Volatile Carbonyl Compounds of Heated Green Tea (Hiire-cha)

Abstract

Volatile carbonyl compounds from heated tea (Hiire-cha) were separated by vacuum distillation and prepared as 2, 4-dinitrophenylhydrazones. Identifications of these compounds were carried out by means of G.C., T.L.C., and I.R.,
Ethanal, propanal, 2-methylpropanal, 2-methylbutanal, 3-methylbutanal and acetone were identified, and butanal, pentanal, hexanal and heptanal were presumed to exist.
The amounts of carbonyl compounds in heated tea increased by about twice that of unheated one. Especially, ethanal, 2-methylpropanal, 2-methylbutanal, 3-methylbutanal and acetone were produced remarkably.
From the quantitative analyses of free amino acids and reducing sugar in unheated green tea and heated one and also the model experiment in which amino acids and xylose were heated with green tea, it was supposed that volatile carbonyl compounds in heated tea might be produced by strecker degradation of free amino acids in green tea.