Inulin extraction from Stevia rebaudiana roots in an autoclave

Abstract

Inulin is a polymer of d-fructose, characterized by the presence of a terminal glucose, and are a major component of Stevia rebaudiana roots. This type of polymer has nutritional properties and technological applications, such as fat substitutes in low-calorie foods and as the coating of pharmaceuticals. The aim of this study was to evaluate an alternative method for inulin extraction, in terms of extraction time and yield, since the traditional method of extraction under reflux is both time and energy consuming. Using the response surface methodology (RSM) with Box-Behnken design it was observed that the alternative extraction method using autoclave presented similar yields to the reflux-based method, but with a shorter extraction time, 121 °C by 17.41 min ¹H Nuclear Magnetic Resonance and Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-ToF-MS) analysis showed that inulin crude extract from S. rebaudiana roots obtained by autoclave extraction had a higher degree of polymerization when compared to those obtained by the traditional method. Thus, it is concluded that the proposed method using an autoclave is a faster alternative for the extraction of inulin.

Keywords: Autoclave extraction; Inulin; RSM; Stevia rebaudiana.