Abstract

Stevia rebaudiana is a plant native of South America, and its active constituents are considered, by Food Science researchers, the "sweeteners of the future." Therefore, research on this plant has been increased. Stevia is a source of natural diet sweetening, without calories and safe for health. Its crude extract, however, is foul-smelling, bitter tasting, and dark brown; subsequent purification is essential to obtain a product of commercial quality. In this work, adsorption in modified zeolites associated with the filtration with membranes was applied in order to purify stevia crude extract. For the adsorption process, 40 g of CaX modified zeolites were used. In the ultrafiltration process, membranes with porosities of 0.05, 0.1 and 0.2 μm were used. The transmembrane pressure was fixed at 2, 4 and 6 bar for each membrane. The best conditions of flux were obtained with the 0.2 μm membrane and 6 bar, resulting in high clarification and recuperation of stevioside (91.75%). This work shows that the adsorption in modified zeolites associated with the membrane filtration is promising for stevia extract purification.

Recommended Citation

Silva, Flávia Vieira; Bergamasco, Rosângela; Andrade, Cid Marcos G.; Pinheiro, Nanci; Machado, Nádia Regina Camargo Fernandes; Reis, Miria Hespanhol M.; de Araújo, Álvaro Alberto; and Rezende, Suzana Lemanski (2007) "Purification Process of Stevioside Using Zeolites and Membranes," International Journal of Chemical Reactor Engineering: Vol. 5: A40.
Available at: http://www.bepress.com/ijcre/vol5/A40