sensory properties of green tea and hypothesized that the
oxidation of flavanols (i.e. EGCG) during heat processing
and storage resulted in color development. Mizooku,
Yoshikawa, Tsuneyoshi, & Arakawa (2003) studied EGCG
oxidation as an effect of pH; EGCG was colorless in
aqueous solution at pH 7.6 however turned yellow at pH
10.6. Potential color problems could be reduced by
avoiding these color promoting conditions, by the use of
retardants or by optimizing the concentration of the
extract. The addition of vitamin C has been reported to
prevent green tea oxidation