FOOD-COLOR REQUIREMENTS. 25 



Tomato pulp frequently comes into commerce colored with a coal-tar color; the pur- 

 xrae of such coloring is to impart to the goods the appearance of having been prepared 

 nth extraordinary care. In all these cases it is not at all a question of a harmless 

 hange of the natural condition of the food product, but of improper manipulations 

 rhich are adapted to deceive the purchaser as to the real value, of the goods; even, 

 ndeed, to mask the danger to health. 



III. FOOD-COLOR REQUIREMENTS. 

 ADAPTABILITY FOR SPECIAL PURPOSES. 



Not all coal-tar colors are adapted for use in food products. 

 Colors are the more desirable for this purpose the higher their tinc- 

 ,orial power, and the greater the resistance they offer to the action 

 f the materials with which they are to be used, and under the con- 

 litions existing. Obviously only such colors as of themselves have 

 .heir tinctorial properties fully developed can be used, and all such 

 jolors as require a mordant to develop or bring out the color are not 

 it for nor capable of use in food products. 



Further, if the colored material is subjected to varying tempera- 

 /ures in the process of manufacturing foods, it should be able to 

 withstand the effects of such temperatures, as, for example, in the 

 nanufacture of candies. The colors should also withstand the action 

 >f reducing agents, such as are generated in the course of fermenta- 

 ion and decomposition of the food product, or where a preservative 

 uch as sulphur dioxid is added to the food product to minimize the 

 iffect of decomposition of the food upon the color. Such colors are 



t on the European market, and perhaps, but not necessarily, 

 >n the United States market with preservatives added to them. 

 Most of the coal-tar colors are susceptible to the action of sulphur 

 lioxid, particularly when the latter has been used in the decolor- 

 izing of glucose, and Uranin (510) is one of the colors found to have 

 the greatest resistance to the sulphur dioxid which may remain 

 combined in candy. 



For example, the book entitled " Henley's Twentieth Century 

 Book of Receipts, Formulas and Processes," published in 1907, on 

 ipage 359, says of sausage color: 



It is absolutely necessary in using aniline colors to add a disinfectant to the dye- 

 stuff solution, the object of which is, in case the sausage should commence to decom- 

 pose, to prevent decomposition of azo-dyestuff by the disengaged hydrogen. Instead 

 of boracic acid, formaline may be used as a disinfectant. 



J. Fraenkel (Arbeit. Kaiserl Gesundh. 1902, v. 18, pp. 518-521; 

 iabst. Zts. Nahr. Genussm., 1902, v. 5, p. 986) reports as follows on 

 i the composition of colors used in coloring sausages, meats, and 

 : preserves : 



1. Blood color: Moisture, 15 per cent; common salt, 6.6 per cent; borax, 21 per 

 cent; and Ponceau 2 R (G. T. 55). 



