Preserving the positive health effects in innovative pelagic fish products through the value chain

WP 1: Raw material, quality and health-related aspects: - The results show that freezing at -27 °C preserves the healthy marine lipids, vitamin D and low molecular weight metabolites such as free amino acids, IMP and Inosine in mackerel. - Changes in proteins take place during frozen storage between 1-7 month storage, however, more knowledge is needed on the relationship between protein oxidation during frozen storage and the quality parameters of muscle foods, especially in fish. - At chilled storage (+4°C) low molecular weight compounds relevant for food quality degrades into non-favorable compounds after 9 days. Therefore, the current results shows that preservation of mackerel by freezing is a better option compared to prolonged chilled storage when it comes to preserving health beneficial compounds. WP 2: Processing of herring and mackerel into high quality end products -traditional and modernized (novel) approaches: - This project shows that it is possible to produce marinated herring with lower NaCl content which have good quality and at the same time fulfils food safety requirements. Marinade with 25% total salt reduction where NaCl was reduced by 43% and replaced with 18% KCl showed the most promising results and can be recommended if it is desirable to reduce salt content in marinated herring products. - Studies on milder heat treatment of mackerel in tomato sauce (ie, <100 ° C) shows that protein oxidation occurs during the heating process, and to a greater extent at 80 and 90 ° C compared to 50 and 60 ° C. The sensory analysis shows that there are some challenges using milder temperatures in the production of canned mackerel in tomato sauce. WP 3: Market and consumer: - All four marinated herring product were liked. B0 got the lowest liking score, it is the sample with a salt reduction. The most liked was C0, this is the sample with both a salt reduction and a substitution of Na with K. - It is small differences between the different samples and it is mostly the appearance and texture attributes that deviates. The deviations are largest in the samples storage at 4°C. - There is no clear clustering of the consumers. There are a tendency towards C0 and R0. Based on the results it can be concluded that C0 can be an alternative to R0 (the reference sample). - The consumers knows already that fish is healthy therefore it is recommended that the communication strategy for the marinate herring with reduced salt content include the information on the benefit of lowering the health risk by lowering the salt content in the marinated herring product. WP 4: Mechanistic studies: Effect of new processes on protein and lipids in food: - The lipids in mackerel showed to be oxidatively stable during canning of mackerel. Addition of vit E could even more reduce the amount of secondary oxidation in the final canned products. The amount of vit D was also stable during the processing of mackerel into canned product. 100g of canned mackerel product without sauce would give 5 ?g vit. - Herring lipids were relatively oxidative stable during pre-marinating of herring. Reduction of sodium and replacement by potassium had no effect on the oxidation stability of lipids. Therefore, healthier (less sodium) marinated herring products could be produced without significant effect on the quality. The formation of free fatty acids developed during processing time and was not affected by studied amounts of salt in marinades. During marinating the vit D level in the herring stayed approx. 0,25 ?g vit D/g WW of herring.

Fatty fish such as mackerel and herring is an important part of a healthy diet. In addition to the well-known health beneficial long chain omega-3 fatty acids and vitamin D, these fish also contain monounsaturated fatty acids, proteins, di-peptides (carno sine, anserine) and free amino acids (taurine), which constitute tentative health promoting candidates. The project aims to investigate potential changes in well documented and potential health promoting compounds throughout early post-harvest handling an d storage of herring and mackerel (WP1), and also during classic processing operations like salting, marinating and canning (WP2). With the intention to maximize the healthiness of the end products, the same investigation will be carried out during novel/ modernized versions of classic salting, marinating and canning processes where e.g. the amount of salt has been reduced, the thermal regimes of the canning process has been modified and where natural antioxidants have been added. In order for high quality pelagic fish products to finally be consumed, detailed knowledge is however also needed about sensory quality and consumer acceptability (WP3). Mechanistic studies (WP4) will unravel how the individual process steps, with/without modifications affect ch anges in the compounds listed above, and how such changes are related to the sensory quality. The project will increase the knowledge about the interaction between different production processes and the stability of health beneficial compounds in pelagic fish, which will open up for targeted development of new products that could increase market shares. Based on the studies of consumer acceptability and sensory quality of the new herring and mackerel products in WP3, effective strategies for communication of health related benefits of mackerel and herring products to the consumers will be developed.