New York Agricultural Experiment Station. 209 



Effect of chloroform on the action of rennet-cnsymc in cheese- 

 ripening.- — We have already called attention to the point that a 

 comparison of the results contained in Tables III and V suggests 

 that chloroform may exert some retarding influence upon the 

 action of rennet-enzyme in cheese-ripening. In Bulletin No. 203, 

 page 224, we published some results which appeared to indicate 

 that chloroform has little or no effect upon galactase, but those 

 results do not necessarily apply to any other enzyme. The work 

 of Malfitano, already referred to, indicates that the action of a 

 peptic ferment is retarded by chloroform. 



DISCUSSION OF RESULTS. 



In the work described in the preceding pages, we have studied 

 the proteolytic action of rennet-enzyme under the following 

 conditions: 



(i) /// cheese containing rennet-encvnie as the only proteolytic 

 agent, luith and zvithout acid, and also zvith and zvitJiout salt. — In 

 these experiments (44 to 51), all milk-enzymes were destroyed 

 by heating at 95° C. to 98° C. (203° F. to 208° F.), the coagu- 

 lable property of the milk-casein was restored by the addition of 

 either calcium chloride or carbon dioxide gas, and all organisms 

 were rendered inactive by chloroform. Acid, when present, was 

 furnished by addition of pure lactic acid. 



(2) /;/ cheese containing rennet-cncyine together tvith acid-forming 

 and sonic proteolytic organisms. — In these experiments (52 and 53), 

 the milk enzymes were destroyed bv heating, acid was furnished 

 by a lactic-acid " starter," but no chloroform was used. We thus 

 had, as our only proteolytic agents, rennet-enzyme in the presence 

 of acid and same liquefying organisms that were introduced in 

 the " starter " or that got into the milk or curd during the opera- 

 tion of cheese-making. 



(3) /// cheese containing commercial pepsin in addition to rcnncf- 

 encyme, together zvith hydrochloric acid and such organisms as zvere 

 introduced during the process of making cheese. — In these experi- 

 ments (55 to 57), the milk enzymes were destroyed by heat and 

 commercial pepsin added in different amounts. 



(4) 1)1 comparison zvith commercial pepsin on casein in milk, zvitli 

 and zvithout acid. — In these experiments, the milk-enzymes were 



