These authors found that when green
tea extract was incorporated to edible coatings (based on tapioca
starch/decolorized hsian-tsao leaf gum), an antimicrobial activity
on Gram-positive bacteria was also found since the active compounds
could migrate from the coating and increase the inhibition
area. Thus, the green tea extracts may inhibit the growth of both
Gram-negative and Gram-positive bacteria, but this effect is highly
dependent on the species being tested.