On the Chemical Changes of the Tea Components in the Manufacture of Black Tea (Continued)

Abstract

1. As the results of study by paper chromatography and nepherometric estimation of catechins, it was reccgnized that almost all of catechins in the fresh tea leaves were oxidized during the manufacture of black tea, and there contained little as unoxidized form in the made tea of the 2nd and 3rd crops, while a pretty amount of catechins remained unoxidized in the tea of the 1st crop.2. Four spots of anthocyans were, for the most part, decomposed throughout the manufacture.3. Considerable differences in the chemical changes of amino acids between the 1st crop and the other crops, 2nd and 3rd, were obs-erved. Throughout the manufacture of black tea, in general, a remarkable increase of asparagine and decrease of theanine were observed.