Table 17. — Cost estimates for biological and press cake (fatty fish) biological processes, 



200 operating days per year. 



Process 



Capacity, tons/day 



Total capital costs 



Oil, tons/yaar 



Value @ $80/ton 



Bone feed, tons/year 



Value, @ $60/ton 



Total by-product value, $/year 



Total operating cost, $/year . . 

 Net cost, $/year 



Dry concentrate, tons/year . . . 

 Assigned cost, $/ton 



Est. production cost, cents/lb . 30.0(! 



19.7^ 



ig.g?- 



12.8«( 



for enzymatic products would be increased about 

 25% at 50 tons/day and about 40% at a 200 

 tons/day plant capacity. (The same increase in 

 cost per pound represents a smaller percentage 

 of the higher cost at 50 tons/day.) 



The production costs listed in Table 17 in- 

 clude amortization of capital costs but do not 

 include marketing costs and profit margins. 

 Selling prices might be in the range of 30 to 50% 

 higher. 



PRODUCT CHARACTERISTICS 

 AND USES 



Characteristics 



Soluble product. — Totally soluble products, 

 prepared by spray drying of clarified hydroly- 

 sates, are fine powders of low bulk density. They 

 are more or less hygroscopic and should be stored 

 in sealed containers. 



Soluble FPC prepared from hake are oflf-white 

 to light yellow in color. Odors are mildly cheese- 

 like and in some products somewhat fishy. Taste 

 is moderately salty and cheeselike with a slightly 

 fishy aftertaste. The soluble product prepared 

 from alewife was light yellow in color and had 

 a malty, slightly fishy odor. Taste was some- 

 what fishy with a slightly bitter aftertaste. 



A typical soluble FPC prepared at pH 8.5 will 

 contain 78 to 80% crude protein, about 0.5% 

 lipids, about 16% soluble ash, and less than 5% 

 moisture. Based on chemical scores, isoleucine 

 is usually the limiting amino acid for products 



prepared with alkaline proteases. Methionine 

 is next limiting for alewife products and tryp- 

 tophan for hake products. 



Partially soluble product — Products that are 

 50 to 70 ';r water-soluble have been prepared by 

 autolysis of raw fish and also by enzymatic hy- 

 drolysis of press cake. An FPC prepared from 

 alewife press cake had an orange-brown color 

 and a sweet, fish meal odor. Although it had 

 a good protein efficiency ratio, it had a very high 

 lipid content and a definitely fishy taste. A 

 spray-dried hake autolysate was a gray powder 

 containing 12% lipids and had a less fishy taste 

 and odor. 



The amino acid patterns of the partially sol- 

 uble products were in general similar to those 

 of the raw fish. Protein efficiency ratios for all 

 of the products were essentially equivalent to 

 that of casein. 



Uses 



Totally soluble protein hydrolysates of whole 

 fish can be used in food products such as soups 

 and beverages where solubility is desirable if a 

 bland flavor is not required. Nutritionally, they 

 are particularly eflfective as a wheat supplement. 

 Aside from human food items they might also 

 find use as a milk replacer in calf feeding ration, 

 etc., where a cheap product with low fat content 

 is needed. Changes in processing conditions or 

 raw material may be required to produce a 

 blander soluble product suitable for human bev- 

 erage formulations. 



27 



