MEAT AND MEAT PRODUCTS. 17 



If too dilute, the solution may often be concentrated by precipitating the coloring 

 matter as a lake, a allowing it to settle, decanting off the water, dissolving in hydro- 

 chloric acid and making alkaline with ammonia. 



In extracting with 50 per cent alcohol, the proteids of the meat are coagulated, 

 with the formation of a pale, almost white, color. If the meat is not discolored dur- 

 ing this extraction, it is probable that some foreign color is present. b 



Marpmann b examines sausages microscopically for the presence of coloring matter 

 after dehydrating with alcohol and xylol consecutively, removing the xylol with car- 

 bon tetrachlorid, and immersing in cedar oil until the natural colors of the meat 

 have disappeared. 



(B) MEAT EXTRACTS. 



1. PREPARATION OF SAMPLE. 



Liquid and semiliquid meat extracts and similar preparations should be removed 

 from the container and thoroughly mixed before sampling. With many liquid 

 preparations a sediment is found in the bottom of the container which will be over- 

 looked if great care is not taken. 



2. DETERMINATION OF WATER. 



Follow directions given on page 10, employing about 2 grams of powdered prepa- 

 rations, about 3 grams of preparations of pasty consistency, and from 5 to 10 grams 

 of liquid extracts, according to the solid contents. Dry the powdered preparations 

 directly without admixture. Dissolve the pasty preparations in water and dry with 

 sufficient ignited asbestos or pumice stone to absorb the solution. Tin or lead dishes 

 or Hofmeister glass dishes, are often convenient with samples in which the residue 

 is to be extracted for fat, as the dishes may be cut or broken and placed in the 

 extraction tube with the sample. 



3. DETERMINATION OF ASH. 



Proceed as directed on page 10. In case of pasty preparations, add sufficient 

 water to effect solution and evaporate to dryness in order that the solids may be 

 distributed evenly over the bottom of the dish. 



4. DETERMINATION OF FAT. 



Transfer the residue from the determination of water to the tube of a continuous 

 extraction apparatus, wash any fat adhering to the dish into the tube with ether, 

 and extract with ether sixteen hours. 



5. DETERMINATION OF NITROGENOUS SUBSTANCES. 



(a) TOTAL NITROGEN. 



Employ either the Kjeldahl or the Gunning method. 



(b) DETERMINATION OF MEAT FIBER. 



Dissolve in cold water 5 grams of powdered preparations, from 8 to 10 grams of 

 extracts of pasty consistency, or from 20 to 25 grams of fluid extracts; filter and 

 wash with cold water. Transfer the filter paper and contents to a Kjeldahl llask 

 and determine nitrogen as directed under total nitrogen. In case of a large amount 

 of insoluble matter, make up to a definite volume, filter through a fluted filter paper, 



Bremer, Forschungsber., 1897, 4, 46. 



i>Ztschr. ang. Mikr., 1895, 1, 12. 



"Allen, Com. Org. Anal., 2d ed.. vol. 4, p. 3:24. 



ir,Ms No. 6502 2 



