Optimization of the Ultrasound-assisted Extraction of Saponins from Germinated Quinoa and the Evaluation of the Radical-scavenging Activity

Abstract

This study aimed to optimize the extracting process for the content of saponins in germinated quinoa. Saponins from germinated quinoa was ultrasonically extracted. This study the effects of extractive temperature, extractive time, liquid ratio and ethanol volume fraction on the content of saponins in germinated quinoa under the condition of single factor. The extraction process of saponins in germinated quinoa was optimized by the Box-behnken center combination and response surface method (RSM). Results indicated that the highest saponins content of 27.4012 mg/g in germinated quinoa was obtained after the optimized conditions which was extractive temperature 54 °C, extractive time 15 min, liquid ratio 1:50, ethanol volume fraction of 75%. The content of saponins in germinated quinoa was 2.6 times higher than unwashed quinoa seeds. The saponins after being optimized have strong antioxidant properties. This finding suggested that the ultrasonic method is beneficial to the extraction of saponin from germinated quinoa, which provides a theoretical basis for the enrichment of saponins in germinated quinoa.