Bacteria in the Cheese Industry. 181 



Development of mold invariably takes place in a moist 

 atmosphere, either at high or low curing temperatures. 

 These are frequently the conditions that are required 

 in curing certain types of hard American cheese, so that 

 mold is apt to appear. 



The use of a double bandage or rubbing the cheese 

 when ready for market will remove this blemish. Recent 

 experiments with certain disinfectants like formalin show 

 that SL 2 % solution rubbed over surface will retard the 

 development of mold. 



190. Poisonous cheese. The production of poison- 

 ous ptomaines in cheese is perhaps more common than 

 with almost any other food product. Vaughan 1 to whom 

 the most of the work on this subject is to be credited, 

 reports over 300 cases of cheese-poisoning in two years. 

 It seems to be very much more common here in America 

 than it is in Europe. Vaughan has isolated from numer- 

 ous samples a highly poisonous alkaloid that he calls 

 tyrotoxicon. This ptomaine has also been frequently 

 demonstrated in milk, cream, and ice cream. The poi- 

 sonous substances formed in the milk are probably pro- 

 duced through the agency of putrefactive organisms that 

 gain access to the milk. 



The poisons secreted in the milk are transferred to the 

 cheese with their virulence often unimpaired, so that seri- 

 ous complications follow where the infected material is 

 used for human food. Vaughan states that cheese which 

 reddens litmus paper rapidly should be regarded as sus- 

 picious. In normal cheese, this reaction occurs very 

 slowly. Danger from this source is to be noted particu- 

 larly with the so-called sour milk cheese; as the methods 

 by which these are made give the most favorable oppor- 



1 Vaughan, Zeit. f. physiol. Chemie, 10: 146. 



