatives can stick to the skin.

Healthy fruit indicator:

The white fibers between the pulp and the skin are considered healthy by nutritionists. They contain the substance limonene and the secondary plant substances flavanoids. It is believed that these substances have a preventive effect on certain diseases. The white fibers are bred out because consumers don't like them. If you can find them on the fruit, you don't have to remove them completely.

Proper storage is important

So that the fruits don't taste woody or leathery too quickly, it is important to store them correctly. They should be stored in a place that is cool, has plenty of humidity, and has enough space. If the fruits are on top of each other, they quickly develop pressure points, which can then become moldy. When the temperature is not below zero, you can keep the citrus fruits on the balcony, put them in a cool pantry or store them in the basement.