576 EXPERIMENT STATION KECORD. 



to detect a heated flavor, it is believed to be impossible to make a statement 

 with reference to the exposure necessary to produce this flavor. 



"An exposure of 50 minutes at 145° is satisfactory for half pints, pints, or 

 quarts of milk. Jlxposures satisfactory for milk appear to be satisfactory for 

 cream, if we can judge from the results obtained witli pint bottle.s. 



" The exposure of milk to air during tlie heating process liad no detectable 

 influence on either the creaming ability or the detection of a heate<l flavor. 



" Milk i)asteurized in bottles by an exposure of 50 minutes in water at a tem- 

 perature of 145° underwent much the same type of fermentation as good raw 

 milk although in the former case the ai^pearauce of tlie fermentation was, as 

 would be expected, materially delayed. 



"As the vat temperature is increased above 145° the results obtained ai'e pro- 

 gressively less desirable. A vat temperature of 140° is objectionable mainly on 

 account of the long exposure necessary. 



" With short exposures at various vat temperatures an increased creaming 

 ability of tlie milk so treated was frequently observed but. with exposures which 

 would satisfy tlie requirements regarding bacterial efficiency, such an increase 

 was not observed. 



"Final package pasteurization did not decrease undesirable flavors in milk 

 and In some cases seemed to intensify them. 



" Cream witii a slightly increased acidity is undesirable for final package 

 pasteurization because of the appearance of the heated cream as well as because 

 of the sensation it gives to the tongue. 



"A flavor was imparted to the milk by the paper lining of the cap in some 

 cases. This defect has apparently been recognized by tlio manufacturers and a 

 cap with a parchment paper lining is at present being made." 



Experiments on the pasteurizing of milk in bottles, Wihgmann (Mitt. 

 Deut. Milchw. Ter., 31 (191-i), July, pp. 149-165, figs. 5).— Successful experi- 

 ments are reported on pasteurizing milk in bottles at from 64 to 66° C. (147.2 

 to 150.8° F.) for A hour. The bacteria content was materially decreased and 

 the keeping quality greatly increased. A variety of forms of bacteria were found 

 in raw material but in the pasteurized product only lactic acid bacteria, isolated 

 Bacillus mesentcricus, and some few resistant forms were found. The apparatus 

 and method of pasteurizing is described. 



Testing and handling" dairy products, C. Larsen and J. M. Fuller {South 

 Dakota Sta. Bui. 152 {1914), pp. 28-56, figs. 8).— Items discussed in this bulle- 

 tin are methods of testing milk and cream for milk fat, testing cream for acidity, 

 care of the separator, causes of variation in the cream test, and methods of pro- 

 ducing liigh quality cream. 



Preserving milk samples for examination, J. Tillmans. A. Splittgebbeb, 

 and H. Eiffart (Ztschr. Untersuch. Nahr. u. Genuss)ntL, 21 {1914), Xo. 12. pp. 

 893-901). — In tests with various preservatives of milk it was found that thymol, 

 phenol, creosote, and sodium fluorid cause the milk to coagulate after 24 to 

 48 hours. Bichromate of potash, owing to the intense yellow color it gives to 

 milk, does not allow an accurate determination of the degree of acidity to be 

 carried out. Chloroform causes an increase of refraction and of fat content, 

 and creosote a decrease of specific gravity. Thymol and creosote weaken the 

 diphenylamin reaction to a considerable extent, as is also tlie case with oil 

 of mustard and phenol. Bichromate of potash causes the milk to give a strong 

 IX)sitive reaction with diphenylamin, even without the addition of a nitrate. 



Corrosive sublimate appears to be the most satisfactory of any of the pre- 

 servatives tried. When used in a 0.04 to 0.03 per cent solution it preserves milk 

 quite fresh for 120 hours without any noticeable increase in acidity. It has 

 no action whatever upon the milk constants and allows the quantitative deter- 



