Extraction of rebaudioside-A by sonication from Stevia rebaudiana Bertoni leaf and decolorization of the extract by polymers.
Optimization of steviol glycosides extraction from Stevia rebaudiana Bertoni leaf was carried out by investigating the effects of isopropyl alcohol concentration (60 %, v/v), time (6-24 min), temperature (30 °C) and sonic power (300-480 W) on extraction of rebaudioside A from Stevia rebaudiana leaves and decolorization of the extract by polymer (Separan AP30 and Resin ADS-7). The results showed that isopropyl alcohol was suitable for the extraction of rebaudioside A from Stevia rebaudiana leaves and the yield of rebaudioside A achieved 35.61 g/100 g when the output power was 360 W and treatment time was 18 min. The sonication had influence on the particle size of stevia leaf and the color of the extracted solution. As the sonication intensity increased, the particle size decreased. The colour of differently treated stevia solutions were significantly different (P < 0.05). Separan AP30 and adsorption resin ADS-7 were performed to remove the colour impurity. The results showed that more than 65 % of the coloured impurity was removed by Separan AP30 combined with Calcium oxide (CaO).
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, 214122 People's Republic of China ; Department of Nutrition & Food technology, Faculty of Science and Technology, Omdurman Islamic University, P.O. Box 382, 14415 Khartoum, Sudan.
Mohammed Abdalbasit A
MA
Gasmalla
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, 214122 People's Republic of China.
Ruijin
R
Yang
State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, 214122 People's Republic of China.
Xiao
X
Hua
Decolorization; Extration; Rebaudioside A; Resin ADS-7; Separan AP30; Sonication