Effect of Hardness of Plastic Fat on Structure and Material Properties of Fish Protein Gels

Textural modification of fish protein gels by incorporation of plastic fat was investigated by examining the effect of the physical properties of fat on the structure and the material properties of protein gels. Material properties of fat‐containing protein gels were influenced largely by fat distribution pattern which was, in turn, affected by fat hardness. Both compressive and shear forces reached their maximum when fat of 1.8 cm–1 hardness index (HI) was added at a level of 15% (fat/muscle). Addition of medium hard fat (0.54–0.78 cm–1 HI): (1) prevented a sponge‐like texture development by improving freeze‐thaw stability; (2) increased plastic deformation, thus making cooked gels less rubbery; (3) overcame the weakening of texture caused by cooking at the critical zone (60–70°C); and, (4) minimized the variations in textural strength resulting from cooking. Copyright © 1981, Wiley Blackwell. All rights reserve