Tea extract is to get the tea’s active ingredient by soaking the tea leaves
in the hot water. The aim of the tea extract is to get the tea’s active
ingredient efficiently while at the same time keeping the tea’s original color,
smell and taste as much as possible, and preventing the ingredient that muddies
the tea from coming out.
It adopts fractional extraction. The first
extraction is low temperature extraction. The aim is to preserve the original
taste of the tea and have the heat sensitive ingredient dissolved in the
solvent. The second extraction is high temperature extraction. The aim is to
extract the active taste ingredient. While during the process, non-polyphenols
may come out from the tea leaves and muddies the tea soup. But through the
control of extract parameters, this could be resolved.
The extracted tea
needs to be purified to get rid of the impurity, gelatin, and non-polyphenols
macromolecular compound so as to prevent the tea from becoming muddy or
precipitant. Two purified means are available, low temperature settling method
(by high speed centrifugal) and membrane separation method (by
ultra-filtration). The two means could be used separately or together.