65% – 72% PROTEIN CONTENT FISH MEAL (FEED GRADE). !!. In the UK & Turkey the term fish meal means a product obtained by drying and grinding or otherwise treating fish or fish waste to which no other matter has been added. The term white fish meal is reserved for a product containing not more than 6 per cent oil and not more than 4 per cent salt, obtained from white fish or white fish waste such as filleting offal. These are semilegal definitions, and for convenience fish meal can be defined as a solid product obtained by removing most of the water and some or all of the oil from fish or fish waste. Fish meal is generally sold as a powder, and is used mostly in compound foods for poultry, pigs and farmed fish; it is far too valuable to be used as a fertilizer.
No cheap, completely safe method of preservation has yet been found. Refrigeration is not usually economic, and the known chemical methods of preservation have some disadvantages. Sodium nitrate with formaldehyde is very effective, but unless its addition is very carefully controlled poisonous nitrosamines can be formed when the nitrite reacts with small amounts of trimethylamine in the fish; for this reason nitrite is not used in the UK and also in Turkey. Formaldehyde alone is quite effective in keeping the fish firm enough for processing; it is most useful for species like sand eels that rapidly become semiliquid soon after catching. Although the addition of about 0-2 per cent by weight of formaldehyde is often enough to provide the required toughening effect, the preservative effect is small at this dilution, and more formaldehyde may make the fish too tough to process.