Abstract:
Herbal tea or a tisane is a mixture of dried plant
parts used for medicinal purposes. Present study
was aimed to develop herbal green tea bags
with Osbeckia octandra (Heen bovitiya) leaves
predominantly and evaluate the effect of
infusion time and temperature on their total
phenolic (TP), total flavonoid (TF) contents and
in vitro antioxidant activity. Six different tea
bags (T1 to T6) were prepared by incorporating
dried O. octandra (leaves), Camellia sinensis
(leaves), Zingiber officinale (rhizomes), Vanilla
planifolia (pods) and Allium sativum (bulbs) in
different proportions. Each herbal tea bag was
infused at a constant infusion temperature of
100 ⁰C for 3, 5 and 7 minutes and for a constant
infusion time of 7 minutes at different
temperatures; 100, 90 and 80 ⁰C. TP, TF
contents, in vitro radical scavenging activity
and ferric reducing antioxidant power of all tea
extracts were determined by spectroscopic
analysis. Data were analyzed with one sample t test. All infusions were rich in phytochemicals;
phenols, flavonoids, tannins, terpenes,
triterpenoids, phytosterols, saponins, alkaloids,
amino acids and carbohydrates. TP, TF contents
and in vitro antioxidant activity of the
formulated tea bags were significantly higher
after the addition of O. octandra leaves and the
values were different at different infusion
conditions (p<0.05). At constant infusion time
of 7 minutes, TP, TF contents and antioxidant
activity of O. octandra incorporated green tea
bags were higher when infused at 80 ⁰C
compared to 90 ⁰C and 100 ⁰C. At constant
infusion temperature of 100 ⁰C, the values were
higher for the formulated green tea bags when
infused for 7 minutes compared to 3 and 5
minutes. Hence, it was concluded that the
formulated tea bags with O. octandra leaves
were rich with antioxidants and that they should
be brewed for a long time period (7 minutes) at
a low temperature (80 ⁰C).
