Y2 EXPERIMENT STATION EECORD. [Vol.35 



ments were conducted to determine the value of different kinds of milli in the 

 manufacture of cheese. 



It was found that when the percentage of fat in the milk was increased, 

 other conditions being the same, the absolute as well as the relative loss of 

 fat in the whey was also increased, so that in the manufacture of cheese from 

 thin milk a larger percentage of fat goes into the cheese than when it is manu- 

 factured from richer milk. 



The poorer milk gives more cheese per pound of fat than does the richer. 

 The loss of fat in the whey can not be lowered by using warm milk immedi- 

 ately after milking, but the use of milk greatly chilled increases the loss to 

 a very small extent. The loss of fat in the whey is greater in the manufac- 

 ture of large-eyed cheese than in that with small eyes. 



The same relative quantity of nitrogen is lost in the whey regardless of the 

 nitrogen content of the milk. "When the content of nitrogen in the milk in- 

 creases the content of casein nitrogen is also increased, but this does not prove 

 a definite relation between the contents of casein nitrogen and total nitrogen. 

 Indol in cheese, V. E. Nelson (Jour. Biol. Chem., 2^ {1916), No. 4, pp. 533- 

 536). — In these studies, conducted at the Wisconsin Experiment Station, "indol 

 and phenol were found to be present in Limburger cheese. Skatol was not 

 found in Limburger cheese. Indol is present in handkUse. It is doubtful if 

 skatol and phenol are to be found in this type of cheese. A trace of indol is 

 present in Camembert cheese. Skatol and phenol are absent in this type of 

 cheese. Cheddar, Swiss, gammalost, brick, and Roquefort do not contain any 

 indol, skatol, or phenolic bodies. The amount of indol in a Limburger cheese 

 naturally varies, depending upon how far the ripening process has gone. A 

 young cheese may contain such a small amount that a quantitative estimation 

 is impossible, while a good ripe Limburger cheese may contain as much as 

 1 part in 52,800 parts of cheese. 



" Lactic and bulgaricus forms of organisms when grown upon media contain- 

 ing tryptophan produced no Indol or skatol. As growing organisms upon pure 

 amino acids is more difficult than upon proteins it may be necessary to add a 

 little peptone or milk to the culture, and until further work has been done upon 

 this phase it will be impossible to say that these organisms do not produce these 

 putrefactive substances. The liquefying coccus isolated from a Cheddar cheese 

 appears to produce traces of indol from tryptophan. If fhe experiments now in 

 progress confirm this statement, then the explanation why no indol is produced 

 by this type of organism in Cheddar cheese must be that conditions are 

 unfavorable and growth is suppressed." 



Study of the glycerin and lactic fermentation bacteria of cheese, Gekda 

 Teoili-Peteesson (Mcddel. Centralansi. Forsoksv. Jordbrnksomrddet, No. 10^ 

 (1915), pp. 15; K. Landtbr. Akad. Hundl. och Tidskr., 5^ (1915), No. 1, pp. 

 5M2).— The author states that three kinds of glycerin bacteria have been 

 discovered by her in Swedish cheese. These bacteria coagulate the milk but 

 do not form any eyes or gas bubbles. 



Experiments made with several kinds of cheese showed that Bactermm 

 I'lycerini (type c) forms, after long cultivation, gas in a lactose solution, while 

 before cultivation it does not do so. It does not cause hydrolysis of fat.' It is 

 found in the Swedish-Swiss cheese, as well as in the Gouda and the Westbot- 

 ten clioese (Vtisterbotten), and in greater quantity in the fresh cheeses than in 

 the older ones. No change of taste could be detected when the B. glycerini was 

 added to cheese milk under ordinary dairy conditions. 



Several varieties of lactic fermentation bacteria were isolated from the above- 

 mentioned cheeses, but no quantitative difference in these was detected The 

 number of B. acidi propionlci in cheese 11 months old with normal formation of 



