256 Report of the Chemical Department of the 



ing and that there was a more rapid increase in the formation of 

 total water-soluble nitrogen compounds, especially of amides and 

 ammonia, than in the smaller cheeses. 



THE RELATION OF SALT IN CHEESE TO CHEESE- 

 RIPENING. 



In Bulletin No. 203 of this Station, page 241, attention is called 

 to the fact that salt exerts a retarding influence upon the pro- 

 teolytic action of enzymes in cheese. Since the results given 

 there were secitred with cheese made and kept in the presence of 

 chloroform, it was desired to make a study of the influence of salt 

 upon the ripening process in cheese normally made and kept 

 under normal conditions. For the purpose of such a study, 6 

 dififerent lots of cheese were made under normal conditions as 

 nearly alike as possible. In each lot there were 4 to 8 cheeses, 

 weighing 10 or 30 pounds each and salt was added to these in 

 proportions varying as follows: no salt, 1.5, 2.5, and 5 pounds of 

 salt for 1000 pounds of milk. During the ripening i lot was kept 

 at 32° F., 3 at 55° F., i at 60° F. and i at 70° F. The detailed 

 analytical results are given separately for each lot of cheese in 

 the Appendix. In Table V we give the averages of the 4 lots of 

 larger cheeses kept at the different temperatures. Whether we 

 consider each lot of cheeses by itself or their averages, the result^ 

 are strikingly concordant in respect to the effect of salt upon the 

 formation of nitrogen compounds in the ripening process. 



It has been a fact long observed by cheesemakers that increase 

 of salt in cheese delays the rapidity with which the cheese be- 

 comes marketable, but no detailed chemical study has previously 

 been made of the subject in this country. Decker^ made a brief 

 study of the influence of varying amounts of salt upon normal 

 Cheddar cheese in respect to texture, flavor and moisture, but the 

 study was continued only one month and no attention was given 

 to the products of proteolysis. 



We are to regard the salt in cheese as being in solution in the 

 whey held. by the cheese, practically forming a dilute brine. In 

 common practice, cheesemakers add from 2 to 2^ pounds of salt 

 to the curd made from 1000 pounds of milk. Cheese thus salted 

 contains about i per ct. of salt. Such cheese usually contains 



1 Ann. Kept. Wis. Exp. Sta. 11: 220 (1S94). 



