ANNUAL REPORT, 1943-44 31 



Overrun of chocolate milk is an important consideration in formulating laws or 

 regulations pertaining to the product, and in determining plant losses, cost of 

 the product, and nutritive value. Commercial chocolate milk was found to vary 

 in overrun from 4 to 14 percent. The average overrun was higher in chocolate 

 milk prepared with syrup than in chocolate milk prepared with dry ingredients 

 because the syrup often contains a considerable amount of water. A formula 

 has been developed for computing the overrun in certain kinds of chocolate milk, 

 and it is expected that further study will make it applicable to all chocolate milks. 



Indications are that the destruction by cocoa of certain vitamins in milk may 

 be significant. This should be of interest to the many nutritionists who have 

 endorsed the inclusion of cocoa in milk as a means of adding more widespread 

 appeal to this protective food. 



A Study of the Effect of Certain Antioxidants on the Flavor and Keeping 

 Properties of Millc and Some of Its Products. (W. S. Mueller.) Further attempts 

 were made to find a chemical method which would detect and measure oxidative 

 rancidity in butter and other dairy products. The method desired is one that 

 will (1) detect the very earliest stages in the process of rancidification, (2) measure 

 quantitatively the state of oxidation, and (3) make possible a comparison of the 

 potential keeping qualities of various dairy products. 



The "chlorophyll value" test, which has been recommended for testing veg- 

 etable oils, has been investigated and appears to have a doubtful value as a 

 test for butter fat rancidity or stability. This test appeared to measure the de- 

 gree of rancidity which had been activated by light, but not that activated by 

 heat. The chief difficulty encountered when this test was applied to butter fat 

 was the masking of the "endpoint" in the titration by the yellow fluorescence of 

 butter fat. The use of various light filters did not remedy the difficulty. 



Sterilizing Agents for Dairy Use. (W. S. Mueller, E. Bennett, and J. E. Fuller.) 

 In an attempt to find a sterilizer for dairy equipment which would take the place 

 of chlorine, 45 samples of wetting or cationic agents have been collected, and 15 

 of these samples have been compared with a commercial chlorine sterilizing com- 

 pound. Of the 15 samples already studied, 8 showed sufficient sterilizing proper- 

 ties to warrant further study, while 7 were discarded as ineffective. 



Potassium meta bisulfite was found to be unsuitable as a sterilizing agent for 

 dairy equipment because it was too corrosive to metals and also because its 

 sterilizing properties were too weak. This was found to be true for acid sodium 

 sulfite also. Sulfur dioxide was found to be a strong sterilizing agent but very 

 corrosive. Buffering all three of the sulfur compounds in order to reduce their 

 corrosiveness also greatly reduced their sterilizing properties. 



The fact that sulfur compounds are excellent fungicides has led many people 

 to believe that they are also good germicides. The negative results obtained in 

 this study should aid in clearing up the misconception. 



Effect of High-Temperature Short-Time Pasteurization on the Ascorbic Acid, 

 Riboflavin, and Thiamin Content of Milk. (A. D. Holmes, H. G. Lindquist, 

 C. P. Jones, and Anne W. Wertz.) Over a period of 18 months, samples were 

 taken from 30 lots of raw milk, and taken again after the milk had been pasteur- 

 ized by the high-temperature short-time method of pasteurization (in an Electro- 

 Pure pasteurizer) at temperatures varying from 161° to 181 °F. The vitamin 

 assays for ascorbic acid, riboflavin, and thiamine showed that there were no sig- 

 nificant losses of these vitamins due to this method of pasteurization. 



