Stevia is a kind of perennial herbs, which is native to the Oman mountains on the border between Paraguay and Brazil. Centuries ago, Paraguay natives used the leaves of this small, herbaceous, semi-bushy, perennial shrub to sweeten their bitter drinks. Gaurani Indians extensively used this plant for more than 1500 years.
In 1888, Dr. Moises Santiago Bertoni discovered this plant at Paraguay. The plant was scientifically named as S. rebaudiana after a Paraguayan chemist Dr. Rebaudi in 1905. In 1931, two French chemists isolated the glycosides which is secondary metabolites responsible for the sweet taste of Stevia. The leaves of Stevia contain a natural complex mixture of eight sweet diterpene glycosides, including isosteviol, stevioside, rebaudiosides (A, B, C, D, E, F)，which are 250 to 300 times as sweet as sucrose. In 1971, Morita Kagaku Kogyo Company in Japan started producting commercial stevia. And China successfully introduced stevia from Japan in 1977. Since 2006, China has become the world's largest producer and exporter of stevia, accounting for 80 percent of the world's stevia market.
In addition to its high sweetness characteristics, stevia is well known to exert beneficial effects on human health such as antimicrobial, antiviral, anti-hypertensive, anti-hyperglycaemic, hepatoprotective, and so on. It is considered as a natural sucrose substitute sweetener
Stevia was approved by the U.S. in 2008 and approved by the European Union in 2011 as a safety food additive. Soon afterwards, the European Union, South Korea, the United States, China and India have introduced the relevant standards for the use of stevia. At present, it is widely used in many parts of the world as sweetener and grown commercially in Central America, Korea, Paraguay, Brazil, Thailand and China.
In recent years, many countries around the world have begun to focus on metabolic diseases such as diabetes, hypertension and obesity. According to latest survey of International Diabetes Federation (IDF), there were 415 million diabetics all over the world. And among them, 115 million are from China. And according to IDF's prediction, if there is no intervention, the number of diabetics in the world will reach 642 million in 2040 and the number of diabetics in China will grow up to 154 million. The main cause of diabetes is excess sugar intake. Too much sugar intake can induce the decrease of the levels of HDL-C and the increase plasma glucose, insulin and triglyceridesg levels in blood, lead to high blood pressure and increase the risk of heart disease and type 2 diabetes.
In response to the high incidence of metabolic diseases such as obesity and diabetes, sugar taxes have been introduced in many countries to limit the use of sugar added to food. In March 2016, in the British government's annual budget meeting, Britain's chancellor of the exchequer George osborne said, begin from 2018, sugary soft drinks manufacturers must pay tax for the sugar in the drink. At that time, all soft drinks produced and imported in the UK are taxed at a rate of more than 5 grams per 100 ml and over 8 grams per 100 ml, with a top rate of 20 percent. And in the United States, 33 states have enacted sugar tax laws, while New York also has tried to ban the sale of drinks contained excess sugary. In Mexico, the government has imposed an additional 10% tax on sugary drinks early in January 2014. Until now, there are already a number of countries have taxed on sugary drinks, such as France, Hungary, Belgium, Norway and so on. A study in 2015 showed that about 85% of Australians support the introduction of sugar tax, which is used to combat obesity.
