Abstract:
The present study was conducted to evaluate the physicochemical and functional properties
of sepals of Mussaenda frondosa to develop a functional tea. M. frondosa is one of
the edible species of genus Mussaenda which contains many types of medicinal products
and phytochemicals. Hot water (HW), hot ethanol (HE), and defatted hot ethanol
(DHE) extracts were prepared from the dried sepals of M. frondosa and the hot water
extraction was optimized at different temperatures with and without ultrasound sonication.
Antioxidant activity of each extract was assessed using DPPH radical scavenging
assay. Hypoglycemic potential was determined using alpha amylase inhibition assay.
The highest TPC (114.42 ± 0.6 mg GAE/g) and TFC (66.47 ± 0.3 mg QE/g) were
shown by the DHE subsequent to its high extraction yield (46.71 ± 0.2%). The highest
antioxidant and alpha amylase inhibition activities were also shown by the DHE with
the IC50 value of 24.06 ± 0.2 µg/ml and 87.61 ± 0.2 μg/ml respectively. Ultrasound
sonication at 80◦C significantly enhanced the TPC, TFC, antioxidant activity and the
alpha amylase inhibition activity (p < 0.05) of water extract. Hot water extracts did
not show any toxicity as evaluated by the brine shrimp lethality bioassay. A tea was
formulated by blending different proportions (30, 40 and 50%) of dried sepals of M.
frondosa with black tea. The formula containing 40% M. frondosa was selected from
the sensory analysis (hedonic ranking test, 30 untrained panelists) and subjected to
further analysis. Further, TPC, TFC, antioxidant and hypoglycemic activities of M.
frondosa incorporated tea were significantly higher (p < 0.05) than that of black tea.
This study revealed that sepals of Mussaenda frondosa would be a potential source for
the development of new functional tea with enhanced health benefits.
