SCARES ET AL.; CONDENSED FISH SOLUBLES 



Table 2. — Analytical data on condensed solubles. 



^ Corrected for ammonia-nitrogen 5.15. 



COMPOSITION OF CONDENSED 

 FISH SOLUBLES 



Analytical data (Table 2) published by Lee 

 (1956) showed that condensed fish solubles con- 

 tained approximately 50% dry matter, which in- 

 cluded protein (Kjeldahl nitrogen x 6.25), fat, 

 minerals, and vitamins. According to the above 

 author the major variable factors affecting com- 

 position were species and age of the fish, season 

 and location of the catch, handling techniques, 

 and type of plant equipment used during pro- 

 cessing. Data describing other types of fish sol- 

 ubles produced in the United States are very 

 scanty. However, Table 2 lists some average 

 results for herring solubles reported by March 

 (1962) and Lassen, Bacon, and Dunn (1951), 

 and these appear very similar to the menhaden 

 data. 



Table 3 shows the proximate, total fat, and 

 ammoniacal nitrogen composition of 24 con- 



Table 3. — Proximate composition, total fat, and ammo- 

 niacal nitrogen content of menhaden fish solubles.^ 



Analyses 



Protein (N X 6.25) 



Ash 



Ether fat 



Total fat 



Moisture 



.Ammonia as % N 



^ Scares, MiHer, and Ambrose (1970). 



densed menhaden fish solubles samples collected 

 during 10 months of the 1969 fishing season 

 (Scares, Miller, and Ambrose, 1970). These 

 samples were obtained from seven different fish 

 meal plants located along the Middle Atlantic 

 and Gulf coasts, and they represent regular com- 

 mercial production. The methods for proximate 

 analyses were all standard AOAC (Association 

 of Official Analytical Chemists) methods except 

 total fat, which is a chloroform-methanol extrac- 

 tion method of Bligh and Dyer that was mod- 

 ified by Smith, Ambrose, and Knobl (1964). 

 Since the data from the Atlantic and Gulf sam- 

 ples did not differ significantly (although they 

 are made from two different species of men- 

 haden), it is presented together as an average. 

 In general, these analyses indicate that the solids 

 content is slightly more than 51 % . The average 

 concentration of protein (Kjeldahl N X 6.25) 

 was 31.8% and that of ash was 7.8%. If these 

 values are converted to a dry basis, they are very 

 similar to those for menhaden fish meal reported 

 by Kifer and Payne (1968) and Kifer, Payne, 

 and Ambrose (1969). This is not to say that 

 dried fish solubles is equivalent to fish meal in 

 protein quality, but this only points out the rel- 

 atively high protein content of this material even 

 after allowing for nonprotein nitrogen (Table 3) . 

 The fat content, expressed on a dry basis is some- 

 what higher, however, than that found in fish 

 meal. Ammoniacal nitrogen (which included 

 volatile amines, etc.) makes up about 0.5% of 

 the total nitrogen. 



257 



