Effect of Soy Protein Isolate and Wheat Fiber on the Texture and Freeze-Thaw Stability of Lean Fish Mince

The effects of cyclic freezing and thawing upon the quality of frozen fish mince were studied. The effectiveness of combined use of Soy Protein Isolates SPI) (2%) and Wheat Fiber (WF) (2%) were investigated with respect to cryoprotective properties and textural changes in fish frozen mince. The changes in texture and water holding capacity of fish mince after two freeze-thaw cycles were assessed using Texture Analyzer (TA.XT Plus) and sensory analysis. Cooking loss upon freeze-thaw cycles was also determined. No cryoprotectant and texture modification effect of the wheat fiber was observed. The addition of soy protein isolate and/or wheat fiber significantly reduced cooking loss after two freeze-thaw cycles (p < 0.05). Combined use of soy protein isolate (2%) and wheat fiber (2%) showed added benefit in reducing expressible moisture compared to using SPI alone (2%) even the differences were not significant (p > 0.05) and provided synergistic effect in texture modification (p < 0.05) and also reduced freeze-contraction of myofibrils after two freeze-thaw cycles according to the results of scanning electron micrographs. This cryoprotectant combination can be applied to fish mince for the improvement of their texture and frozen storability.