Cream formation in a semifermented tea
Journal
Journal of the Science of Food and Agriculture
Journal Volume
79
Journal Issue
13
Pages
1767-1774
Date Issued
1999
Author(s)
Chao Y.C.
Abstract
The formation of cream in Paochung tea, a popular semifermented tea, which undergoes a lesser degree of enzymic oxidation during manufacture, was investigated at various extraction temperatures, extraction times, pHs and leaf/water ratios. The primary components of Paochung tea cream were catechins (30%), caffeine (20%) and protein (16%). (-)-Epigallocatechin gallate and (-)-epicatechin gallate were the major catechins precipitated during creaming, constituting 19% and 5% of the tea cream respectively. The amount of tea cream produced and its composition were influenced by extraction temperature and pH. The tea leaf/water ratio determined the amount of tea cream formed but did not affect the cream composition. Catechins were considered to be the key component in tea cream. They interacted with caffeine and protein to induce tea cream formation.
Subjects
Catechins
Cream
Paochung tea
Semifermented tea
Type
journal article