The roles of catechins and caffeine in cream formation in a semi-fermented tea

The mechanism of cream formation in a semi-fermented tea was investigated by adding caffeine or catechins to the de-creamed tea infusions. The addition of catechins to the clarified infusion could not re-induce cream formation. However, creaming occurred again after replenishing the de-creamed tea infusion with caffeine. It was thought that the ester-form catechins which possessed a galloyl group and a hydroxylphenyl B ring acted like a claw. They could thus entrap and interact with caffeine more effectively through hydrogen bonding and hydrophobic interaction to form a large complex, resulting in creaming. © 1999 Society of Chemical Industry