EXPERIMENT STATION BULLETINS. 



489 



THE INFLUENCE OF FREEZING ON THE BACTERIAL CONTENT OF THE ICE 



CREAM MIX 



After the ice cream mix liais aged 24 hours it was ^hen frozen in 80 

 quart Miller freezers. The temperature of the brine at ■wihich the mix is 

 frozen ranges from —15.5° C (4° F) to —12.2° C (10° F) with an average 

 of — 14° C (7° F), The samples were collected just as the material was 

 leaving the freezers. The influence of this process is given in Table VI. 



Table VI. — Showing Bacterial Count Before and After Freezing 



The resailts dn TaMe Vl is'how that in 46.34 per cent of the samples 

 there was an increase ranging from 0.95 per cent to 260.00 per cent with 

 an average increase of 46.47 per cent. In 36.58 per cent of the samples 

 there was a decrease ranging from 3.85 per cent to 59.68 per cent with an 

 average of 25.95 per cent decrease while in 17.07 per cent of the samples 

 there was no change. The increase in the number of 'Colonies is no doubt 

 due largely to the breaking up of clumps of bacteria. Many chimps w(hich 

 ordinarily would produce one colony are presumably broken up into se\'- 

 •eral chimps or single cells each of which may produce a colony. The in- 



