Source of smoked salmon may influence its quality.

There are a variety of factors that influence the quality and yield of cold smoked salmon. Such factors include the smoking process itself, how the salmon are fed and their origin.

Consumption of smoked salmon in the European Union is estimated at 88,500 tons per year. France, Great Britain and Denmark are the largest producers of this product in the European Union, while the main European producers of the raw material, fresh Atlantic salmon, are Norway, Scotland, Ireland, the Faroe Islands and Iceland.

In the past, the raw material has been frozen wild salmon with a low fat content. Today the main source is farmed fresh salmon. There was a need to analyze how this change in raw material, as well as the smoking process, could influence the quality and yield of smoked salmon.

Six research institutes from France, Iceland, Norway and Spain worked together for three years to come up with answers to these questions. Researchers concluded that a high number of fat deposits and a high fat content in raw fillets related to a higher liquid loss during processing, except for frozen and dry salted fillets. However, the number of fat deposits appears to have a greater impact than the actual fat content itself.

In addition, scientists determined that the type of food the fish consumed as well as the smoking parameters greatly influenced yield and quality. Fillets with a high fat content, greater than 10%, gave a higher yield and were less sensitive to freezing. Fatty pieces required a lower smoking temperature, which improved quality.

Farmed salmon had a higher percentage of polyunsaturated fatty acids (PUFAs) and a lower n-3 to n-6 ratio than did the ocean-produced salmon. This may give nutritional advantages to farmed salmon. It's possible to regulate the fatty acid composition through the selective feeding of the farmed fish.

FYI: There is considerable evidence that fish and fish oils are beneficial to the health of the heart, reduce the risk of cancer and benefit mental health. The active components of fish oils are eicosapentaenoic acid (EPA), a PUFA with 20 carbon atoms in its backbone, and docosahexaenoic acid (DHA), a PUFA with 22 carbon atoms. Both are members of the omega-3 group of essential fatty acids. EPA and DHA are found exclusively in marine animals. Fatty fish, such as herring, sardines, salmon and fresh tuna, are the best sources.

Further information. Hannes Hafsteinsson, Center of Food Technology, Technological Institute of Iceland (IceTec), Keldnaholt, 112 Reykjavik, Iceland; phone: [phone]; fax: [phone]; email: [e-mail].