A. Degenhardt et al., Isolation of black tea pigments using high-speed countercurrent chromatography and studies on properties of black tea polymers, J AGR FOOD, 48(11), 2000, pp. 5200-5205
Isolation of theaflavins and epitheaflavic acids from black tea using high-
speed countercurrent chromatography (HSCCC) on a preparative scale is demon
strated. HSCCC also enabled the isolation of a polymeric fraction from blac
k tea. According to Roberts' classification, the polymeric fraction mainly
consisted of SII thearubigins (TR). HPLC analysis showed that the isolated
material is free of any known chromatographically resolved tea constituents
and eluted from reversed-phase packings as a convex "hump" (a broad signal
). The antioxidant activity of the TR fraction was 3.6 mmol of Trolox equiv
alents per gram. The total phenolic content of this fraction was determined
to be 34.7 g/100 g (as gallic acid equivalents).