Nutritional value of fish visceral meals

Abstract

AbstractViscera from white fish and herring were azeotropically dried and their amino acid compositions were compared with those of an azeotropically dried whole herring and of four commercial fish meals. The gut meals were similar in composition to the whole herring meal and the commercial meals, though the herring gut meals contained appreciable quantities of nitrogen not identified in the Moore & Stein amino acid analysis.An attempt was made to relate the nutritive value of the azeotropically dried meals to their amino acid compositions.The nutritive values of the meals for rats when given as the sole protein source were apparently related to their histidine content, and in tests with chicks, in which the meals were given with a cereal‐based ration, nutritive quality was related to total lysine content.The visceral meals were relatively rich in soluble nitrogen, and in a meal manufactured during warm weather there was considerable autolysis to free amino acids. Autolysis and bacterial spoilage may lower the histidine content of visceral meals with possible production of toxic substances. With efficient processing fish viscera could provide protein‐rich concentrates of fair quality.Some technological problems are discussed.