228 Condensed Milk and Mii,k Powder 



3. "detection of caramel (in the curd) 



"If the fat-free curd is colored a dull brown, caramel is to 

 suspected. Shake a lump of the curd, as in (2), with strong hyd 

 chloric acid in a test tube and heat gently. In the presence of ca 

 mel the acid solution will gradually turn a deep blue, as will a 

 the white, fat-free curd of an uncolored milk, while the curd its 

 does not change color. It is only when this blue coloration of : 

 acid occurs in connection with a brown colored curd, which its 

 does not change color, that caramel is to be suspected, as d 

 tinguished from the pink coloration produced at once under simi 

 conditions by anilin orange." 



4. "LYTBGOE'lS' TEST :FOR AlNIDIN ORANGE 



"Treat about 10 c.c. of the milk with an equal volume of hydi 

 chloric acid (sp. gr. 1.20) in a porcelain casserole and give the d: 

 a slight rotary-motion. If an appreciable amount of anilin orar 

 is present, a pink color will at once be imparted to the curd partic 

 as they separate." 



DETECTION OF SUCROSE IN MILK TO WHICH SUCRATE OF LIM 

 (VISCOGEN) HAS BEEN ADDED 



25 c.c. of milk or cream are shaken in a small Erlenmeyer fk 

 with 10 c.c. of a 5 per cent, solution of uranium acetate, allowed 

 stand for five minutes and filtered through a folded filter. If 1 

 filtrate is not clear, pour through filter again until clear. To 10 c 

 of the filtrate 2 c.c. of a cold saturated solution of ammonii 

 molybdate and 8 c.c. of hydrochloric acid (one part of 25 per ce 

 acid to seven parts of water) are added. The mixture is shak 

 and placed in a water bath at 80 degrees C. for five minutes. In t 

 case of the presence of sucrose the solution becomes more or h 

 blue according to amount of sucrose present. Upon standing in 1 

 water bath for a longer time the blue color becomes deeper. At f 

 end of ten minutes it is deep blue, while in the absence of sucrose 

 the end of five minutes the color is faintly green, which deepe: 

 but never acquires a blue shade. By means of this method as lit 

 as .05 per cent, sucrose can be detected. 



1 Barthel, Milk and Dairy Products 



