BUREAU OF CHEMISTRY. 443 



FOOD COLORS. 



Two extensive studies on coal-tar colors have been brought to 

 completion during the past year under the direction of B. C. Hesse, 

 of New York, a color expert appointed for the purpose of making 

 these investigations. The food-inspection laboratories at Washing- 

 ton, at New York, and at Seattle have also done a great deal of work 

 along this line. The first investigation included the original work 

 done in the bureau and also a comprehensive survey of the literature 

 with special reference to the harmrulness of coal-tar colors and their 

 physiological effects. These data, on which the selection of the seven 

 permitted colors was based, are in the hands of the printer. The 

 second study consisted in the investigation of methods for determin- 

 ing the chemical identity of coal-tar dyes used in food products, 

 as a result of which 134 different chemical individuals have been 

 grouped in 10 analytical tables. Of these only 19 are paired, leaving 

 115 dyes wliich can be conclusively identified by these tables without 

 known specimens. The dyes of each of these pairs can be thus 

 distinguished from every other pair and from each of the other 

 115 dyes, but the pairs can be distinguished from each other only by 

 having known specimens of at least one member of the pair. In no 

 case is one of the permitted dyes of Food Inspection Decision No. 76 

 paired with another dye. The tables include all but three of the 

 dyes said to be used in food products, and these appear to be now 

 obsolete; they also include all dyes that have been examined physio- 

 logically and which are not obsolete or impracticable for use in foods. 

 These data are now in process of compilation. 



The investigation of the character or artificial colors used in various 

 food products has been continued and admission into the United 

 States has been denied to foods colored with unpermitted dyes. Con- 

 siderable attention has also been given to the natural coloring matter 

 in foods, especially in flours in connection with the bleacliing process, 

 and the application of the spectroscope to the general problem. A 

 study has also been begun of the coloring matter of the common 

 foods which have a characteristic color with a view to estabhsliing 

 another means for the detection of the substitution of one food 

 for another. 



MANUFACTURE AND COMPOSITION OF EGG NOODLES. 



This product is assuming considerable importance, and it has become 

 necessary to be able to determine from the examination of the fuiished 

 article the proportion of eggs used in its preparation. With this in 

 view, a representative of the bureau visited a large factory and with 

 the assistance of trained workers manufactured under commercial 

 conditions egg noodles made with varying amounts of egg and from 

 various classes of eggs. The analyses of these preparations have 

 afforded valuable data for judging accurately of the quality of com- 

 mercial products. 



COMPOSITION OF BEER MADE FROM VARIOUS MATERIALS. 



In collaboration with a local brewery, samples have been taken of 

 various beers at different stages of their manufacture, and the data 

 obtained from their examination are believed to be of value in the 



