268 The Fermentation of Cacao 



occurring during fermentation may be con- 

 sidered as being the brown colouration and 

 the reduction of the bitter taste of the nibs. 

 I am pleased to find that Loew, in explain- 

 ing this change, arrived in the main at the 



iO 



same conclusions that I did in my investiga- 

 tions undertaken a year later. There is one 

 point in which Loew's results differ from mine. 

 According to him the oxidase is insoluble, 

 whilst I have regarded it as soluble. In my 

 experiments I used an extract of fresh beans, 

 which were crushed under water so as to 

 delay oxidation. The filtrate was never clear, 

 and it is therefore possible that the substance 

 causinor the cloudiness contained the oxidase. 



O 



In order to clear up the divergence the follow- 

 ing experiment was made. Fifteen beans 

 were broken up in an atmosphere containing 

 carbonic acid and then covered with boiled 

 water. This was then filtered in a similar 

 atmosphere. The filtrate was at first cloudy, 

 but soon ran off clear. The clear, reddish- 

 violet solution gave a marked oxidase reaction. 

 Brought into contact with oxygen containing 

 air it soon turned brown and became clouded, 

 owing to precipitation of tannins. This brown 

 solution showed a very much weaker reaction 

 with oxidase reagents. If a few drops were 

 allowed to fall on blotting-paper and a solution 

 was added of, say, for instance, tetramethyl- 

 paraphenylen-diamin-hydrochloride, the most 

 marked blue reaction occurred in the centre,. 



