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

The mechanism of cream formation in a semi-fermented tea was investigated b y adding caffeine or catechins to the de-creamed tea infusions. The additio n of catechins to the clarified infusion could not re-induce cream formatio n. However, creaming occurred again after replenishing the de-creamed tea i nfusion with caffeine. It was thought that the ester-form catechins which p ossessed a galloyl group and a hydroxylphenyl B ring acted like a claw. The y could thus entrap and interact with caffeine more effectively through hyd rogen bonding and hydrophobic interaction to form a large complex, resultin g in creaming. (C) 1999 Society of Chemical Industry.