15 research outputs found
Influence of shooting period and extraction conditions on bioactive compounds in Turkish green tea
A gradient based facile HPLC method for simultaneous estimation of antioxidants extracted from tea powder
Extraction of caffeine and catechins using microwave-assisted and ultrasonic extraction from green tea leaves: an optimization study by the IV-optimal design
Effects of alternative steeping methods on composition, antioxidant property and colour of green, black and oolong tea infusions
Cold water steeping is reported to maximise tea
health benefits, but requires long infusion time. In this work,
the employment of a brief hot infusion step followed by ice
addition was evaluated. The comparison of this innovative
method with hot and cold steeping was investigated on
green, black and oolong teas. Catechins, xanthines and
gallic acid content, antioxidant power, total phenolics
and colour analysis were evaluated. Hot infusion shown
rapid extractive power, but relevant compound degradation.
On the contrary, cold infusion extracted higher
level of healthy molecules with slow kinetic. The innovative
method achieved in short time similar properties
of cold infusion in terms of antioxidant power. As for
bioactive compounds, such as gallic acid and epigallocatechin
gallate, highest values, about double than in
hot infusion, were recorded for green and black teas.
This steeping method may represent an alternative approach
for industrial beverage preparation