PASTEURIZATION 93 



ble flavors is pasteurized, there is not so much possibihty 

 of flavor improvement as when the milk or cream is fresh. 



According to Rogers, Berg, and Davis,^ cream of good 

 quahty may be efficiently pasteurized, from the bacterio- 

 logical viewpoint, if the temperature is raised momentarily 

 to 71° C. (160° F.) . They state that this is near the limit 

 of safety, and that if the bacterial-content of the raw 

 cream is high, a temperature of 74° to 77° C. (165° to 

 170° F.) must be used to secure uniform flavor. Their 

 results, which were based on data of scoring butter when 

 40 and 150 days old, show that the flavor of the product 

 made from pasteurized cream was higher than the raw 

 cream butter. Judging from the bacteria count, this 

 butter was made from sour or very nearly sour cream. 



Hunziker ^ declares that butter made from pasteurized 

 cream shows a decided improvement over that from raw 

 cream of the same quality. He evidently included both 

 sweet and sour cream in this statement. Later he ' 

 shows that in thirty days sour raw cream butter 

 deteriorates two and one-half points more than butter 

 that has been properly pasteurized. Again Hunziker * 

 writes : " The experiment embraces the pasteurization of 

 cream by three difi'erent processes of pasteurization ; 

 namely, vat pasteurization at 145° F. holding for 20 

 minutes, flash pasteurization at 160° to 165° F. and flash 

 pasteurization at 180° to 185° F. The cream for four churn- 



1 Rogers, L. A., Berg, W. N., and Davis, Brooke J., The Tem- 

 perature of Pasteurization for Butter Making, U. S. Dept. of 

 Agri., B. A. I., Cir. 189, 1912. 



2 Hunziker, O. F., Investigations in Dairy Manufactures, 

 Purdue Univ. Agr. Exp. Sta., 28th Ann. Rpt., p. 39, 1915. 



2 Hunziker, O. F., Pasteurization, N. Y. Prod. Rev. and Amer. 

 Cry., Vol. 42, No. 6, p. 236, 1916. 



* Hunziker, O. F., Cream Improvement, Purdue Univ. Agri. 

 Exp. Sta., 29th Ann, Rpt., p. 34, 1916. 



