DAIRY FARMING DAIRYING. 



289 



Having defined the part which the peptonizing bacteria play in the 

 ripening of cheese, the question still remains unsettled whether these 

 bacteria which are, according to Freudenreich, present in hard cheese 

 in small numbers, act as such in the process of ripening or by means 

 of a diastase secreted by them at the beginning of the process. The 

 author states that experiments made by him have shown that the dias- 

 tase in question, named by Duclaux casease, acts just as energetically 

 in the absence of the bacteria by which it is secreted as in their pres- 

 ence. From this it would follow that if casease is a factor in the ripen- 

 ing of cheese it would have to be present only in a small quantity.— P. 



FIREMAN. 



On the ripening of cheese, O. Jensen (TidssJcr.for Fysik og Eemi, 

 2(1897), pp. 92-114; abs. in Centbl. agr. Ghem., 26, No. 10, p. 707).— 

 The author claims that in the ripening of cheese the caseinous matter is 

 partially peptonized and rendered soluble by meansof an enzym, casease, 

 very similar to trypsin; that the microorganisms typical of cheese "fer- 

 mentation" are more indirect than direct in their action; and that the 

 cheese "fermentation" is probably not to be regarded as a true fermen- 

 tation. He reports some experiments in ripening cheese with the aid 

 of trypsin, as casease can not easily be obtained in large quantities. 

 Experimental cheeses were made with skim milk pasteurized and unpas- 

 teurized. Into half the curd 20 cc. of pancreas was kneaded before 

 putting to press. Ether was added to prevent the action of bacteria. 

 It was found by analysis that the cheese made with pancreas contained 

 nearly 50 per cent more soluble nitrogen than cheese made without the 

 addition of pancreas. 



Other experiments were made on a large scale at an estate. For 

 several successive days 2 cheeses were made with the addition of pan- 

 creas (\ liter and J liter per cheese) and 2 without. The cheese made 

 with pancreas had the appearance of being much fatter than the 

 control cheese. Analysis showed the following with reference to the 

 nitrogen : 



Soluble nitrogen in cured cheese. 



It is evident that the addition of pancreas increased the peptonizing 

 in proportion to the amount of pancreas added. The total amount of 

 soluble nitrogen was also increased, while the ammonia was slightly 

 decreased. It was demonstrated that the soluble protein consisted, in 



