MEAT AND MEAT PRODUCTS. 



115 



(b) MEAT FIBER." PROVISIONAL. 



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 

 KjVldahl flask and determine nitrogen as directed under total nitrogen. In 

 f a largo amount of insoluble matter, make up to a definite volume, filter 

 through a folded filter, and determine nitrogen in an aliquot of the filtrate; 

 deduct the percentage of nitrogen in the total filtrate from the percentage of 

 total nitrogen to obtain the percentage of nitrogen in meat fiber. Multiply 

 the percentage of nitrogen by G.25 to find the percentage of meat fiber. 



(C) COAGULABLE PROTEIDS. PROVISIONAL. 



Employ as large an aliquot of the filtrate as practicable when the nitrogen of 

 meat fiber has been determined by difference. Make the filtrate from the meat 

 fiber slightly acid by the addition of acetic acid or sodium hydroxid, as may be 

 necessary ; boil for two or three minutes, cool to room temperature, dilute to 

 500 cc, and pass through a folded filter. & 



Determine nitrogen in 50 cc of the filtrate by the Kjeldahl or Gunning method 

 (page 5, under !< I. Fertilizers."). 



Ten times the nitrogen so obtained deducted from the percentage of soluble 

 nitrogen (which in turn is obtained by deducting percentage of nitrogen occur- 

 ring as meat fiber from the total nitrogen) gives the percentage of nitrogen 

 present as coa. mil able proteids. Multiply this figure by 6.25 for the percentage 

 < 1 e< a-.Tiable proteids in the sample. 



(d) SYNTONIN (ACID ALBUMIN). PROVISIONAL. 



Exactly neutralize the filtrate from the determination of coagulable proteids 

 with sodium hydroxid, using litmus as indicator, and allow to stand until the 

 precipitate settles. If only a small amount of syntonin is precipitated, separate 

 it with an ordinary filter, wash with water, and determine its nitrogen content 

 by means of the Kjeldahl or Gunning method. If present in any considerable 

 quantity, dilute to a definite volume, filter through a folded filter, and determine 

 nitrogen in 50 cc of the filtrate. 



Deduct the nitrogen thus obtained (calculated to total volume) from the 

 nitrogen in the filtrate from the coagulable proteids (c) to obtain the syntonin 

 nitrogen. Multiply this by 6.25 to obtain the syntonin. 



(e) AMMONIA. PROVISIONAL. 



Employ the magnesium-oxid method as directed on page 9, under " I. Fer- 

 tilizers." 



(f) PROTEOSES AND GELATIN.^ PROVISIONAL. 



Evaporate the filtrate from the determination of syntonin to a small volume 

 and saturate with zinc sulphate. (Use as large an aliquot of the filtrate as is 

 practicable when the percentage of syntonin is determined by difference.) 

 About 85 grams of powdered zinc sulphate are necessary for the saturation of 



"Allen, Commercial Organic Analysis, 2d ed., 4: 324. 



6 It is always tedious and unsatisfactory and sometimes almost Impossible to filter and 

 wash the coagulated proteids. The work is greatly simplified, therefore, by using a 

 folded filter and employing aliquots of the filtrate, as in this way complete filtration and 

 washing of precipitates becomes unnecessary. 



c Bomer, Zts. anal. Chem., 1895, 5 : 562 ; also Mallet, TJ. S. Dept. Agr., Division of 

 Chemistry, Bui. 54. 



