The bitter orange (Citrus x Aurantium), also called bitter orange, belongs to the rue family (Rutaceae). The fruit grows on an evergreen tree native to Asia. However, it is now also grown in the Mediterranean region.

As its name suggests, the fruits of the bitter orange taste sour and bitter, unlike the sweet orange. They are also smaller and darker. Their skin is thicker and their pulp contains more seeds.

Bitter orange can be used in different ways. As a component of perfumes, it has been used for many years. In food, bitter oranges are used, for example, for the production of various liqueurs and jams. In nutritional supplements, the fruit is interesting due to apigenin and naringin.