Block 1. Experimental system establishment (month 0 -36)
This block will focus on development of experimental systems for detailed studies of lipid/protein oxidation and proteolysis in fish. The focus is on interactions between oxidised lipids/proteins with intact lipids/proteins in emulsions, liposomes, washed mince and whole muscle. All participants will use a set of reproducible analytical methods for measuring protein and lipid oxidation processes. This will allow generation of comparable data to use in the mathematical modelling. This block of work will involve 1.DIFRES, 18.Chalmers, 6.SINTEF and 31.NTNU.
Block 2. Modelling of oxidation in defined/real food emulsions and fish muscle (months 0 -54)
In this block of work, data on oxidation of marine lipids from block 1 and 4 will be analysed and mathematical models describing the oxidation kinetics in different systems containing marine lipids will be developed. This work will elucidate how lipid oxidation is dependent upon pro-oxidants. The mathematical models will be developed from relatively simple model systems to complex systems and might in future be used to design production methods for seafood with minimum lipid oxidation. 6.SINTEF and 45.MATFORSK will carry out the work.
Block 3. Relationship between protease activity and texture (months 0 -36)
Rapid assays of the main proteases present in fish muscle will be developed using fluorescent-labelled substrates in an ELISA plate type of assay. The proteases active post-mortem in fish and their correlation with texture will be determined. Differences in the rate/extent of post mortem softening between species will be utilised in the study. In model systems based on mixtures of fractions from different fish the regulation of the proteases will be studied. Moreover, the relationship between lipid/protein oxidation and protease activity will be studied. This work block will involve 62.INRA and 1.DIFRES.
Block 4. Interactions between reactants in experimental systems (months 0-54)
To obtain an understanding of protein/lipid oxidation mechanisms in fish products the interactions between the reactants responsible for the oxidative deterioration will be studied at the molecular level in simple model systems related to real foods. Interactions between proteins and lipids will be studied including oxidised hemoproteins, antioxidants, low molecular weight pro-oxidants. We will also study how oxidised lipids will interact with structural proteins to explain how this affects protein functional properties. This work block will involve 1.DIFRES, 18.Chalmers, 31.NTNU and 9.IFL.
Block 5. Effect of natural antioxidants in fish products (months 0 -54)
In this block of work, the antioxidant capacity of natural compounds (evaluated in model systems in block 4) will be investigated in frozen fish products and the effect of added antioxidants on the loss of endogenous antioxidants will be determined. Methodologies for antioxidants application will be tested in order to select the most efficient antioxidant. Selected antioxidants and antioxidant concentrations will be tested 11.IIM-CSIC, 18. Chalmers and 57. Unilever will carry out this work
Block 6. Effect of protein expression pattern on texture (months 19 -54)
The protein expression pattern will be used as a tool to find markers that can predict the quality (texture) of the final product from the raw material. Protein expression will be evaluated by proteome analysis using computer-aided image analysis in order to identify isoforms of muscle-expressed proteins. We will relate protein expression to protein and lipid oxidation This work block will involve 62.INRA and 1.DIFRES.