|Determination of ammonia in dressed thornback ray (Raja clavata L.) as a quality test|
Vyncke, W. (1978). Determination of ammonia in dressed thornback ray (Raja clavata L.) as a quality test. Journal of Food Technology 13(1): 37-44
In: Journal of Food Technology. Blackwell Science Ltd: Oxford. ISSN 0022-1163, more
Raja clavata Linnaeus, 1758 [WoRMS]; Marine
The sensory determination of ammonia in raw, steamed and boiled ray wings using a scoring system appeared to be a valuable method of quality assessment. The borderline of acceptability was reached after 10 (±1) days in ice. A combination of the steaming and boiling tests (with addition of acetic acid and salt) was useful to confirm definite spoilage or to indicate the approach to the borderline of acceptability.The chemical determination of ammonia appeared to be a useful objective method in addition to the organoleptic tests.Thornback ray was borderline at a concentration of 60–70 mg N. From the other related parameters determined (urea, pH, redox potential, total bacterial count, a-amino nitrogen) only pH appeared to be of value.