504 



MARINE PRODUCTS OF COMMERCE 



The water phase, separated by the first centrifugal, contains particles of liver 

 tissue, some vitamins adsorbed on the soaps, and some oil; this mixture is called 

 "wash oil." The vitamins in the "wash oil" are usually recovered by mixing it with 

 a low-vitamin edible oil at 175° F (80° C), and by centrifuging. The washing 

 process may be repeated until the vitamin A potency is so slight that it is no 

 longer profitable to repeat the washing (Young and Robinson, 1938). 



It is obvious that many variations are possible in the above procedures. Some 

 oil processors have found by experience that certain modifications require varying 

 conditions. For reasons which can be determined at the individual plant the 

 steps in the process are adjusted to the conditions. 



A modification of the alkali process (patented by Herbert Hempel in 1939) 

 involves use of a different type of alkali to neutralize the fatty acids which de- 

 velop as the livers decompose. The alkalies suggested were borax, trisodium 

 phosphate, and ammonium hydroxide. Specific adjustments of the pH of the 

 livers to insure complete neutralization of the fatty acids is recommended. These 

 procedures are similar except for this difference in alkalies. 



Enzyme- and Alkali-Digestion Process. This process involves the use of both 

 alkalies and peptization to complete the digestion of the liver cells for the release 

 of the oil. Brocklesby and Green (1934 and 1937) suggest the following pro- 

 cedure : 



The livers are minced or disintegrated and a volume of water equal to that of 

 the livers is added, together with sufficient hydrochloric acid to give the mixture a 

 pH of 1.2 to 1.5. A pepsin solution containing 0.5 per cent by weight of the livers 



Steam Inlet 



Maintair sufficient atmosphere 

 of steam u/ithin Disintegrator 

 and Prebreaker Feeder to exclude 



air - minimizing oxidation and 



emulsion factors. 



Suppiy Pi/fffp 



M*6NETIC STARJH 

 FOR FEEDER 



LOADTROL 



{Courtesy Edw. Renneburg and Sons Co.) 



Fig. 23-3. The disintegrator finds many uses of value in the liver oil and the fish 



meal plant. 



