Modeling and optimization of ultrasound-assisted green extraction and rapid HPTLC analysis of stevioside from Stevia Rebaudiana

Stevioside is the major constituent of the Stevia Rebaudiana plant. The aim of this study is to appraise optimum procedure conditions for extraction of stevioside from Stevia Rebaudiana by Peleg’s mathematical methodology. Stevioside from dried leaves of Stevia Rebaudiana was extracted by means of probe type sonication system using glycerol as a green and generally recognized as safe (GRAS) solvent. High Performance Thin Layer Chromatography (HPTLC) was used as a very efficient, rapid and precise method for stevioside detection and analysis. Results demonstrated that the optimum conditions for ultrasound-assisted extraction (UAE) of stevioside from Stevia Rebaudiana are glycerol as solvent, temperature of 70 °C, plant to solvent proportion of 1:30, plant powder particle size of 0.075 mm, 200 W ultrasound irradiation power and 20 kHz ultrasound irradiation frequency. The comparing experimental results for Ceq of extracted stevioside with calculated values from Peleg’s mathematical model showed good and acceptable agreement. As a consequence, it was concluded that the ultrasound-assisted extraction is an efficient, fast, and economic method for extraction of stevioside from Stevia Rebaudiana in comparing with Soxhlet and maceration methods. Moreover, selected mathematical model displays the system with an acceptable accuracy which can predict the optimal conditions for extraction of stevioside those are close enough to experimental results.Practical Applications This investigation presented a mathematic model and experimental approach for the optimization of stevioside content of Stevia Rebaudiana using the ultrasound-assisted extraction and HPTLC analysis. Compared with the classic methods for optimizing of stevioside using the mathematic approaches or chemical experiments, the Peleg’s method is more precise and convenient. Moreover using ultrasound and HPTLC as extraction and analysis method, respectively, provides safer, rapid, and simple way for their stevioside extraction. Therefore, the method demonstrated in the present investigation could be used to extract the stevioside of Stevia Rebaudiana in food and beverage industries.