Abstract
The tissues of skipjack (Katsuwonus pelamis) and red sea bream (Chrysophrys major) were fractionated into four components, extractives (Ex), sarcoplasmic protein (Sp-P), myofibrillar protein (Mf-P) and alkali-insoluble residue (R), to determine the contents of mercury and selenium in these components. The tissues used were the ordinary muscle and liver of both fishes and dark muscle of skipjack.
The total mercury in the ordinary muscle of both fishes was present in the Mf-P and Sp-P fractions, while the selenium was contained in the protein and Ex fractions. About 80% of the selenium in the liver of skipjack was found in Ex.
There was a linear relation between the total mercury content in ordinary muscle and that in Mf-P, and a similar tendency was observed in Sp-P. More mercury was incorporated in Mf-P than in Sp-P.
There was also a linear relation between the selenium content in ordinary muscle and that in the extract with phosphate buffer (Ex plus Sp-P), and a similar tendency was observed in Mf-P. The selenium content in the extract depended strongly on the selenium content in ordinary muscle.
Mercury removal from the ordinary muscle of both fishes by cysteine and cysteamine was also investigated.
Different proportions of the mercury were removed by the two compounds.
