RoLE OF OXYDASE IN THE PREPARATION OF TEA. 259 



I. The black color of the commercial black tea is produced 

 by the action of oxidase upon tannin. 



II. The green variety of the commercial tea owes its green 

 color to the destruction of oxidase in the first steps of preparation. 



III. By the final steps of its preparation, the black tea also 

 loses the oxidizing enzyme. 



IV. In tea leaves occur proteids containing iron and 

 manganese. 



In 100 parts of dry matter, 



N 



Fe 



M11 



8.66 



0.18 



no reaction. 



SUMMARY. 



