Ethanolic fermentation from red ginseng extract using Saccharomyces cerevisiae and Saccharomyces carlsbergensis

The pH of red ginseng extracts fermented with Saccharomyces cerevisiae and Saccharomyces carlsbergensis decreased rapidly during 3 days of fermentation, with no further significant change thereafter. After 20 days of fermentation, a relatively small difference remained in the acidity of extracts fermented with S. cerevisiae (0.54%) and S. carlsbergensis (0.58%). Reducing sugar in the S. cerevisiae and S. carlsbergensis extracts decreased from 258.6 to 45.4 and 43.2 mg/mL glucose equivalents, respectively; and ethanol contents increased from 1.5% at day 0 to 16.0 and 15.0%, respectively, at day 20. Ginsenosides Rb₁, Rb₂, Rc, Re, Rf, and Rg₁ decreased during the fermentation with S. cerevisiae, but Rd and Rg₃ increased by day 12. Ginsenosides Rb₁, Rb₂, Rc, Re, and Rg₁ decreased gradually in the extract with S. carlsbergensis, but Rd and Rg₃ were increased at day 6 and 9, respectively.