Fish Products and Byproducts Technology

Unit 4 - Fish preservation by smoking

4.2. Preservation by smoking
How smoking exerts preservative action?
Spoilage of fish can be reduced by reducing some of the important substances like water content, enzyme content and fat content.
The smoking process is effective in reducing the water by evaporation.
This occurs due to:

• The movement of the gases in the smoke over the surface of the fish
• Raising the temperature of the fish

The chemical components such as phenols and formaldehyde exist in the form of vapor in the smoke exert antioxidant and antibacterial activity.
In addition the smoking process results in the penetration of the chemicals into the fish and loss of water from the flesh. A layer is formed which reduces the effect of oxygen that enters the fish from the surrounding air. Therefore the rancidity of the fat is reduced. This layer is called “barrier layer”.