|Determination of the ammonia content of fish as an objective quality assessment method|
Vyncke, W. (1970). Determination of the ammonia content of fish as an objective quality assessment method. Mededel. Fac. landb. wet. Rijksuniv. Gent 35(4): 1033-1046
In: Mededelingen van de Faculteit Landbouwwetenschappen. Rijksuniversiteit Gent. Faculteit Landbouwwetenschappen: Gent. ISSN 0368-9697, more
In order to evaluate the possibilities of the determination of ammonia as an objective quality assessment method for fish and crustaceans a series of storage experiments was carried out on cod (Gadus morhua L), redfish (Sebastes marinus L), plaice (Pleuronectes platessa L) , herring (Clupea harengus L) , spurdog (Squalus acanthias L), spotted dogfish (Scylliorhinus canicula L), Norway lobster ( Nephrops norvegicus L) and shrimp (Crangon vulgaris Fabr.). Besides ammonia, total volatile basic nitrogen (TVN) and trimethylamine (TMA) were determined.The experiments showed the value of the test to be limited for bony fish. Wlth cod, redfish and herring, ammonia values increase only slightly during storage in ice and do not follow the organoleptic judgment. Only with plaice a better agreement was noted but even in that case, TVN determinations gave a better picture of the decrease in freshness.With cartilaginous fish, however, the determination of ammonia is of value and is in good agreement with the organolepticjudgment. Finally, experiments on the two species of crustaceans showed that the determination of ammonia has about the same usefulness as the TVN test, and can be considered as an alternative method.