The American Journal of Public Health 



TABLE OF CONTENTS 



L Introduction 2 



il. The Present Status of Milk Pasteurization 2 



(1) Number of Plants in Operation 2 



(2) State, Territorial and Provincial Control 2 



(3) Municipal Control ^ 2 



(4) Definitions of Pasteurization 3 



(5) Apparent Lack of Control and Uniformity of Methods 3 



(6) Absence of Public Understanding of Pasteurization 3 



HI. The Efifect of Pasteurization on the Composition of Milk 3 



(1) Effect of Heat on Milk 4 



(3) Infant Feeding Experiments 4 



(3) Infant Feeding vs. Communicable Disease 5 



IV. The Process of Milk Pasteurization ! 6 



(1) Holding System Required 6 



(2) Pasteurization Process Defined ■. 6 



V. The Mechanical Features and the Operation of Pasteurization Plants 7 



(1) Methods of Pasteurization 7 



(.2) Pasteurization in the Bottle _ 7 



(3) Pasteurization with Intermittent and Continuous Flow Apparatus.. 8 



(a) Flow Controllers 8 



(b) Heaters 8 



(c) Holders 9 



(d) Coolers 10 



(e) Pumps 11 



(f) Stuffing Boxes 11 



( g) Fittings and Valves 11 



(h) Metals Used in Construction of Apparatus 11 



(i) Temperature Control Apparatus 11 



(j) Temperature Recording Instruments and the Interpretation of 



Recording Charts 13 



(k) Cleaning and Sterilizing Apparatus 14 



(4) Some Dangerous Defects in Pasteurization Apparatus ]"< 



VI. Analytical Control of Pasteurization Plants 16 



(1) Physical Methods 16 



(a) Testing of Time and Temperature Recording Devices 16 



(2) Chemical Methods 17 



(3) Physico-Chemical Methods 17 



(4) Biological Methods 17 



(a) Biological Demonstration of Efficiency Procedure .A. ir 



(b) Biological Demonstration of Efficiency Procedure B 19 



(c) Biological Demonstration of Efficiency Procedure C... 30 



(d) Application of Tests to Demonstrate Efficiency 34 



(.5) Conclusions on the Analytical Control of Pasteurization Plants 2.j 



VII. State and Municipal Supervision of the Pasteurization of Milk 36 



(1 ) Time and Temperature Requirements 2G 



(3) Department to Control Pasteurization '. 27 



(3) Requirements Regarding Apparatus 27 



(■J ) Qualifications of Plant Operators 28 



('}) Bacterial Results on Pasteurization 28 



(6) Penalties for Violations 28 



Vill. Summary 30 



