Determination of proanthocyanidin content -
Quantification of the total proanthocyanidin content
of the TSCEs was carried out using the alchohol-HCl-
Fe3+ method, as described previously20. In brief, a test
solution of TSCEs (0.25 mL, 500 was added
to 3 mL of n-butanol-HCl (95:5 v/v), and 1 mL of
10% NH4Fe(SO4)2.12H2O in HCl solution was then
added. The reaction mixture was shaken and
incubated at 95 for 40 min. A red colouration was
developed while the reaction mixture was cooled to
room temperature. The absorbance at 500 nm was
measuredagainstareagentblank.The
proanthocyanidin content was expressed as the
observed absorbance value.
Determination