30 MASS. EXPERIMENT STATION BULLETIN 398 



3. Vitamin K Content of Cocoa and Dairy Products. (W. S. Mueller.) It 

 has been observed in the study on the availability of the iron of cocoa that the 

 blood clotting time was shortened when the rats were fed cocoa. This observa- 

 tion led to an investigation of the vitamin K content of cocoa and dairy products. 

 Of the various dairy and cocoa products fed, only cultured buttermilk and cocoa 

 shell had any great effect on blood clotting time. These results indicate that the 

 decrease in blood clotting time, which had been observed for rats receiving cocoa, 

 is not directly tied up with vitamin K. 



4. The Tannic Substances of Commercial Cocoa Powders and the Determination 

 of Cacao Purple. (W. S. Mueller, with the cooperation of J. W. Kuzmeski.) 

 Commercial cocoa powders have been analyzed for cacao purple by Ulrich's 

 method. The average for 6 Dutch processed samples was 8.44 percent and for 

 9 unprocessed samples, 12.72 percent. The total ash of the ferric chloride pre- 

 cipitate varied from 11.48 to 18.24 percent. The ash of the precipitate consisted 

 mainly of iron and phosphorus, present either as separate oxides or in combina- 

 tion as ferric phosphate. In general, Ulrich's method for the determination of 

 cacao purple in cocoa products apparently leaves much to be desired. However, 

 the results from this study indicate that the ferric chloride precipitate would 

 measure the cacao purple content more nearly accurately if the washing procedure 

 were modified and a correction made for the ash contained. 



Improving the Flavor and Keeping Properties of Milk and Some of its Products. 



(W. S. Mueller.) Further work is being dene on evaluating various substances 

 as antioxidants for butterfat. At the outset of this study, the peroxide test was 

 used in conjunction with the organoleptic tests for determining the effectiveness 

 of the various antioxidants. As the work progressed, it became apparent that 

 the peroxide test was not reliable for replacing organoleptic tests. A new chemical 

 test (Chlorophyll Value Test by M. R. Coe, Eastern Regional Research Labora- 

 tory, Philadelphia) is being used for butterfat and seems to correspond more 

 closely to organoleptic rancidity than the peroxide test. Today it is more impor- 

 tant than ever before that we know how to prevent spoilage of butterfat because 

 the product is being transported and stored under adverse conditions. 



A Study of Vanilla Sugars for Flavoring Ice Cream. (W. S. Mueller.) The high 

 price of grain alcohol is discouraging the use of ordinary vanilla extract for flavor- 

 ing ice cream. Vanilla sugars appear to be a desirable substitute and their ad- 

 vantages and limitations for use in ice cream are being studied. Sixteen samples, 

 including true, imitation, and mixtures of true and imitation, are being analyzed 

 and used to flavor ice cream. In general, the vanilla sugars were found to be of 

 excellent quality and appeared to be suitable for the purpose, and tests with 

 consumers indicated that it was difificult to distinguish between the true vanilla 

 and the imitation product. 



An Explanation of the Increased Efficiency of Gelatin in Ice Cream Mix Whe n 

 Initially Aged at 68°F. (W. S. Mueller.) Results obtained in this study indicate 

 that the initial aging temperature of 68°F. produced a more closely knit gel 

 structure, which has many more inter-connected filaments than a structure 

 produced by aging at the low temperature only. The more numerous gel fila- 

 ments are effective in obstructing the formation of large ice crystals. This ap- 

 pears to be the most plausible explanation for the smoother texture of gelatin in 

 ice cream when initially aged at 68°F. In view of the present national emergency, 

 it seemsjparticularly timely to emphasize the more effective use of gelatin. 



Iodoform Taste in Milk. (H. G. Lindquist.) In a study made on off-flavors 

 in milk, iodoform flavor was detected in a few samples. Investigation showed 



