Collaborations between the partners in the project have been further intensified in 2005. Four partners are now working on the evaluation of the same antioxidants in different systems and with different fish species. This will give a unique knowledge about the performance of these antioxidants in dependence of the complexity and composition of the food matrix. Interestingly, antioxidative effects of caffeic acid have been observed in both fish mince and in emulsions. The results obtained also indicate that the antioxidative efficacy is depending on many factors such as the fat content and the pH of the model system.
Data from washed fish muscle model experiments suggest that storage experiments at chilled temperatures can be used to predict haemoglobin catalysed oxidative deterioration of the lipids at lower temperatures. Similarly, chilled experiments with fish mince can be used to predict the effect of antioxidants at lower temperatures.
The mathematical models of lipid oxidation in liposomes and emulsions including work on the kinetics and oxygen mass balances are now able to describe the relationship between several parameters such as temperature, pH, oxygen level etc and the oxygen consumption rate.
Interesting relationships between the feeding regime, the texture and the cathepsin activity in rainbow trout have been found. In addition, cathepsin activity also seems to depend on the maturity of the trout, but there does not seem to be any significant correlation between maturity and texture.