are listed in Table 10. Much of the fat was re- 

 moved from the autolysate by centrifugation be- 

 fore soluble and insoluble solids were blended 

 back together and spray-dried. Cooking and 

 pressing of the alewife in small laboratory equip- 

 ment were not as effective in oil removal as had 



been expected. The residual oil in the press cake 

 is reflected in the 25 '^f lipid content of the hy- 

 drolysed press cake product. The normal results 

 of industrial pressing operations would yield a 

 product with a much lower fat content and a 

 higher protein concentration. 



Table 9.- 



-Average values for proximate and amino acid analyses: 

 runs, three processes, and red hake feed. 



replicate 



Table 10. — Average values for proximate and amino acid analyses: replicate 



runs, three processes, and alewife feed. 



Enzyme Alcalase Autolysis Alcalase 



Concentration 0.5% — 0.3% 



Feed Raw fish Raw fish Press cake 



Type of product . . Soluble Whole slurry Whole slurry Raw alewife 



Number of runs . . 3 3 3 3 



Average yield .... 13.0% 18.5% 18.7% 



Proximate composition (average %): 



Protein 76.01 73.79 65.24 17.16 



Moisture 4.89 4.55 4.21 71.07 



Ash 16.52 5.95 9..32 2.74 



Fat 0.21 12.56 25.07 8.35 



Amino acids %( of crude protein): 



Lysine 7.97 7.33 7.42 6.77 



Histidine 1.75 2.27 2.14 1.84 



Threonine 3.93 3.74 3.68 3.14 



Valine 4.88 4.92 4.80 4.94 



Methionine .... 2.51 2..39 2.49 2.44 



Cystine 1.13 1.07 1.22 1.26 



Isoleucine 3.99 4.08 4.14 4.09 



Leucine 7.10 6.89 6.78 6.83 



Phenylalanine . . 3.45 3.50 3.63 3.49 



Tyrosine 2.80 2.83 2.90 2.32 



Tryptophan 0.88 0.65 0.61 0.79 



19 



