Production of a New Type Tea Containing a High Level of ϒ-Aminobutyric Acid

Abstract

The tea leaf content of ϒ-aminobutyric acid and alanine increased after leaf incubation in nitrogen or carbon dioxide gas, whereas theanine, caffeine and tannin showed little change. The level of ϒ-aminobutyric acid in green tea made from tea leaves incubated in nitrogen gas for 6 hr was higher than 150mg/100g. The levels of ϒ-aminobutyric acid in oolong tea and black tea made from withered tea leaves incubated in nitrogen gas were higher than in tea made from leaves incubated in nitrogen gas before withering. Although the contents of ethyl palmitate, methyl linoleate, ethyl linoleate, methyl linolenate and ethyl linolenate in the tea made from leaves incubated in nitrogen gas were higher than those in tea made from non-treated leaves, the aroma of these compounds was not the predominant aroma of this new type of tea.