Chemical Indicator of Fish Freshness: TVB-N Determination

Fish and fishery products are highly sensitive to storage conditions and temperature fluctuations due to their natural characteristics. As spoilage progresses, changes occur not only in the appearance and odor of the product but also in its chemical composition.

One of the important parameters used to monitor these changes is TVB-N (Total Volatile Basic Nitrogen) determination. TVB-N represents the total amount of volatile basic nitrogen compounds formed during the spoilage of fish tissue and helps assess the freshness of the product.

How Is Freshness Loss Monitored Chemically?

As storage time increases, the breakdown of nitrogen-containing compounds in fish tissue accelerates due to enzymatic and microbial activities.

During this process, ammonia, trimethylamine, and other volatile basic nitrogen compounds may be formed. TVB-N determination is based on measuring the total amount of these compounds.

Therefore, TVB-N analysis is an important indicator for monitoring chemical changes associated with the degradation of proteins and nitrogen-containing compounds in fish tissue and evaluating product freshness.

How Do Cold Chain Disruptions Affect TVB-N Results?

Temperature control is critical for maintaining the quality of fishery products.

Disruptions in the cold chain, storage at unsuitable temperatures, or extended storage periods may accelerate microbial and enzymatic activities. As a result, an increase in volatile basic nitrogen compounds may occur.

Therefore, TVB-N determination is an important analytical parameter, particularly in raw material acceptance, storage monitoring, shelf-life studies, and quality control applications.

Which Regulations and Methods Apply to TVB-N Analysis?

In Türkiye, TVB-N criteria are regulated under the Turkish Food Codex Communiqué on Sensory Characteristics and Total Volatile Basic Nitrogen Limits for Fishery Products (Communiqué No. 2012/73).

The analytical method is defined in Annex 3 of the Turkish Food Codex Communiqué No. 2012/73.

TVB-N determination is based on the separation of volatile basic nitrogen compounds from the sample and their quantification using a titrimetric method.

There is no single general limit applicable to all fishery products. The regulation establishes different maximum limits for specific fish species and product groups.

Therefore, accurately identifying the fish species when requesting an analysis is essential for evaluating the results against the relevant regulatory criteria.

Both the analytical method used and the regulatory category of the product must be considered when interpreting the results.

Accredited TVB-N Analysis at Bilim Laboratories

At Bilim Laboratories, we perform TVB-N (Total Volatile Basic Nitrogen) determination in fish and fishery products under TÜRKAK accreditation in accordance with the ISO/IEC 17025 standard.

For more information about our accredited TVB-N analysis services, sample requirements, analysis prices, and turnaround times, please contact Bilim Laboratories.