In 2012, the Ministry of Food, Agriculture and Livestock issued a Communiqué on Sensory Properties of Fisheries Products and Total Volatile Basic Nitrogen Limits (Communiqué no: 2012 / 73). This communiqué describes the sensory properties and total volatile basic nitrogen limits of fishery products.

According to the Communiqué, if there is any suspicion that the raw fish products are fresh during sensory examinations (freshness criteria for Annex 1 Fisheries products), or if it is determined that the TVB-N limits are exceeded as a result of chemical controls (Total volatile basic nitrogen acceptable in Annex 2 Fisheries products, TVB) (N-limits), these products are not suitable for consumption.

For the control of the TVB-N limits, the method of distillation of the deproteinized extract with perchloric acid in the annex of the notification is used (determination of total volatile basic nitrogen (TVB-N) concentration in Annex 3 Fishing products).

In the said communiqué, there are routine methods for controlling total volatile basic nitrogen, TVB-N limits.

The most important cause of deterioration in fish, bacterial activities. There are millions of microorganisms in the gills, stomach and intestine systems and surfaces of fish in general. Immediately after catching fish, these bacteria reach the blood vessels and fish flesh and start to produce odor. The bacteria that cause deterioration in fish living in cold waters are generally gram negative bacteria. The number of gram-positive bacteria is also high in fish living in hot waters.

TVB-N gives the total amount of volatile basic nitrogen, which begins to accumulate in the tissues with deterioration during storage of the fish. The TVB-N value is used to determine whether deterioration has started in frozen, dried or salted seafood products stored or stored for long periods of time.

Total volatile basic nitrogen determination (TVB-N) studies on fishery products are carried out in authorized laboratories within the scope of chemical food analyzes. In these studies, standards and test methods published by domestic and foreign organizations are followed.