The industrial process of extraction of steviol glycoside is often the least understood aspect in entire value addition chain of Stevia. All the information available in the public domain about the extraction process is either too technical for general audience or infested with overhyped marketing jargon. Let me try to explain the process in detail in simple and straightforward language.
The extraction of steviol glycosides from Stevia leaves and its purification involves several steps. The major steps are (1) Primary extraction with water or solvent, (2) Purification of the liquid extract, (3) Separation of solid glycosides from purified liquid extract, (4) Solvent recovery and (5) Further purification of the solid glycosides. Now let me explain the processes one by one -