(I) Analytical biochemistry and data analysis: Development of instrumental methods (acoustical and vision-based) for determination of chemical and physical quality parameters. Water distribution and mobility in fish muscle measured by low-field NMR. Enzymatic analysis. Multivariate data analysis in fisheries research. Mathematical transformations and simulations. (II) Enzymatic quality deterioration of fish during storage: TMAO degradation: enzyme properties. Lipid and protein hydrolysis and oxidation. Enzyme activities of predictive value. Effect of freezing and processes in unfrozen water.