172 Report oF tHE CHEMIST OF THE 
destroying all enzymes and bacterial forms present in the milk. 
After cooling the milk te the temperature employed in cheese- 
making, chloroferm was added to the milk to the extent of 4 per 
ct. by volume in order to prevent any bacterial activity. As the 
ability of the milk-casein to coagulate with rennet is impaired by 
heat, this property was restored, in one case, by the addition of 
a smail amount of calcium chloride, and, in the other case, by 
passing a stream of carbon dioxide through the milk for half an 
hour. ‘The cheeses made from the milk thus treated were left in 
press over night, and were then examined at once for the salt- 
soluble product. The determination was made as follows: An 
amount of the fresh cheese, weighing 25 grams, was ground 
with sand and extracted with several portions of distilled water 
at 131° F. (55° C.) until the extract amounted to 500 cc. The 
residue was then similarly extracted with a 5 per ct. solution of 
sodium chloride. The amount of nitrogen in 50 cc. of this salt 
extract was determined by the Kjeldahl process. Table I gives 
the results obtained. The figures in parenthesis indicate the 
serial numbers of the different cheeses. | 
(2) With acid.— Other cheeses were made exactly like the pre- 
ceding. except that lactic acid was added to the milk to the extent 
of 0.2 per ct., by weight, of the milk. An examination of these 
cheeses, made at once after they were taken from press, gave 
the results stated in Table I. 
Tarte I.—AMmMouNT oF NITROGEN IN Saut-SoLtusBLeE Extract Os- 
TAINED FROM CHEESES MADE WITH AND witHout Lactic ACID. 


NirrRoGEN, ExprESSED AS PER- 
CENTAGE OF ToTAL NITROGEN 
IN CHEESE. 
NirrRoGEn EXxprESsED AS PER- 
| CENTAGE OF CHEESE. 


Made with addi-| Made with addi- ||Made with addi-| Made with addi- 
tion of calcium tion of carbon tion of calcium tion of carbon 
chloride. dioxide. chloride. dioxide, 

(1) With acid.....| 27.88 (45) | 29.80 (48) || 0.87°(45) | 0.700 (48) 
With acid.....| 26.62 (46) | 22.90 (51) || 0.84 (46) | 0.754 (51) 
(2) Without acid..] 2.44 (44) | 5.24 (49) | 0.76 (44) | 0.132 (49) 
Without acid..| 2.90 (47) | 5.72 (50) || 0.76 (47) | 0.148 (50) 






ee 
