COMPOSITION AND FOOD VALUE OF BUTTER 13 



Glutaminic acid (amino-glutaric acid) 



COOH . CH 2 . CH 2 . CH(NH 2 ) . COOH 

 Aspartic acid (amino-succinic acid) 



COOH . CH 2 . CH(NH 2 ) . COOH . . 

 Cystine (amino-thialactic acid) 



S - CH 2 - CH(NH 2 ) . COOH 1 



S - CH 2 - CH(NH 2 ).COOHJ 

 Serine (a-amino-j8-hydroxy-propionic acid) 



CH 2 OH.CH(NH 2 ).COOH . . . 

 Tyrusine (oxyphenyl-a-amino-propionic acid) 



C 6 H 4 (OH) CH 2 CH(NH 2 ).COOH . 



Oxyproline (OH . C 4 H 7 N . COOH) 



Histidine (a-amino-/3-imidazol-propionic acid) 



HC = C . CH 2 . CH(NH 2 ) . COOH 



N 



PER CENT 



15.55 



1.39 



0.50 



4.50 

 .23 



HN 



CH 



Arginine (5-guanidino-a-amino-valeric acid) 



NH 



II 



(H 2 N)C . NH . CH 2 . CH 2 . CH 2 . CH(NH 2 ) . COOH . 

 Lysine (a, e, diamino-n-caproic acid) 



CH 2 (NH 2 ) . CH 2 . CH 2 . CH 2 . CH(NH 2 ) . COOH 

 Tryptophane (indol-amino-propionic acid) 



C . CH 2 . CH(NH 2 ) . COOH 



,C.H 



NH 



2.50 



3.81 

 5.95 



1.50 



Diamino-trioxy-dodecanic acid 



(CiiHi 8 (OH) 3 (NH 2 ) 2 . COOH structure unknown) . . .75 



Ammonia 1.61 



Sulfur 0.76 



Phosphorus 0.85 



Because of the presence of water and of acids, the casein 

 may hydrolyze and consequently many of the above 

 products are likely to be present in butter. Thus, con- 

 sidering the complexity of the fat and casein, the student 

 of butter finds a large field in the flavors of this product. 



