igii] Carl L. Aisberg 117 



The Brine-Soluble Compound Found in Cheese 



L. L. VAN SLYKE AND ALFRED W. BOSWORTH 



(Chemical Lahoratory, New York Agricultural Experiment Sta- 

 tion, Geneva, N. Y.) 



Investigations which have been conducted in this laboratory dur- 

 ing recent years have shown that in the ripening of cheddar cheese 

 a form of protein is always produced which is soluble in a 5 per 

 Cent, sodium chloride Solution. The presence of this brine-soluble 

 Compound was shown to be connected in some way with the de- 

 velopment of acid in the cheese. The Compound was at first erro- 

 neously supposed to be paracasein-monolactate and later free para- 

 casein. In recent work it was noticed that calcium was always to 

 be found associated with this brine-soluble Compound when it was 

 separated from the other cheese constituents by extraction with a 

 Solution of sodium chloride (c. p. — free from calcium), after first 

 removing the water-soluble constituents. 



This brine-soluble Compound is always present in cheddar cheese. 

 In a cheese two years old 40 per cent. of the nitrogen was present in 

 this form. It is also a fact that in cheddar cheese the calcium is 

 never completely extracted by water, part of it always being found 

 in the brine extract. In Camembert cheese, however, the reverse is 

 found. After the first few hours this cheese contains no brine- 

 soluble Compound and all the calcium is found in the water extract. 

 The brine-soluble Compound is formed in this cheese, but, owing to 

 the method of making, more acid is allowed to develop than in 

 cheddar cheese and, as a consequence, the brine-soluble Compound 

 loses its calcium and thereby becomes free paracasein, which is 

 insoluble in brine Solution. 



We believe that, according to the evidence in band, the follow- 

 ing equation represents the reaction which takes place where the 

 Compound in question is taken into Solution by a salt Solution : 



Calcium caseinate -\- 2 NaCl ^ Sodium caseinate -|- CaClg 



We believe that the mass action, thus represented, is also con- 

 nected with the precipitation produced upon adding calcium chloride 

 to the brine-soluble Compound after its Solution has been freed 

 from excess of chlorides by dialysis. 



