Quality improvement of mackerel surimi with NADPH-sulfite reductase from Escherichia coli

The application of NADPH-sulfite reductase, produced from Escherichia coli, on mackerel surimi was investigated. The activity of this reductase was ve ry stable. There was about 70%, 80%, and 90% activity left even after 8-wk storage at 25 degreesC and 12-wk storage at 4 or -30 degreesC, respectively . Increase in mackerel-surimi gel properties containing reductase was consi stent with the amounts of reactive sulfhydryl groups detected. SDS-PAGE ind icated that MADPH-sulfite reductase could reconstitute myosin heavy-chain a nd increase soluble actomyosin. From the data obtained, E. coli NADPH-sulfi te reductase effectively improved the gel properties of mackerel surimi.