Simple extraction and membrane purification process in isolation of steviosides with improved organoleptic activity

• Published in: Advances in bioscience and biotechnology Vol. 3; no. 4; pp. 327 - 335
• Main Authors: Rao, Adari Bhaskar, Prasad, Ernala, Sridhar, Goka Roopa Sundergopal, Ravikumar, Yerrapragada Venkata Lakshmi
• Format: Journal Article
• Language: English
• Published: 01.08.2012
• Subjects: Antioxidants; diterpenes; glucosides; Leaves; Purification; Stevia; Stevia rebaudiana; steviol glycosides; stevioside; Sucrose; Sugar; Sweet taste; Sweeteners
• ISSN: 2156-8456; 2156-8502
• DOI: 10.4236/abb.2012.34048

In recent years there has been increasing demand for natural non-nutritive high intensity sweeteners with low-calorie value as an alternative to sucrose. Ex- tracts of the leaves of Stevia rebaudiana (Bertoni), have been known for their sweet taste. Steviosides and rebaudioside-A are the two major diterpenoid glucosides components present in the leaf extracts of the stevia, these glycosides are 300 times sweeter than sugar and also exhibits wide therapeutic activity. The conventional methods of isolation of steviosides in- volve long extraction and purification procedures; therefore optimization of product yields is a challeng- ing problem. The present study, establishes a new im- provised process of extraction of steviosides from the stevia leaves in which the dry treated leaves were grounded, defatted, and extracted through pressu- rized hot water extractor (PHWE), followed by puri- fication and concentration of the sweet glycosides through ultra (UF) and nano (NF) membrane filtra- tion in obtaining high (98.2%) purity steviosides. This process established "green" method for isolation of high quality steviol glycosides, with improved final yield is 10.1% from 11% of crude leaf extract and ob- served the improved organoleptic and biological ac-tivity (antioxidant). Thus the method confirms a sim-ple, in-expensive and eco-friendly process in obtain-ing pure steviosides.