Effects of Rigor Mortis on Gel‐forming Properties of Surimi and Unwashed Mince Prepared from Tilapia

Quality of surimi and unwashed fish (tilapia, Areochromis aureus) mince was investigated as affected by development of rigor mortis in fish prior to processing. Significantly higher protein content and yield, reduced cook loss, and enhanced gel‐forming ability and protein ex‐tractability were associated with surimi produced from pre‐rigor fish. Gels prepared from unwashed minced muscle exhibited less cook‐loss pre‐rigor, but stage of rigor had little effect on gel Theological properties and protein extractability. Thermal rigidity scanning and differential scanning calorimetry showed substantially higher rigidity values and enthalpies of denaturation, respectively, for surimi prepared from pre‐rigor fish, but no effect on transition temperatures due to stage of rigor.