Characteristics of surimi slurries and their films made from fish myofibrillar protein were investigated.
Films made from fish protein slurries consisting of Alaska pollock surimi (15% and 20%) and sodium
chloride (0%, 2%, and 5%) were either adjusted to different pH (7, 9, and 11) or mixed with sodium
tripolyphosphate (STP) (1.0%, 1.5%, and 2.0%). Increasing pH from 7 to 9 led to higher viscosity and exposed
sulfhydryl sites, while further pH increase 9–11) reduced the viscosity values and surface reactive
sulfhydryl groups. NaCl and STP addition decreased slurry viscosity. In most treatments involving the
roles of pH and either sodium chloride or sodium tripolyphosphate in film formation, sodium chloride
addition contributed to lower puncture strength and puncture distance. Meanwhile, there was a tendency
for elevated tensile strength and reduced elongation at break as sodium chloride concentration
was increased from 0% to 5%. Shifting pH to a more basic condition contributed to higher puncture
strength and distance. As STP concentration in the surimi slurries increased up to 2%, puncture and
tensile strength increased, but puncture distance and elongation at break decreased