sentences:  Thearubigin
  
  Thearubigins are polymeric polyphenols that are formed during the enzymatic oxidation and condensation of two gallocatechins (epigallocatechin and epigallocatechin gallate) with the participation of polyphenol oxidases during the fermentation reactions in black tea.Thearubigins are red in colour and are responsible for much of the staining effect of tea.