The raw materials from headed and gutted salmon, which in recent years have become the basis for the fish processing industry in Poland, are particularly suited for more profitable exploitation. In recent years there has been a steady increase in imports of salmon into Poland for use by the processing industry. Each tonne of fish regardless of how it is processed generates 120 kg of heads, 100 kg of spines, 40 kg of raw scraps resulting from trimming the fillets with skin, and 60 kg of raw or smoked skins. In 2010 imports of fresh gutted salmon into Poland amounted to approximately 106 thousand tonnes, of which 100 thousand tonnes were used for processing. The amount of waste raw material thus amounted to 12,000 tonnes of heads, 10,000 tonnes of spines, 4,000 tonnes of raw scraps resulting from trimming the fillets with skin, and 6,000 tonnes of skins with the subcutaneous meat and fat tissue.
Many uses for salmon processing left-overs
In total, 32 thousand of tonnes of raw materials containing considerable amounts of valuable substances were produced. These include 5,120 tonnes of protein, 7,040 tonnes of fish oil, and 960 tonnes of mineral substances. Salmon skins, constituting about 19% of the waste, can be used as the raw material for the production of oil, fish collagen, and fish gelatine that can be used in a variety of applications. However, salmon waste raw materials can be used in the production of higher value semi-finished products such as fish oil (a dietary supplement); natural mineral preparations; gelatine for human consumption or non-food purposes; and fragmented salmon meat for human consumption.
The University of Technology and Life Sciences in Bydgoszcz and the Sea Fisheries Institute in Gdynia started a pilot project with the objective of extracting quality products from waste generated by the salmon processing industry. The project was financed by the Agency for the Restructuring and Modernisation of Agriculture. Under the project a new system for obtaining semi-finished and finished products from salmon waste will be developed for testing on a commercial scale. The new system will conform to all the currently valid hygiene and food safety requirements.
Maximise returns by proper handling of raw material
The main project goals were to improve the economic effectiveness of the use of fish waste raw material. The project subjected the raw material to chemical and microbiological analysis and determined procedures for handling the waste that conform to sanitary and hygienic regulations. In addition the project determined how to use each fraction of the waste most rationally.
Preliminary results suggest that the waste material from fresh salmon processing gives significant amounts of fish oil, of fat-soluble vitamins, and may be used for the production of natural mineral preparations rich in calcium, phosphorus, magnesium, potassium, selenium, and other mineral. This suggests that salmon waste can indeed be used for the production of products that represent a higher value than fish meal. In Poland the presence of large salmon processing plants will secure the raw material supply and the waste is expected to be fresh and of high quality. With its large population and thriving economy Poland could also be a market for dietary supplements.