Description of the plant
Stevia rebaudiana Bertoni is a perennial herbaceous plant and is part of the Asteraceae family. This family includes well known plants such as dandelion, sunflower and chicory. The plant was first described botanically by Dr. M.S. Bertoni in 1899. The lanceolate leaves are about 5 cm long and 2 cm wide and are planted crosswise, facing each other. In the wild, the height of the plant varies from 40 to 80 cm but when cultivated, the Stevia can become 1 metre high. Stevia can be grown on relatively poor soil. The plants can be used for commercial production for 5 years or more, during which twice a year a harvest takes place of the part of the plant that is above the ground. The roots remain in place and so the plant springs up. Plants which are 1 metre high have a dry weight of 70 g on average. The dry weight of the leaves can vary from 15 to 35 g per plant.
Origin and history
The history of the culture of Stevia mainly stems from Paraguay and Brazil. Originally Stevia only grew in the northern regions of South America. The plant has been known for centuries by the native Guaranay-Indians for the sweet taste of its leaves. They use it, amongst other things, to make "mate" herbal tea. Stevia is often described as "sweet herb of Paraguay" and is referred to as the "sweetest plant of the world". Such terms show the amazing power of this herb.
Europe first came in contact with the herb when, in the 16th century, the Spanish rulers learned of the "sweet honey herb" used by the natives of South America. In spite of the description of the plant by the Paraguayan botanist M.S. Bertoni in 1899, the research and commercial use of the plant had a slow start.
Around 1908 the presence of several sweeteners in Stevia was reported but it only became possible to crystallise stevioside in 1931. During World War II, the allies considered extracting stevioside commercially as an alternative for sugar supplies which were running out. Unfortunately at that time the technology needed for industrial production was lacking. Because of the restriction on the use of artificial sweeteners, imposed around 1970 in Japan, the research in Japan for the commercialisation and utilisation of stevioside made quick progress. For over twenty years now, Japanese consumers have been using the extract from the plant as a safe, natural, non-calorific sweetener. It is currently the most used sweetener on the Japanese and Korean market. The commercial production takes place mainly in Paraguay, Uruguay, Central America, The United States, Israel, Thailand and China.
The refined Product
Stevioside is a white, crystalline powder that is extracted from Stevia leaves. The extraction can be done in a way which is friendly to the environment. Scientists call stevioside a "noble molecule". It owes this epithet to a number of qualities :
the product is 100 % natural
no calories
up to 300 times sweeter than sugar