The ethanol-water fatty RJR-2403 solution only contains the water added with the wet biomass and the aqueous ethanol used. When 30 mL of aqueous ethanol/g dry biomass was used, the water content of the ethanol-water solution was 14.5% w/w. An increase in this water content improves the immiscibility of the ethanol-water solution and hexane, which significantly affects the distribution equilibrium of the unsaponifiable lipids between both the ethanol-water and hexane phases, and increases the unsaponifiable lipid extraction yield . Table 3 shows the influence of the ethanol-water phase water content (from 14.5 to 70 % w/w) on the carotenoid extraction yield and the fatty acid recovery yield into the ethanol-water phase, when unsaponifiable lipids were extracted with a hexane to ethanol-water solution ratio of 1:1 (v/v).
Fig. 3. Extraction of carotenoids contained in ethanol-water solutions with varying water content using hexane: influence of the water content in the ethanol-water phase on carotenoid extraction yield in the hexane phase determined by HPLC and spectrophotometry.Figure optionsDownload full-size imageDownload as PowerPoint slide