Effects of starch on rheological and gel properties of horse-mackerel surimi

To investigate the optimum kind and addition level of starch in order to improve the gel qualitiy of horse-mackerel surimi, effects of starch on the rheological and gel properties of horse-mackerel surimi were determined by rheological analysis, texture analysis, whiteness, water-holding capacity and microstructure. Two stages of changes of elastic modulus G' during heating process indicated two stages of thermal denaturation for horse-mackerel surimi by rheological measurement. The first change of G' appeared at the range of 20~57C (the G' was decreased with the in crease of temperature), and the second change of G' appeared at the range of 57~80C, the G' was increased with the increase of temperature which indicated that protein began to form gelation network. Addition of starch had positive effects on the elastic modulus G' of horse-mackerel surimi for starch molecules entangled much stronger. The gel strength of horse-mackerel surimi was increased with addition of starch. Tapioca starch and wheat starch had significantly positive effect on the gel properties of horse-mackerel surimi which was increased by 158% and 155%, with 4% of starch addition amount, respectively. Addition of starch increased the water-holding capacities of surimi, among which tapioca starch and wheat starch had the most significantly positive effect. Addition of starch increased the whiteness of surimi significantly, but the kind and addition of starch showed no significant difference.