Radish

Radish is a crunchy root vegetable grown in many countries and can be available almost year-round. However, exact availability depends on which variety you are looking for and in which region you live. Generally: radish prefers cooler weather. That is why it is often harvested in spring and autumn. Some varieties are bred to grow well in summer or even winter. In supermarkets you will often find radish throughout the year, because it is harvested at different times in different countries and imported.

The origin of radish is historically rooted in Asia, especially China and Japan. From there it spread over the centuries to Europe and other parts of the world. Today some of the radish in Europe comes from countries such as Germany, the Netherlands, France and Italy. In Asia, China, Korea and Japan are important growing regions. Many farmers’ markets offer regional radishes that are freshly harvested depending on the season. In winter there is often the large white daikon (also called winter radish), while in summer smaller, firmer varieties are more common.

Radish is not all the same. There are many varieties and types that differ in color, shape, size, pungency and flavor. Some are mild and juicy, others very flavorful and sharp. To give you a good overview, here are the main types:

Radish (Raphanus sativus var. longipinnatus and var. niger) is a cultivated form of the genus Raphanus within the family Brassicaceae (mustards). The edible storage root is characterized by a high content of sulfur-containing glucosinolates, a pronounced primary root morphology and distinctive sensory properties. Depending on the variety, color differences from white through pinkish to black occur; texture ranges from crunchy and juicy to firm and pungent. From a nutritional perspective radish is low in energy but contains relevant amounts of vitamin C, potassium and bioactive secondary plant compounds.

Botany and morphology
The plant forms a thickened taproot that serves as a storage organ for water and reserves. The root parenchyma is rich in watery tissue whose cells carry the characteristic aromas. The foliage is coarsely lobed, pubescent and arranged in a rosette. Flowers appear in racemose inflorescences, are four-parted and typical for brassicas. Variety-typical differences occur in shape (cylindrical to conical), length and surface texture of the root. Black radish shows a corky, dark periderm layer with increased storability, while white radish (e.g. daikon) has a smooth epidermis and milder flavor profiles.

Origin and breeding
Archaeobotanical and historical sources place domestication in West Asia to the eastern Mediterranean, with later diversification in East Asia. Asian types (daikon) were selected for milder taste, fast growth and large root masses; European types (summer, winter, beer and black radish) for pungency, skin color and storage ability. Modern cultivars arise through classical selection, hybrid breeding and marker-assisted methods, taking into account disease resistances, bolting tendency and adaptation to photoperiod and temperature.

Constituents and chemical characteristics
Radish is rich in glucosinolates (e.g. glucoraphenin, gluconasturtiin