Stevia has been a source of high-intensity sweets for many centuries, although the sweets encouraged in the early years were often mismatched and had a revolutionary flavor. The stevia plant grows best in tropical and snake-tropical climates. In today’s article, we are going to talk about the stevia extraction process.
Stevia trees grow on small farms in Asia, South America, or other colonial climates. To extract the intense sweetness of the plant, stevia leaves are cut and dried. The leaves are then soaked in hot water. After multiple stages of filtering and centrifugation to concentrate the sweet ingredients of the leaves, the applied refined stevia leaf extract is ready for commercial sale. After a while, the stevia leaves are removed and the ‘tea’ is purified in several steps.
The refined ‘tea’ then passes an ion-exchange chromatography. It is a tube that contains a porous material that captures the steviol glycosides of the decoction with an electric charge and allows the rest to pass through. It can be compared to a sieve, which wants to hold the substance that the rest of it cannot pass after moving away.
Now, the intended steviol glycosides are trapped in the sieve. To access them, the sieve is washed with pure alcohol. The electric charge then releases the grip on the steviol glycosides and they are washed off with alcohol.
The next step would be to remove the alcohol. Many can be separated by a membrane filter, but the remaining alcohol will be removed by distillation.
To remove the yellow color of the syrup, it goes through the activated carbon. It then brings out the steviol glycoside solution which is pressed which is filtered one last time to remove the small residue particles.
Finally, the steviol glycoside solution is then sprayed into a tank filled with hot air under high pressure. When finely divided droplets combine with hot air, most of the steviol glycosides evaporate and fall off like crystalline ice.
The leaves contain mostly stevioside, which instead has a bitter taste and a clear metallic aftertaste. A lot of good taste is provided by Reb-A and the best in the class is Reb M, which is not a fairly bitter or metallic fruit brew, but it tastes almost like sugar (except about 350 times sweeter). The amount of each of the steviol glycosides depends on many things. For example, there is refined stevia which gives much more ribs than other varieties.
In other words, the raw material varies greatly, and with it, the sweetness and taste of the primary extract vary. This makes it difficult to use in food production, as a result, the case may vary from batch to batch. The worst is 50 to 80 percent of the initial excretion of stevioside which is not as enjoyable as Reb A and Reb M is.
For this reason, the primary extract needs to be further refined before it reaches you which develops and produces food or drink.
In the last step, the steviol glycosides are separated. This is done by reinstalling it over and over again.
First, stevia extract is dissolved in alcohol. The steam is directed towards a tube or tower, called a distillation column. The rest of the solution is heated again and the steam is carried to the distillation column once more. The second time, it is basically the crystals of Reb A which are formed.
The fractions thus separated of the reinstalled steviol glycosides are not completely pure from other steviol glycosides. Each fraction is again put through the same process to ‘refine’ the extracts from other steviol glycosides.
Final thought: The whole process of stevia production is called refining – which explains that the plants that extract and refine steviol glycosides are called refineries.