[1] Thearubigins are red in colour and are responsible for much of the staining effect of tea.
The colour of a black tea, however, is affected by many other factors as well, such as the amount of theaflavins, another oxidized form of polyphenols.
Thearubigins were first studied by Roberts, E. A. H. in the 1960s[3] by the means of spectroscopy[4] or by fractionation or paper chromatography.
[7] Quantification methods were based on Porter's assay in 1995[8] and separation made on C18 sorbent cartridges in 1992.
[13][14] It has been shown in 2009 that thearubigins formation in black tea is correlated with catechins depletion.