Preserving Milk with Chemicals. ^99 



At that the additions do not accomplish the purpose for which 

 they are intended in the dilutions in which they are used (Richter- 

 boracic acid), or they diminish the utilization of milk for cheese 

 production because they inhibit the rennet action. Soda or bi-car- 

 bonate of soda, boracic acid and borax, more rarely salycilic acid, 

 and recently formaldehyde are mostly used. Adulterations will 

 not be discussed here, but only earnest scientific experiments will 

 be taken up, in which the accomplishment of an actual improve- 

 ment in milk has been the object sought. 



1. Budde succeeded in improving the keeping qualities of 

 milk with the aid of peroxide of hydrogen. The milk is heated to 

 about 50 deg. C., 0.036 to 0.5% H 2 2 is added and it is then filled 

 into bottles and kept for several hours at 50 deg. C. 



According to Lukin it is possible with pure peroxide of 

 hydrogen, as indicated by Budde, to give the milk a low bacterial 

 count, or render it free of bacteria. Budde 's method has not at- 

 tained an extensive use. According to Chick, Eosam, Gordan, 

 Bergmann and Hultmann, Eicholz, Nikoll and Duclaux the amount 

 of peroxide of hydrogen recommended by Budde is not sufficient 

 for the satisfactory destruction of bacteria in milk, but according 

 to Lukin their failures were due to the use of impure preparations 

 of peroxide of hydrogen. Tubercle bacilli and typhoid bacilli 

 were not destroyed by this method. If the authors used 0.1% of 

 peroxide of hydrogen, the necessary quantity to produce steriliza- 

 tion, then the milk obtained a bitter taste, which disappeared only 

 after the excess of hydrogen peroxide had been eliminated by cat- 

 alase. According to IJtz a small quantity of peroxide of hydrogen 

 is retained in the milk even when used in the quantities recom- 

 mended by Budde. De Waele, Sugg and Vandevelde, who worked 

 with 0.3 and 0.4% of peroxide of hydrogen, have used in addi- 

 tion small quantities of defibrinated blood for splitting up the 

 retained H 2 2 . 



Much and Rb'mer employ a similar method of preserving milk 

 which has been obtained under special precautions as to cleanli- 

 ness. The milk is filled into sterilized bottles, mixed with 0.1% 

 of peroxide of hydrogen, and kept for one hour at 52 deg. C. 

 For the destruction of the H 2 2 in the milk, hepin, a catalase 

 prepared from liver, is added to the milk before its consump- 

 tion. Since the hydrogen peroxide milk is very sensitive against 

 the influence of light (when exposed to light it very readily be- 

 comes bitter, tallowy and rancid), it is best to keep it in green 

 bottles and in a dark place. Even with these precautions a change 

 in the taste may become apparent after two weeks. 



Injurious action of the peroxide of hydrogen if used in these 

 quantities should not be feared; the results in infant feeding are 

 supposed to be favorable. 



The milk which is freed from the retained peroxide of hydro- 

 gen by the addition of hepin should be immediately used, since it 



