The effect of previous storage condition on the diffusion and contribution of digestive proteases in the ripening of marinated Baltic herring (Clupeaharengus)

Abstract

The objective of this study was to investigate the effect of 1–5 days of cold storage (1.8 °C) of whole fresh herring (CS) and frozen-thawed 3 days at −20 °C herring (F + CS, CS + F) on marinating process. During cold storage proteases from the digestive tract diffused into meat, the fastest for chymotrypsin > esterase and amidase trypsin > carboxypeptidase-A. Digestive proteases in meat have started proteolysis of meat, assisted the release of cathepsins D > L > B from lysosomes and participated in the marinades ripening. High digestive protease activity in the meat resulted in full ripeness of the marinades, in contrast to the control sample without protease diffusion. Esterase trypsin and carboxypeptidase-A activity in meat correlated the strongest with protein hydrolysis products (PHP) and the sensory evaluation of the marinades. The best marinades were obtained from herring assessed up to 16–18 points in Quality Index Method during cold storage of the whole herring. Freezing the fillets after cold storage of whole herring (CS + F) had no disadvantage effect on marinades flavour, in contrast to freezing the whole herring before cold storage (F + CS), where an increase of chymotrypsin and decrease of carboxypeptidase activity resulted in an increase in bitters PHPs content. Diffusion of digestive proteases during cold storage of herring makes it possible to produce high sensory quality marinades from cheaper by 20–30% herring of low technological suitability.