Isolation of β-carotene, α-carotene and lutein from carrots by countercurrent chromatography with the solvent system modifier benzotrifluoride.
A carotenoid purification method with dual-mode countercurrent chromatography (CCC) for β-carotene, α-carotene and lutein from a fresh carrot extract was developed. The fluorinated liquid benzotrifluoride (IUPAC name: (trifluoromethyl)benzene) was used as a novel modifier in the non-aqueous ternary solvent system n-hexane/benzotrifluoride/acetonitrile. The ternary phase diagram of the type I solvent system was used to select two-phase solvent mixtures which enabled an efficient preparative separation of α-carotene, β-carotene and lutein from concomitant pigments in crude carrot extract. By means of the modifier, high separation factors (α ≥ 1.2) were obtained, allowing baseline resolution between α-carotene and β-carotene due to specific chemical interactions such as π-π molecular interactions. After optimizing the injection step with a pseudo-ternary phase diagram, 51 mg of β-carotene, 32 mg of α-carotene and 4 mg of lutein could be isolated from 100.2mg crude carrot extract in a short time and with high purities of 95% and 99% by using dual-mode CCC, respectively. Temperatures > 22°C had a negative impact on the separation of α-carotene and β-carotene.
Institute of Food Chemistry (170b), University of Hohenheim, Garbenstr. 28, D-70599 Stuttgart, Germany.
Michael
M
Englert
Institute of Food Chemistry (170b), University of Hohenheim, Garbenstr. 28, D-70599 Stuttgart, Germany.
Simon
S
Hammann
Institute of Food Chemistry (170b), University of Hohenheim, Garbenstr. 28, D-70599 Stuttgart, Germany. Electronic address: walter.vetter@uni-hohenheim.de.
Walter
W
Vetter
D000097:Acetonitriles / Q000737:chemistry; D002338:Carotenoids / Q000032:analysis / Q000302:isolation & purification*; D003377:Countercurrent Distribution / Q000379:methods*; D018552:Daucus carota / Q000737:chemistry*; D005464:Fluorobenzenes / Q000737:chemistry*; D006586:Hexanes / Q000737:chemistry; D014975:Lutein / Q000032:analysis / Q000302:isolation & purification*; D012997:Solvents / Q000737:chemistry*; D013696:Temperature; D019207:beta Carotene / Q000032:analysis / Q000302:isolation & purification*
D000097:Acetonitriles; D005464:Fluorobenzenes; D006586:Hexanes; D012997:Solvents; D019207:beta Carotene; C026385:n-hexane; D002338:Carotenoids; C041635:alpha-carotene; C044697:benzotrifluoride; D014975:Lutein; C032159:acetonitrile
(trifluoromethyl)benzene; Benzotrifluoride; Carotenoids; Carrots; Countercurrent chromatography