176 EXPEEIMENT STATION EECOED. 



Gathered cream for butter making, J. A. Ruddick and G. H. Barr {Canada 

 Dept. .l;/r.. Branch Dairy and Cold Storat/e Comr. Bill. 1o, pp. 12, fifjs. .3). — Sug- 

 gestions are made concernins: the pi-(>])er handling and care of cream intendetj 

 for factory butter mailing. 



Some of the first chemical changes in Cheddar cheese, L. L. Van Slyke 

 and A. W. Kosworth {\eir York >^tatr .S7rt. Tecli. Bid. //. jip. l-IG). — The 

 authors studied the early changes taking place in the proteids of cheese and 

 also changes in the calcium and phosphoric-acid compounds. 



" Five cheeses were made at different times under the usual conditions ob- 

 served in making Cheddar cheese. They were kept at 15.5° C. Determinations 

 in cheese were made of the amounts of (1) total nitrogen, (2) nitrogen soluhle 

 at 55° C. in 5 per cent solution of sodium chlorid. (3) water-soluble nitrogen, 

 (4) acidity of water-extract, (5) lactose, (G) total calcium and phosphoric- 

 acid compounds. (7) water-soluble calcium and phosphoric-acid compcmnds. (8) 

 calcium compoimds in the salt-soluble ])ortion. (0) calcium lactate. (10) total 

 and water-soluble ash. . . . 



" (1) The insoluble proteid of fresh choese-curd (calciinn paracasein) changes 

 rapidl.v into a form soluble in 5 per cent solution of sodium chlorid at 55° C, 

 until, in 9 or 10 houi's after the cheese is put in press, the proteid. originally 

 insoluble in the salt solution, becomes completely soluble in this solution. (2) 

 Then the proteid soluble in salt solution changes into a form insoluble in salt 

 solution, this change taking place rapidly at first and then gradually. (3) 

 Proteids in water-soluble form appear to increase only slightly, if at all. until 

 after the salt-soluble proteid has partially changed into the form insoluble in 

 salt solution. . . . 



"The calcium and phosphoric-acid compounds of cheese, insoluble at the 

 start, become soluble luitil about 80 per cent of the calcium and all of the phos- 

 phates become soluble in water. This change is due to the formation of lactic 

 acid and its action upon the phosphates of the cheese, resulting in the formation 

 of monocalcium phosphate and calcium lactate. About 20 per cent of all the 

 calcium in the cheese is found in the siilt-soluble portion, and the proteid in 

 this solution shows :\n acidity aliout equal to tliat shown by calcium paracasein." 



The acidity of the water extract of Cheddar cheese, L. L. Van Slyke and 

 A. W. Bosworth (Xeic York .Sfo/c »S'/ff. Tech. Bill. J,, pp. 17-22) .—The acidity 

 of the water extract of normal Cheddar cheese is attributed to monocalcium 

 phosphate. 



Chemical studies of Camembert cheese, A. W. Bosworth (Neiv York State 

 Sta. Tech. Bui. 5. pp. 23-39). — The Imlletin is summarized by the author as 

 follows : 



"Camembert cheese can be made in the laboratory which compai-es very 

 closely to the cheeses found upon the American market, to the cheeses imported 

 from Europe, and to those worked upon by other investigators. 



" The only function of the rennet in this type of cheese is to coagulate the 

 milk. 



"The bacteria are responsible for the most important chemical changes 

 which take place In the cheese during its early history. 



" The changes caused by the bacteria, directly or indirectly, are as follows : 



"(a) Lactic acid is produced from milk sugar. 



"(b) This acid as formed combines with some of the insoluble calcium which 

 is present in a new cheese as phosiihates and as calcium paracasein. 



"(c) The lactic acid in combining with some of the calcium of the insoluble 

 phosiihates produces calcium lactate and soluble phosphates. These soluble 

 phosphates are acid salts and increase the acidity of the cheese. 



