Page 



Suggested process outlines 22 



Raw fish 22 



Fatty fish 22 



Enzymatic hydrolysis 23 



Bone feed product 23 



Fish oil 23 



Soluble concentrate 24 



Lean fish 24 



Press cake (fatty fish) 24 



Feed to digesters 25 



Enzymatic hydrolysis 25 



Processing 25 



Cost estimates 26 



Input data 26 



Summary of results 26 



Product characteristics and uses 27 



Characteristics 27 



Soluble product 27 



Partially soluble product 27 



Uses 27 



Status and future of biological FPC methods 28 



Summary 29 



Literature cited 30 



Appendix 32 



Figures 



No. Page 



1. Experimental system used for fish protein hydrolysis in 5-liter batches 6 



2. Fermentor used to prepare FPC in 20-gal hydrolysis batches 7 



3. Spray drying a partially soluble hydrolysate 9 



4. Yields of soluble solids from raw hake and cooked hake as a function of enzyme con- 



centration. Pancreatin, 5 hr at 45°C, no pH adjustment 14 



5. Soluble tryptophan recovery from raw hake and cooked hake as a function of enzyme 



concentration. Alcalase, 5 hr at 55°C and pH 9.5 15 



6. Percent solubilization versus pH for autolysis of red hake, 24 hr at 50°C 15 



7. Effect of pH of hydrolysis on the tryptophan concentration in soluble FPC 17 



8. Tryptophan concentration in soluble solids versus percent yield of solubles from enzy- 



matic hydrolysis of red hake 17 



9. Protein efficiency ratio (PER) versus chemical score for enzymatic hydrolysates of 



red hake and alewife 21 



10. PER versus Essential Amino Acid Index (EAAI) for fish protein hydrolysates 21 



11. Material balance, Run No. II-PC-2: totally soluble product from red hake 22 



12. Material balance, Run No. III-A-3: soluble product from alewife 23 



13. Material balance, Run No. III-APC-3: partially soluble product from alewife press cake 23 



14. Suggested process outline for soluble product from raw fish by enzymatic hydrolysis ... 24 



15. Suggested process outline for production of an FPC from fatty fish press cake by enzy- 



matic hydrolysis 25 



iv 



