The impact of SFE, using CO2 and
either water or different mixtures of ethanol−water as
cosolvents, on the recovery of steviol glycosides from Stevia
has been studied by several research groups (Table 2). For
instance, an increase in steviol glycoside’s recovery was found
after applying SFE (3−3.4%), in two steps, (a) the pretreatment
of the leaves by SFE; (b) the extraction of the Stevia
glycosides by SFE using CO2 as solvent and water and/or
ethanol as cosolvent, compared to that of the conventional
extraction process.70 In this line, other authors also obtained
50% and 72% recovery of the original stevioside and
rebaudioside A, respectively, when using a two-step SFE
process: (1) CO2 extraction and (2) CO2 + water extraction.7