In sifts activity of intestinal chymotrypsin in sugar-salted whole herring during cold storage was evaluated by analysing changes in the low-molecular-weight nitrogen fraction when a specific inhibitor was added. Addition of chymostatin (0.01 mM) to sugar-salted herring gave 100% inhibition of chymotrypsin activity compared to sugar-salted herring without chymostatin. Inhibition of chymotrypsin did not affect the profile of low- molecular-weight peptides analysed by capillary zone electrophoresis, but resulted in 22% lower content after 26 weeks of storage. Inhibition of chymotrypsin resulted in 17% lower content of free amino acids. The relative amount of single free amino acids was unaffected by the presence of inhibitor, except for valine, leucine, isoleucine, methionine, phenylalanine and tyrosine, which were formed in lower relative amount. Removal of intestines (gutted herring) and thereby all intestinal proteolytic activity did not change the free amino acid profile, except for the concentration of histidine which decreased more when intestines were present. (C) 2000 Society of Chemical Industry.
|Journal||Journal of the Science of Food and Agriculture|
|Publication status||Published - 2000|