HPLC analysis The tea extracts were filtered and run
through a C18 column in a Shimadzu LC 10 A (Japan)
instrument using a gradient mobile phase consisting of
solvent a (0.05% orthophosphoric acid in millipore water)
and solvent b (15% acetonitrile). The samples were
analysed at 280 and 360 nm for catechin and Tf,
respectively (data not shown).
Colour estimation Quantitative colour measurements of the
samples were performed using a computerized spectrophotometer
(Konica Minolta CM-3500d, Osaka, Japan) and
values were calculated by CIE system (CIE 1974).