512 THE PASTEURIZATION OF MILK 



6. Does this method furnish absolutely accurate values? If not, why not? 



7. Describe in detail the method of estimating the acidity of cow's milk. 



8. How are the results of bacterial counts rounded off when recording the 

 results of bacterial milk examinations ? 



9. How are bacterial counts of certified milk expressed ? 



10. What is certified milk? 



11. Give in outline the rules under which certified milk should be produced. 



12. What are the duties of the veterinarian in connection with the production 

 of certified milk? 



13. Where does the term pasteurization come from? 



14. Give a definition of it. 



15. What is the difference between sterilization and pasteurization? 



16. What is the difference between continuous and discontinuous pasteuri- 

 zation? 



17. What are the four objects of the pasteurization of milk? 



18. What exposures to heat are necessary to kill tubercle bacilli in milk? 



19. Under what conditions are tubercle bacilli in milk particularly difficult to 

 destroy ? 



20. Has commercial pasteurization in the past been generally a guarantee for 

 the destruction of the tubercle bacilli in milk ? 



21. What is the effect of a reliable pasteurization upon the enzymes in milk ? 

 22^ What are enzymes? 



23. Describe Storch's test for detecting peroxydases in milk? 



24. Describe Rullman's modification of the Storch test. 



25. What is the effect upon peroxydases in milk if the latter is heated for one 

 hour at 70 C.? 



26. Describe the method of home pasteurization of milk. 



27. Discuss the advantages and disadvantages of pasteurization. 



