The stevia plant Stevia rebaudiana
The stevia plant
Stevia rebaudiana Bertoni is a small, shrubby plant and belongs to the sunflower family (Asteraceae or Compositae). The stevia plant is native to Paraguay and prefers sandy soils near water. In nature, the stevia plant can reach a height of up to 75cm.
Stevia rebaudiana Bertoni is the Latin name of the stevia plant. This consists of the genus name Stevia rebaudiana the species name and the subspecies name Bertoni. There are over 150 other stevia plant species, of which only the Stevia rebaudiana species include the sweet steviol glycosides. This Stevia plant is therefore also known as honey leaf Stevia, Sweet Herb of the indigenous population, the Guarani and Mato Grosso Indians in Paraguay and Brazil. In the Guarani language of Paraguay, the sweet herb is also caá Jee Kaa Hee or called Yerba Dulce.
The botanist Moisés Bertoni first discovered the sweet constituents of the stevia plant. The individual components of the stevia leaves, stevioside, rebaudioside A to F which were broken down and analyzed by the chemist Ovidio Rebaudi.
The origin and distribution of stevia
The highlands of Argentina, Brazil and Paraguay from 22 to 23 south latitude and from 55 to 56 western longitude is the natural home of the stevia plant. The soil texture and moderately humid climate in the border area between Argentina, Brazil and Paraguay form an ideal habitat for the species Stevia rebaudiana plant, with an annual average temperature of 21 ° C and an annual precipitation 1500-1800 mm. On the sandy, acidic and clay plateaus of Amambai, in Mato Grosso do Sul in the border area between Brazil and Paraguay, grow the sweet stevia species particularly well.
Today is the stevia plant in Latin America, South East Asia and cultivated almost all continents of the world for the production of sweet ingredients, the steviol glycosides and rebaudioside. The recovery of the sweeteners is in a complex extraction process.
The Stevia Botany
The Stevia rebaudiana plant is a shrubby plant and belongs to the sunflower family (Asteraceae or Compositae). The stevia plant is native to Paraguay and prefers sandy soils. In frost-free climate, the stevia plant develops a strong root stock of the perennial shoots grow up to one meter high stevia. The stevia plant belongs to the shallow rooting, that is, the stevia roots spread dished out in the upper soil layers.
The Stevia leaf
From the stem of the stevia plant itself Lanzettblätter develop sickle-shaped, pointed serrated leaves. The light to dark green, up to 8 inches long stevia leaves are arranged opposite one another and have trichomes on the leaf surface. Depending on the stevia plant Stevia leaf shapes can be oval or diamond-shaped.
The ingredients of dried Stevia rebaudiana leaves
In the leaves of Stevia rebaudiana, the sweet-tasting components that steviol glycosides stevioside or form. These give the stevia plant its sweetness. The greatest significance of the steviol glycosides and rebaudioside A. There are currently more sweeteners such dulcoside A, rebaudioside B, C, D, E, F and steviolbioside in the leaves of the stevia plant. Based on the dry weight of the Stevia leaves Stevia leaf contains a 5-10% stevioside, rebaudioside A 2-4%, 1-2% rebaudioside C and 0.4-0.7% dulcoside A. Dried stevia leaves are 20 to 30 times as sweet such as sugar and the extract obtained therefrom, steviol glycosides up to 300 times sweeter.
Other ingredients of the Stevia leaves
For proteins and carbohydrates provide Stevia rebaudiana leaves a good source dar. The content of inorganic minerals is attributed to the high ash content. Also of importance are the minerals contained in the Stevia leaves and secondary plant substances.
The stevia flower
Stevia the flowers are arranged in an irregular inflorescence and about 7-15 mm. The flower heads of Stevia rebaudiana are terminal and combined into cymes. These consist of five white-flowered cylindrical flower heads. A stevia rebadiana drive can have between 10 and 200 flower heads. The fruit of the stevia plant is thin and long and 4 - to 5 edges.
A feature of the stevia flowers is the self-sterility (Selbstunfruchtbarkeit). Plants are referred to as the self can not fertilize. After pollination with pollen of its own species (genotype), the remains of seed formation. The wind takes it under natural conditions in which he carries the pollen from the flower petals of Stevia Stevia Stevia plant to plant, and only as a seed formation is possible. This type of sexual reproduction is also called wind pollination and also occurs in varieties of apple, pear and cherry.
The formation of stevia seeds
The seeds Stevia is about 3 mm long and belongs to the family of one-seeded indehiscent fruit (achene, like the dandelion). The seeds of the stevia plant is equipped with an airworthy feathery crown of hair. After the maturation covered the stevia seeds, which form in seed cups, easy out. Stevia is a light seeds on moist soil around the seed time is at a nucleation temperature of 20-25 Gradbis to 14 days.
Stevia seeds is known for its low germination rate of 12 to 15 percent, even with optimal seed. Another much simpler way is the vegetative propagation of Stevia plant switches from cuttings. In many nurseries and garden centers can buy a stevia plant and keep it in the garden during summer.
The vegetative propagation and cultivation of Stevia
The vegetative propagation of Stevia plant from cuttings is much easier than to bring stevia seeds to germinate.