Quantitative estimation of dark muscle content in the mackerel meat paste and its products using antisera against myosin light chains

Based on the high level of extractability of myosin subunits (light chains), even after prolonged heat treatment of muscle, a new method to evaluate the dark muscle content in the fish meat and products of mackerel is proposed. Tissue-specific rabbit antisera with myosin light chains (Al from ordinary muscle and D I from dark muscle) from mackerel Scomber japonicus were obtained. Mackerel meat paste (surimi) was dissolved in 8 M urea containing 1% SDS, and diffused on agar plates containing antiserum against Al or DI by single radial immunodiffusion (SRID). The results obtained showed that the area of halos formed in the plates! was quite proportional to the content of dark muscle.