EXPERIMENT STATION BULLETINS. 



537 



TABLE I.-DATA OBTAINED FROM TWELVE CHURNINGS.— Conduded. 



*These numbers represent thousands per gram. 



TABLE 2.- AVERAGE OF DATA OBTAINED FROM TWELVE CHURNINGS. 



TEROXIDASE AND REDUCTASE IN CREAM AND BUTTER. 



When the various samples were analyzed, tests were made for the 

 presence of the enzymes peroxidase and reductase. The data recorded in 

 Table II show that these enzymes reacted negatively when starter, rip- 

 ened cream or butter milk was the sample in question. The unripened 

 cream and the butter manufactured therefrom reacted positive. Their 

 presence in the butter indicate that they were not destroyed but rather 

 that they were inactivated during the ripening process. As the differ- 

 ence between the unripened and ripened cream is manifested in the 

 acidity, samples of cream which react positive for both of these enzymes 

 were made 0.55 percent acid by adding N/1 lactic acid; these acidified 

 samples reacted negative, but upon reducing the acidity of duplicate 

 samples by the addition of N/1 sodium hydroxid positive tests were ob- 



