162 



H. H. Mann — The Enzymes of the Tea Leaf. 



[No. 2, 



In eacb case tbe tip leaf is regarded as nnifcy, and eacli is calculated 

 on the dry matter. The acidity due to the tannin in each case amounted 

 to about half the total acidity, using phenol phthalein as indicator, and 

 appeared to be practically identical (on the dry matter) throughout the 

 flushing shoot. The enzyme therefore appears not to bear any very 

 close relationship to any of these constituents calculated as above, if the 

 stalk bo included, but if this be left out (as I think it may be, for it is 

 to a great extent nothing but a channel of conveyance), then the enzyme 

 will be found to follow both the Tannin and the Phosphoric Acid, but 

 not the acidity, except that caused by the tannic acid. 



The practical consideration now comes in as to the relpvtion of this 

 enzyme to quality in tea. The only means of ascertaining this was to 

 compare the leaf from gardens lying near one another producing dis- 

 tinctly different types of tea, and teas which were regarded by experts 

 as of different quality. It is necessary, of course, in face of the distri- 

 bution of the enzyme in the flushing shoot above pointed out, that the 

 leaf shall be of approximately the same type. For instance, a stalky tea 

 eaf could not in any sort of fashion be compared with one giving little 

 stalk. With this reservation, which was taken into account in the experi- 

 ments which follow, the figures obtained seem to indicate that a large 

 amount of ferment means a high quality tea, and a reduction in the 

 enzyme present means a lowering of the flavour of the product. It is in 

 the flavour that the effect is most marked, the strength of the tea being 

 not nearly so much affected. 



Three gardens are concerned in what follows. ' These are A, which, 

 judged by market prices, has been making a medium Darjeeling tea • 

 B, which has had the reputation of making about the best tea in the 

 Darjeeling district for many years, and C, which has produced absolutely 

 the highest value teas in the district during the past season. 



A comparison was first made between a sample of leaf from A and 

 two samples from bushes of different types from C, No 1 being an 

 "Assam " type of plant, and No. 2 from a " China" type. The following 

 figures were obtained : — 







Relative amount of active 



Relative total amount of 







enzyme. 



enzyme. 





A. 



1-00 



1-00 



C. No. 1. 



... 



217 



218 



C- No. 2. 



... 



1.44 



1-68 



