Authors: Angela Periche Maria Luisa Castelló Ana Heredia Isabel Escriche
Publish Date: 2015/03/01
Volume: 70, Issue: 2, Pages: 119-127
Abstract
This study evaluated the application of ultrasound techniques and microwave energy compared to conventional extraction methods high temperatures at atmospheric pressure for the solid–liquid extraction of steviol glycosides sweeteners and antioxidants total phenols flavonoids and antioxidant capacity from dehydrated Stevia leaves Different temperatures from 50 to 100 °C times from 1 to 40 min and microwave powers 198 and 330 W/g extract were used There was a great difference in the resulting yields according to the treatments applied Steviol glycosides and antioxidants were negatively correlated therefore there is no single treatment suitable for obtaining the highest yield in both groups of compounds simultaneously The greatest yield of steviol glycosides was obtained with microwave energy 330 W/g extract 2 min whereas the conventional method 90 °C 1 min was the most suitable for antioxidant extraction Consequently the best process depends on the subsequent use sweetener or antioxidant of the aqueous extract of Stevia leaves
Keywords: