ANALYSIS OF LABORATORY MEAT JUICES. 



19 



In muscle tissue there is found approximately 75 per cent of water. 

 Of the 100 parts of nitrogen in beef, 75 parts consist of proteid mat- 

 ter insoluble in water; 10 parts consist of water-soluble proteid, and 

 12.5 parts of extractives, which are also water soluble. Unfortunately 

 in making these analyses the total kreatinin was not determined. 

 As before stated, all of these juices are characterized by a large 

 amount of coagulable proteid, while the percentage of the other 

 constituents present seems to vary with the water content. The small 

 amount of sodium chlorid in the ash is noticeable, and the amount 

 of nitrogen present in the form of albumoses and peptones is small, 

 as would be expected in a true meat juice. It is evident from Table 

 VI that there is considerable water-soluble amido nitrogen present 

 in the juice of meats. 



Table VI. — Meat juices prepared in laboratory. 



Serial 

 No. 



1705)1 



17092 

 17091 

 17092 

 19766 

 19767 



19785 



19786 



19787 



Preparation of juice. 



Round beef, cold pressed 



Chuck beef, cold pressed 



Round beef pressed at 60° C 



Chuck beef pressed at 60° C 



Juice from beef chuck at 60° C. 

 Juice pressed from sirloin steak 



and water 



Juice extracted from sirloin 



steak by cold pressure 



Juice extracted from beef chuck 



by cold pressure 



Juice extracted from beef chuck 



by cold pressure after 6 hours 



at60°-100°C 



Composition of sample. 



Total 

 nitro- 

 gen. 



Per ct. 

 2.08 

 1.74 

 1.16 

 1.09 

 1.09 



1.18 



.48 



.43 



.24 



Insolu- 

 ble 



nitro- 

 gen. 



Per ct. 



0.16 



.29 



Coag- 

 ulable 

 nitro- 

 gen. 



Per ct. 

 1.37 

 .98 

 .68 

 12 I .41 



.54 

 .34 

 .34 



Proteose 

 nitrogen. 



Per ct. 

 0.06 

 .07 

 .04 

 .07 

 .42 



.20 



Trace. 



Trace. 



Trace. 



Peptone 

 nitrogen 



Per ct. 



0.16 



.11 



.01 



.21 



.18 

 None. 

 None. 



.12 



Amido 

 nitro- 

 gen. 



Per ct. 



0.33 



.29 



.43 



.27 

 .18 



.26 



.14 



.09 



Unde- 

 ter- 

 mined 

 matter. 



Per ct. 

 0.47 

 1.03 

 1.90 

 .40 

 2.92 



.94 



.85 

 .59 



.25 



