28 COAL-TAR COLORS USED IN FOOD PRODUCTS. 



SUITABILITY OF SHADES OF PERMITTED COLORS AND MIXTURES) 



OF SAME. 



The shades produced by the seven permitted colors are, respec-l 

 tively, yellow, orange, blue, green, red, bluish scarlet, and brilliant! 

 cherry red. As statements are found in the literature against the! 

 use of all of the chemical individuals producing a brown or a violetl 

 shade, it will be necessary to produce these shades by a proper com-l 

 bination of two or more of the permitted colors. So far no criti-l 

 cism with regard to the shades produced by the seven colors them-I 

 selves and by their appropriate mixture has been made that has been I 

 substantiated. 



Objection has been made to the violet producible from blue and 

 red, on the ground that when applied to a food product, such asl 

 candy, the component parts do not evenly fix themselves upon the 

 material. This objection, however, has not been pressed and proba- 

 bly is not well taken, because of the fact, frequently reported, that 

 few, if any, coal-tar colors are used without admixture of one or more 

 other colors to shade or to tone the original color. This criticism, 

 therefore, of the use of mixed colors can be regarded as not a serious 

 objection. 



One criticism urged with considerable persistency against the seven 

 permitted colors was that none of them would withstand the action 

 of the organic acids ordinarily found in beverages such as lemonade, 

 and it was suggested that no color was proper for use for such pur- 

 poses which would not withstand, unaltered, for a period of 12 hours 

 the action of a 10 per cent solution of citric acid. In urging this 

 objection substitutes were suggested for the permitted colors. The 

 substitutes so urged were Tartrazin (94), Azorubin (103), Orange 

 II (86), Ponceau 4 GB (13), and one other color designated as Scarlet 

 SR, of whose chemical composition no information whatever was 

 forthcoming. (The numbers in parentheses refer to the Green Tables.) 

 Of the five colors suggested it can be said that concerning all but No. 

 103 adverse statements are found in the literature, and No. 86 is spe- 

 cifically regarded by every observer but one as being thoroughly 

 poisonous. The suggested substitute list is, therefore, objectionable 

 on the ground of injuriousness to health. 



To test the validity of the assertion that none of the permitted 

 colors could withstand the action of citric acid, solutions of the sug- 

 gested colors, as well as of the permitted colors, each one in a thou- 

 sand, were submitted to the action of citric acid, added in such quan- 

 tity that it amounted to 10 per cent of the total bulk of solution. 

 This experiment showed that Tartrazin is reddened by citric acid, 

 whereas Naphthol Yellow S loses in tinctorial power to a slight extent. 

 The shade produced by Ponceau 4GB can be closely imitated by a 

 mixture of Naphthol Yellow S, Orange I, and Amaranth, all per- 



