3 = ae 
Rev .ed * 
follows 
BULLETIN No. 342 
Washington, D. C. Issued January 8, 1916; revised October 10, 1922 
THE PRESENT STATUS OF THE "ASTAURIZATION. 
OF MILK. i ‘ ; > & V 
399 
By S. Henry AYERS, te} NO Va i¥2Z 
Bacteriologist, Dairy Division, Bureau of, Aqinal Jydustw.« aghoultere 
errr ey eer Se Lk 
CONTENTS. 
Page. Page 
Meaning of the term pasteurization_ 1 | Handling milk after pasteurization_ 15 
Valse of  Pasreuriza tion <— | -_-_ 2 | Cost of pasteurizing milk. 2. 16 
Electrical and ultra-violet-ray treat- Bacteria which survive pasteuriza- 
OVE Tc RCO) 1k ee ee ee 4 OW Sod Fen Aes Gee ge SGA OS 16 
Extent of pasteurization in the The colon test for efficiency of pas- 
Limnbed Esietlesee et Se ee SS TT ye Hi) teurizalion 22722 <3 Sey. See 20 
Methods of pasteurization________~- 7 | Past and present theories of aataae 
Advantages of low-temperature pas- PZE OI OG a es ee 20 
‘Males hintyi es ree eee eee eee a 10 | Pasteurization and vitamins_______ 22 
Temperatures and methods most suit- The necessity for pasteurigation____ 24 
able for pasteurization__________ aft | References to literature___________ 25 
Supervision of the process___-______ 13 
MEANING OF THE TERM PASTEURIZATION. 
The term “pasteurization” originated from the experiments of 
Louis Pasteur, in France. From 1860 to 1864, in experiments on the 
“diseases” of wine, he found that heating for a few moments at 
temperatures of from 122° to 140° F. was sufficient to prevent abnor- 
mal fermentations and souring in wine. A little later he found 
that by a similar heating beer could be preserved from souring. 
The applicaticn of the process gave rise to the term “ pasteurization.” 
As applied under commercial conditions, pasteurization is the process 
of heating for a short or a long period, as the different processes 
demand, at temperatures usually between 140° and 185° F. As ap- 
plied: to milk for direct consumption, pasteurization should mean 
a process of heating to 145° F. and holding at that temperature for 
30 minutes. The process is followed by rapid cooling. 
Jt is believed that the term pasteurization should be applied only 
to. the process of heating at 145° F’. for a period of 30 minutes. 
107148°—22—__1 
