8 BULLETIN 563, U. S. DEPARTMENT OF AGEICULTUBE 



Table II. — Variation in bacterial content of 9 duplicate samples from each of twenty-tioo 

 1 -gallon lots of commercial ice cream. 



Plant 

 No. 



Lot. 



Flavor. 



Bacteria per cubic 

 centimeter. 



Varia- 

 tion in 

 bacterial 

 count. 



Minimum. 



Maximum. 



1 





Vanilla 



Chocolate . . . 

 Peach 



Vanilla 



2,085,000 



445,000 



1,460,000 



20,000 



7,150 



2,530,000 

 585,000 



1,600,000 

 80,000 

 13,000 



Per cent. 



21.34 



31.46 



9.59 



300.00 



81.81 



B : : 



C 



D 



E 





2 



A 



Chocolate . . . 

 Vanilla 



43,500,000 

 180,500,000 

 60,000,000 



61,000,000 

 225,000,000 

 75,000,000 



40.23 

 24.65 

 25.00 



B 



C (fat, 9.6 per cent) 





3 





Chocolate . . . 



251,500 

 192,000 

 975,000 



307,000 



221,000 



1,235,000 



22.31 

 15.10 

 26.66 



B 



C 





4 



A (fat, 22 5 per cent) . 



Vanilla 



Peach 



Chocolate . . . 



27,000,000 

 28,750,000 

 28,000,000 



33,750,000 

 47,000,000 

 33,000,000 



25.00 

 63.47 

 17.85 



B 



C 





5 





Vanilla 



Peach 



Chocolate . . . 



335,000 



410,000 



122,000,000 



490,000 



500,000 



160,500,000 



46.27 

 21.95 

 31.55 



B 



C 





6 





Peach 



Chocolate... 



13,150,000 



97,000,000 



37,000,000 



1,055,000 



27,000,000 



116,000,000 



46,500,000 



1, 415, 000 



105. 32 

 19.59 

 25.67 

 34.12 



B 



C 



D 





7 



A 



Chocolate . . . 



1,310,000 



1,770,000 



35. li 





VARIATION WHEN HELD IN AN ICE-CREAM CABINET. 



It was thought that there might be an uneven distribution of 

 bacteria in ice cream held hi an ice-cream cabinet where it is allowed 

 to soften, then is repacked with ice and salt and again hardened. 

 To determine this point, three 1 -gallon lots of ice cream were pur- 

 chased from three different manufacturers and held for 11 days in a 

 commercial ice-cream cabinet, such as is used in stores. 



The ice cream was packed with ice and salt once a day in the 

 regular way. From day to day it softened and again hardened. 

 In Table III it may be seen that even under this extreme condition 

 the highest variation among the samples from each lot was only 

 37.03 per cent. In this case the lowest count was 1,080,000 and the 

 highest 1,420,000 per cubic centimeter. 



