Saturday, May 20, 2017
On cooling, a tea solution becomes opaque and lightens in color. This is due to the formation of tea cream, a colloidal substance which contains the same components as the original extract.
Chemically, tea cream is the complex of theaflavins, TF-gallate, EGCG, ECG, TRs, caffeine, caffeic, acid, gallic acid, ellagic acid, chlorophyll, and bisflavanol A, B.
The conditions under which cream forms determined the chemical composition of the complex and its physical properties. The cream properties are accepted as one of the quality attributes of black tea infusion. The amount of tea cream is a measure of the strength and briskness of black tea.
Since tea cream contains many flavor compounds removal by precipitation decreases the quality of the tea and incidentally decreases the yield of solids from the leaf, so solubilization by maintaining the temperature is a preferred method.
Cream treatment is especially necessary for cold water-soluble instants, which are commonly used for beverages like ice tea.
Tea cream causes particular problems in production of instant tea for the US market, which is required to be of clear, bright appearance when reconstituted with cold water.
Tea cream: definition and processing of tea