77G EXPEKIMENT STATION KECORD. 



liliK'. I'astcurlzod milk iiiofulated witli the orK<iiii!*ni d('Vol«>jie(l a more intense 

 folor than slerilized milk, and in some Ciises (apitarently inflnenced largely by 

 tlie oi-f^anisms snrvivinj; iKislcnrization) the color developed approximated that 

 deveUtped in raw nulk. It was noticed that pasteurized milk which curdled 

 quite rapidly, due to the production of a<U\, j;ave a j^ood color development as 

 a rule. In .sterilized lidlk the color production was poor and is best desc-ribed 

 as a bluish gray rather than as a blue. In milk to which ;;lucose was added 

 before sterilization the color produced was more intense than in ordinary 

 milk." 



An increase in the intensity of the color was accompanied by an increase in 

 acidity. The addition of liavtcrium lactis acUU to milk cultures of the blue milk 

 or;;anism (either freshly inoculated or a number of days old | resuUed in a great 

 increase in the intensity of the color. 



" In no case was it possible to produce a blue color in milk held at 37° C. 

 [08.0° F.], no matter what the previous treatment of the milk had been. The 

 same temperature influence was found to hold for the various bouillons and it 

 .seems that the higher temperatures are unfavorable to the production of color. 

 No attempt was made to determine the lowest temperature which would pre- 

 vent the forniation of color. 1)ut both room temperature and 20° allowed the 

 rapid production of color." 



I'asteurlzation as well as sterilization favored the production of color uni- 

 forml.\ throughout the sample, while in raw milk the color was in the main 

 I»resent only at the surface. Color production was found to occur in skim milk, 

 in whole milk, and in cream, and in all cases the color production was greatest 

 at and near the surface in the raw material. Attempts to ]>roduce a blue color 

 in pieces of old cheese by the inoculation of the organism from agar slopes 

 were unsuccessful. 



A historical sketch of investigations of this organism is given, together with 

 a bibliography of 12 references. 



Tlie use of Bacillus bulgaricus in starters for miaking Swiss or Emmental 

 cheese, C. F. I)o.\ne and H E. Eldredge ilL ,S'. Dept. A<jr. Bui. L'fS (IfHo). pp. 

 16, pi. 1, fig. 1).- — This bulletin reports experimental work showing how to con- 

 trol undesirable fermentations and thus to jirovide a remedy for the most serious 

 troubles which occur in making Swiss or Emmental cheese. 



Many cultures of B. hnlgaricufi obtained from different sources were u.sed 

 and found to vary widely in their ability to suppress gas-forming bacteria, some 

 I)roving efficient when the starter was less than 2 iier cent of the total amount 

 <tf milk used, whereas other cultures were not efficient with less than 4 i»er 

 cent. Ordinary lactic acid cultures were not successful in i)reventing gas 

 formation. Experiments with B. huhjaricus starters in a conmiercial factory 

 demonstrated that the maker of Swiss cheese can control the fermentations 

 with some cultures of this organism ; that a good quality of Swiss cheese can 

 be made in winter as well as in summer ; and that it is probably practicable to 

 make cheese once a day instead of twice a day. as has been necessary in the 

 past. 



Methods are described for preparing and keepiujr cultures, and a new tyi)e of 

 starter-can for carrying starter is illustrated and described. This starter-can 

 may be used for other dairy purixises with whey starters. 



Influence of the flora of the cheese I'ind on the proteolysis and fat-splitting 

 in the inner portion of the cheese, O. Gratz and I. Szanyi (KUcrJci. Knzleni.. 

 ft (1914). No. 5. pp. 801-83.'/, figs. 16). — From analyses of different portions of 

 the cheese it was concluded that the flora of the outer portion do not participate 

 In the proteolysis and fat-sjilitting of the inner iiortion. 



