Extraction, separation and modification of sweet glycosides from the stevia rebaudiana plant

A process for the purification of rebaudioside A and stevioside, which comprises the following steps:

• a) dissolving the mixture of sweet glycosides obtained in step (1e) with ethanol, heating the solution and then cooling the solution to precipitate Rebaudioside A;
• b) filtering the solution to recover the precipitate Rebaudioside A and a filtrate containing other sweet glycosides;
• c) suspending the crystallin Rebaudioside A obtained in step (2b) in ethanol-water solution, heating and then cooling the solution to precipitate the Rebaudioside A at a higher purity;
• d) recovering the higher purity Rebaudioside A.
• e) treating the solution obtained in step (b) with bentonite;
• f) treating the solution obtained in step (b) with beta cyclodextrin;
• g) desalting and concentrating the filtrate from step (f) by heating and evaporating to dryness to obtain powdered Stevioside;
• h) suspending the crystallin stevioside obtained in step (2) in ethanol, heating and then cooling the solution to precipitate the Stevioside at a higher purity;
• i) recovering the higher purity Stevioside.