VietNamNet Bridge - With a new extraction process discovered by Hoang Phuong Lan, MA, it will be more simple to extract stevioside, the element responsible for the sweet taste of leaves from stevia rebaudiana.

Hoang Phuong Loan, the author of 'royal sweetener'

The application of extraction technology in making sweetener from stevia plant creates a type of sugar 300 times sweeter than refined sugar. 

The type of sugar does not ferment, contains little energy and does not disintegrate. It tastes delicious and can replace sugar in people’s daily use.

Stevia rebaudiana first appeared in Vietnam a long time ago and it is growing in many areas, including Ha Giang, Cao Bang and former Ha Tay provinces in the north, and in Lam Dong and Dak Lak in the central region.

The application of extraction technology in making sweetener from stevia plant creates a type of sugar 300 times sweeter than refined sugar.

However, stevia plants fell into oblivion because of many reasons. The demand was low because people were not aware of its importance, while the extraction technology was too complicated, which made the production cost high.

However, the stevia plant recently regained its important position as experts have advised to use the plant as a kind of natural sweetener instead of refined sugar. People now tend to use stevia because it helps reduce the risk for obesity and prevent some diseases.

Under the stevioside extraction technology used widely in the world, scientists use an organic solvent, mostly methanol or mixture of methanol and water. The process is complicated with many stages needed, which is costly.

The technology has been used for many years as the only extraction solution, though scientists understand that organic solvents are toxic and cause environmental pollution. In general, countries have to spend big money to treat the waste discharged by the extraction process.

Lan, who was well aware of the weak point of the solution, decided to work on a process which extracts stevioside in a simple way and avoid a negative impact on the environment.

Lan’s efforts have brought the desired effects. Her solution extracts stevioside in a safe way with 90 percent of stevioside obtained, which means high efficiency. The equipment needed for the extraction process is very simple and not too expensive, thus suitable to Vietnamese conditions. 

Under the new extraction process, stevioside in stevia plant is extracted mostly by water at the temperature of 1000oC and some supplement mineral salt substances which help stabilize the concentration of extract.  The extracts can be collected with a centrifuge which exclude residues.

Raw extracts of a dark color will be treated with diatomite and then refined with activated carbon. The extract fluid to be collected will be pure and colorless. 

Kham Pha