Effect of salmon plasma protein on Pacific whiting surimi gelation under various ohmic heating conditions

•Various ohmic heating rates effectively isolated enzyme activity in surimi.•Salmon plasma protein effectively inhibited protease in Pacific whiting surimi.•Salmon plasma protein increased gel strength during setting.•Salmon plasma protein is an effective inhibitor at low levels (0.5 g/100 g or less).

The effect of salmon blood plasma (SPP) on the gelation of Pacific whiting surimi under different ohmic heating conditions was investigated. SPP was found to significantly increase gel strength in gels heated ohmically to and held at 60° for 30 min followed by heating ohmically to 90 °C. SPP at a level of 1 g/100 g was also found to increase gel strength in gels held at 25 °C for 2 h prior to ohmic heating. This increase was not seen in gels where EDTA was added to inhibit the activity of endogenous transglutaminase (ETG). SPP also created a more pronounced setting effect as measured by dynamic rheology and SDS-PAGE. SPP was found to effectively inhibit protease activity through TCA-soluble peptide analysis. Scanning electron microcopy revealed a loosely arranged gel network caused by protease enzymes. It was reversed by the addition of SPP as well as setting at 25 °C due to ETG.