Identification, Quantification, and Sensory Characterization of Steviol Glycosides from Differently Processed Stevia rebaudiana Commercial Extracts

Abstract

Stevia rebaudiana is known for its sweet-tasting ent-kaurene diterpenoid glycosides. Several manufacturing strategies are currently employed to obtain stevia sweeteners with the lowest possible off-flavors. The chemical composition of four commercial S. rebaudiana extracts, obtained by different technologies, was characterized using UHPLC-ESI-MSn. The composition of one of the ethanol crystallized extracts (EC2) was entirely rebaudioside A, whereas the enzymatically modified (EM) extract contained the lowest concentration of this compound (2.7 mg/100 mg). The membrane purified (MP) extract had the highest content of minor natural steviol glycosides (23.7 mg/100 mg total extract) versus an average of 2.4 mg/100 mg total extract for the EC samples. Thirteen trained panelists evaluated sweetness, bitterness, licorice and metallic of all four extracts. The highest licorice intensity (p≤0.05) was found for MP. Both samples, EC1 and EC2, despite their different chemical composition, did not show any significant differences in sensory perception.