Separation and identification of polyphenols in apple pomace by high-speed counter-current chromatography and high-performance liquid chromatography coupled with mass spectrometry.
Apple pomace, a by-product in the processing of apple juice, was investigated as a potential source of polyphenols. Two methods of separation and purification of polyphenols from apple pomace extract were established by combination of gel chromatography with high-speed counter-current chromatography (HSCCC) and solvent extraction with HSCCC, respectively. The optimal separation was performed on a Sephadex LH-20 column using gradient aqueous ethanol as eluting solvent from 0% to 100% in increments of 10%. HPLC analysis indicated that main polyphenols existed in fractions eluted between 40% and 50% aqueous ethanol. The fractions of interest from column were separated by HSCCC with the solvent system hexane-ethyl acetate-1% aqueous acetic acid (0.5:9.5:10, v/v/v). Ethyl acetate fractionation of the apple pomace extract followed by direct HSCCC separation by the same solvent system in the volume ratio of 1:9:10 also produced a good separation of the main polyphenols of interest. Six high-purity polyphenols were achieved tentatively and identified by HPLC/MS: chlorogenic acid (1, m/z 354), quercetin-3-glucoside/quercetin-3-glacaside (2, m/z 464), quercetin-3-xyloside (3, m/z 434), phloridzin (4, m/z 436), quercetin-3-arabinoside (5, m/z 434), and quercetin-3-rhamnoside (6, m/z 448). These results provided a preliminary foundation for further development and exploration of apple pomace.
Cao
Xueli
X
Beijing Technology and Business University, China. caoxl@th.btbu.edu.cn
Wang
Cong
C
Pei
Hairun
H
Sun
Baoguo
B
D000085:Acetates / Q000737:chemistry; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003377:Countercurrent Distribution / Q000379:methods*; D000431:Ethanol / Q000737:chemistry; D005419:Flavonoids / Q000302:isolation & purification*; D027845:Malus / Q000737:chemistry*; D013058:Mass Spectrometry; D010636:Phenols / Q000302:isolation & purification*; D059808:Polyphenols; D012997:Solvents / Q000737:chemistry
D000085:Acetates; D005419:Flavonoids; D010636:Phenols; D059808:Polyphenols; D012997:Solvents; D000431:Ethanol; C007650:ethyl acetate