The Bulletin. 29 



examination of samples. 



Sixty-four samples, representing 30 different brands of baking 

 powders offered for sale in North Carolina, have been analyzed re- 

 cently. 



The samples classified according to the acid material present are as 

 follows : 



Brands. Samples. 



Tartrate Powders 6 9 



Pliosphate Powders 2 7 



Alum Powders 17 43 



Alum-Phospliate Powders 4 4 



Ahim-Phosphate-Tartrate Powders 1 1 



Total 30 G4 



Only one sample was found to be adulterated, No. 4515. "Pler- 

 mitage" contained 50.81 per cent of finely ground insoluble mineral 

 matter. 



A microscopic examination of this insoluble mineral matter by 

 Mr. C. D. Harris showed it to be ground talc (tremolite). It appears 

 under the microscope to be composed of sharp, needle-like crystals. 

 It is a dangerous admixture in food products. 



A sample of "Hermitage" baking powder was examined by this 

 Department in 1902 and was found to contain 18.42 per cent of 

 ground tale. 



While under this examination only one sample was found adulter- 

 ated, 38 samples were not properly labeled, the acid ingTedient not 

 being named, as is required. Of the 38 samples not properly labeled 

 one was a tartrate powder and 37 were alum powders. 



There is some prejudice in the minds of the public against the use 

 of alum powders, and for that reason some manufacturers dislike to 

 brand their products "alum powders." 



In the analysis of these powders quantitative determinations were 

 made of the carbon dioxide gas (the active leavening constitu- 

 ent to which powders owe their value) and the insoluble ash, though 

 qualitative tests were made to ascertain the materials from which 

 the powders were made, as well as any impurities or adulterants. 



On standing, baking powders, unless put up practically air-tight, 

 gradually lose their leavening power, and the longer a powder stands, 

 other things being equal, the lower its leavening power will be. If 

 a powder is not put up dry and kept so, there will be a gTadual 

 decomposition or loss in leavening power. 



