Rhubarb

Rhubarb is an interesting plant that many people use for compote, cakes or syrup. Although it often appears fruit-like, botanically rhubarb is classified as a vegetable. Its long, juicy stalks are edible, while the large green leaves are not – they contain too many natural compounds that are unhealthy for us. To help you get to know rhubarb, let's look at where it comes from, when it's available to buy and which varieties and types exist.

Rhubarb originally comes from regions in Asia, especially Tibet and China. There it was used long ago as a medicinal plant. In the 18th and 19th centuries it came to Europe and spread quickly because it is hardy and grows well in cool climates. Today rhubarb is cultivated in many countries, for example in Germany, the Netherlands, Poland, Great Britain and parts of Northern Europe. It is also popular in North America.

Rhubarb is a true seasonal vegetable. You mainly get it in spring and early summer. The key times are:

Outside the season you can sometimes find rhubarb frozen or processed, for example as compote, jam or juice. Fresh

Rhubarb (Rheum rhabarbarum) is an herbaceous, perennial crop plant in the knotweed family (Polygonaceae). Botanically notable are the robust, often reddish leaf stalks, while the large, heart-shaped leaf blades are not suitable for consumption because of their content of oxalic acid and other antinutritional substances. The plant forms underground rhizomes from which new shoots emerge in spring. Originally native to Central Asia, rhubarb reached Europe in the 18th and 19th centuries as a useful plant and became established both in agricultural systems and in home gardens.

The morphological structure of rhubarb is characterized by fleshy, cylindrical to slightly angular leaf stalks whose color can vary from green through pink to ruby red. The coloration correlates with pigment profiles, particularly anthocyanins such as cyanidin- and pelargonidin-derived compounds. While color influences sensory expectations, chemical-analytical studies show that sugar content differs only moderately between green and red varieties; the perceived sweetness impression results primarily from the interplay of acids, aroma compounds and texture.

Components and nutritional profile: rhubarb is low in calories (typically about 20–25 kcal/100 g) and high in water. It provides fiber, small amounts of protein and minerals such as potassium, calcium, magnesium and traces of iron and manganese. Vitamins are present in moderate concentrations, especially vitamin K, vitamin C and folate. Characteristic is the high acid content (mainly malic and citric acid), complemented by oxalic acid, which can form insoluble calcium oxalate with calcium. This results in sensory and nutritional particularities: the pronounced tart taste and the potential influence on calcium bioavailability. Oxalic acid content varies by cultivar and tissue and is highest in the leaves; only the stalks are edible.