Comparative Standardization and Physicochemical Evaluation of the Leaves of Stevia rebaudiana Bertoni from Different Geographical Sources

Stevia rebaudiana Bertoni, a natural non-caloric substitute to conventional sugar, is also popular as the “sweet herb of Paraguay”. It is a storehouse of various bioactive constituents mainly, the ent-kaurene diterpene glycosides namelystevioside, rebaudioside A, B, C, D and E. The plant is known to exhibit a wide range of biological activities like hypoglycemic, anti-oxidant, anticancer, antibacterial activities. The present research is based on a comparative standardization and physicochemical analysis of the dried leaves of five varieties of Stevia rebaudiana procured from five different geographical locations of India viz., Delhi, Surat, Kangra, Bangalore and Indore. Fluorescence analysis of the powdered leaves was carried out as a means for identification. The standardization parameters included determination of foreign matter, ash values, loss on drying, extractive values. Preliminary phytochemical screening was also performed. The results from the current study can prove to be an indicator to differentiate the five varieties based on their standardization parameters.