JPI HDHL: Innovative processing to preserve positive health effects in pelagic fish products

The aim of the project is to develop a comprehensive toolbox of optimized existing and novel technologies for developing healthy, high quality, safe and sustainable fish products from pelagic fish species. Pelagic fish is rich in omega-3 lipids (EPA and DHA) with documented beneficial effect against coronary heart diseases, easily digestible proteins; vitamins (E and D). However, during processing; high temperatures, exposure to air, prooxidative components (like heme), may lead to loss or destruction of the valuable healthy components i.e. oxidation of omega-3 fatty acids and proteins. During raw material storage, microbial contamination can lead to formation of histamine. Therefore, optimal processing technologies to transfer healthy pelagic fish raw material into healthy and safe pre-prepared food products is needed. A consumer survey has been carried out in four countries showing differences in preferences for convenient fish products. Only about half the consumers believed in the need to increase their fish consumption. Differences between the different countries were observed regarding how the consumers perceived pelagic fish products. This should be taken into account when developing new pelagic fish products. Studies of different methods to prolong the shelf-life of mackerel has been carried out. Superchilling of mackerel is promising with regard to microbial stability and freshness indices and can double the shelf life. However, the method needs to be optimised to increase water holding and texture. Frozen storage is a good method for long term preservation of pelagics, but changes in the proteins are observed after a storage time of around 6-8 months. Several studies on sous vide treated mackerel showed that sous vide treatment resulted in good microbial quality, but lipid oxidation increased with storage. This results in loss of the valueable fatty acids as well as loss of quality. Addition of antioxidants is therefore necessary. High Pressure Processing at pressure up to 200 MPa can be used to prolong the shelf life of mackerel, but higher pressures had negative influence on the raw material quality. The microbial shelf life and changes in lipid stability of fish cakes with 50% mackerel show that the use of herbs as antioxidants gives some challenges for the microbial stability due to microbial flora of the herbs. Model products (canned products in Poland and both canned products and fish cakes with 25% and 50% mackerel in Norway) were tested by consumer panels. The results show that fish cakes with up to 50% mackerel had an acceptance not lower than the currently produced white fish cakes.

Forbrukerundersøkelsen viste signifikante forskjeller i forbrukerpreferanser. Forbrukertesten på modellproduktene viste at det er mulig å lage fiskekaker med opptil 50% makrell som har god forbrukeraksept. Lovende prosesseringsteknologier er studert - superkjøling, sous vide, høytrykksprosessering (HPP) mm. Superkjøling gir en dobling av holdbarheten sammenlignet med lagring på is, noen utfordringer med råstoffkvaliteten ble avdekket. Sous vide behandling med bruk av antioksidanter gir produkter med god holdbarhet. Høytrykksprosessering kan brukes til å forlenge holdbarhet, men for høye trykk reduserer råstoffkvaliteten. Det er oppnådd økt forståelse av mekanismene som er involvert i endringene i kvalitets- og stabilitetsparameterne for de ulike prosesseringsmetodene. Dette gjelder særlig mer kunnskap om endringer i proteiner, lipider og lavmolekylære metabolitter og sammenheng med endringer i kvalitetsparametre. Nye analytiske metoder er studert og utprøvd.

Increased awareness of the diet's importance for overall health, increase the demand for products with enhanced healthiness having good sensorial properties. Pelagic fish is rich in omega-3 lipids (EPA and DHA) with documented beneficial effect against coronary heart diseases, easily digestible proteins; vitamins (E and D). Therefore pelagic fish is a valuable food resource in a healthy diet. However, during processing; high temperatures, exposure to air, prooxidative components (like heme), may lead to loss or destruction of the valuable healthy components i.e. oxidation of omega-3 fatty acids and proteins. During raw material storage, microbial contamination can lead to formation of histamine. Therefore, optimal processing technologies to transfer healthy pelagic fish raw material into healthy and safe pre-prepared food products is needed. The ProHealth project will develop a comprehensive toolbox of optimized existing and novel technologies which will enable the food industry to provide healthy and safe pelagic fish products for the European consumers. This will be done by increasing knowledge on consumer preferences in choosing processed fish products which can be used by the fish processing industry in developing new and improved food matrices and novel convenient products. Knowledge on consumer acceptance of the model products with preserved health effects will indicate possibilities to create healthy food with good sensory properties. The knowledge can be used by the industry to develop new functional foods.