58 FOOD ADULTERATION AND METHODS FOR DETECTION. 



which interferes with the color due to the presence of boric acid. 

 When a drop of household ammonia is added to the colored turmeric 

 paper, it is turned a dark green, almost black color, if boric acid is 

 present. If the reddish color, however, was caused by the use of too 

 much hydrochloric acid this green color does not form. 



CAUTION. The corrosive nature of hydrochloric acid must not be for gotten. It must not 

 be allowed to touch the flesh, clothes, or any metal. 



DETECTION OF COLORS. 



The detection of coloring matter in sausage is often a difficult mat- 

 ter without the use of a compound microscope. It may sometimes be 

 separated, however, by macerating the meat with a mixture of equal 

 parts of glycerin and water to which a few drops of acetic or hydro- 

 chloric acid have been added. After macerating for some time the 

 mixture is filtered and the coloring matter detected by means of dyeing 

 wool in the liauid thus obtained. (See p. -5.) 



SPICES. 



Although ground spices are very frequently adulterated, there are 

 few methods that may be used b} T one who has not had chemical train- 

 ing, and who is not skilled in the use of a compound microscope, for 

 the detection of the adulterants employed. The majority of the sub- 

 stances used for the adulteration of spices are of a starchy character. 

 Unfortunately for our purposes, most of the common spices also con- 

 tain a considerable amount of starch. Cloves, mustard, and cayenne, 

 however, are practically free from starch, and the presence of starch 

 in the ground article is proof of adulteration. 



DETECTION OP STARCH IN CLOVES, MUSTARD, AND CAYENNE. 



A half teaspoonf ul of the spice in question is stirred into half a cupful 

 of boiling water, and the boiling continued for two or three minutes. 

 The mixture is then cooled. If of 'a dark color, it is diluted with a 

 sufficient amount of water to reduce the color to such an extent that 

 the reaction formed by starch and iodin may be clearly apparent if 

 starch be present. The amount of dilution can only be determined by 

 practice, but usually the liquid must be diluted with an equal volume 

 of water, or only one-fourth of a teaspoonf ul of the sample may l>e 

 employed originally. A single drop of tincture of iodin is now added. 

 If starch is present, a deep blue color, which in the presence of a I:UL:V 

 amount of starch appears black, is formed. If no blue color appears, 

 the addition of the iodin tincture should be continued, drop by drop, 

 until the liquid shows by its color the presence of iodin in solution. 



DETECTION OF COLORS. 



Spice substitutes are sometimes colored with coal-tar colors. These 

 products may be detected by the methods given on page 5. 



