908 FOODS AND FOOD ADULTERANTS. 



Fat. Extract 2 grains of the finely powdered oofleein Soxlet's apparatus, or in one 

 of the various modifications of this apparatus, with anhydrous alcohol-free ether. 

 Remove the other from the extract by distillation and weigh the residue. Estimate 

 the caffeine in this residue and deduct. The caffeine will probably amount to a small 

 fraction of a per cent. 



The sample of whole coffee beans may be prepared for analysis by means of a file 

 or rasp. Particles of iron in the raspings should be removed by means of a magnet. 



Albuminoid nitrogen, (Seep. 890.) 



Crude fiber. 1 A quantity (6 to 8 grams) of the finely ground material is weighed 

 into a flask, and treated several times with very dilute caustic potash (0.2 per cent), 

 in order to remove the greater part of the albuminoids, lloil several times witli a 

 somewhat stronger solution of caustic potash (1.25 per cent), and after total removal 

 of the alkali boil repeatedly with acetic acid. The, residue after thorough washing 

 with water is dried at 105 C. and weighed. 



Caffetannic add. Owing to the lack of a method for the estimation of caffetannic 

 acid, the following was devised by Mr. W. H. Krug, of the Chemical Division, for 

 this report: 



Weigh out duplicates of 2 grams each. Add 10 cc. of water and digest for 36 hours. 

 Then add 25 cc 90 per cent alcohol, and digest for 24 hours more. Filter, washing 

 the residue on the filter with 90 per cent alcohol. The filtrate contains tannin, caf- 

 feine, and traces of coloring matter and fat. . Heat it to the boiling point and add a 

 boiling concentrated solution of lead acetate. If this is carefully done a canVtan- 

 nate of lead containing 49 per cent lead will be precipitated. As soon as the pre- 

 cipitate has become flocculeut it is collected on a filter, washed with 90 per cent 

 alcohol until the washings show no lead with ammonium sulphide, washed with ether 

 to remove traces of fat, dried and weighed. The composition of the precipitate is 

 Pb :3 (Cift Hi 5 Ota). Therefore weight of precipitate: weight of caffetannic acid 

 :: 1263.63: 652. 



Total soluble and insoluble ask. Refer to page 891 under the analy- 

 sis of teas for methods of asli determinations. 



The color of the ash should be noted. A red ash is indicative of the 

 use of Venetian red or other iron compounds in coloring the sample. 



ADULTERATION DEFINITION. 



Referring to the law of the State of New York (p. 879), the adul- 

 teration of coffees may be denned as follows: The addition of foreign 

 matter of any kind to reduce the strength or affect the quality; the sub- 

 stitution of cheaper substances in part or wholly for the genuine coffee; 

 facing or coloring in imitation of better grades or to conceal damage. 



The use of cereals in so-called " blending " should be considered an 

 adulteration. The cereals act simply as a diluent, increasing the 

 weight and bulk without corresponding benefit to the purchaser. 

 These remarks might also well be applied to chicory, were it not that 

 many persons show a- decided preference for coffee containing this sub- 

 stance. Notwithstanding this preference, chicory is and should be con- 

 sidered an adulterant, except when the package containing the mixture 

 is distinctly branded and the proportions of pure coffee and chicory 

 indicated. It is stated that chicory possesses medicinal properties of a 

 diuretic and laxative character which render its excessive use objec- 



1 Unpublished work of Mr. W. Maxwell, IT. S. Department of Agriculture. 



