Abstract
An optical method using murexide for determining calcium ion concentration at neutral pH could be applied to surimi and surimi paste; walleye pollack surimi used contained 2.76±0.17mM Ca2+.
Surimi pastes having different Ca2+ concentrations were prepared from the surimi by three different methods and incubated at 25°C prior to heating at 90°C. During the incubation, it was found that the gelation, an increase in cross-linked myosin heavy chains, and an incorporation of MDC into surimi paste occurred in a Ca2+-dependent manner. The maximal values for them were obtained in the presence of Ca2+ in the range of 2-5mM. Sr2+ and Mg2+ could not replace Ca2+ in the set gel formation.
It is concluded from all experimental results obtained that the major role of Ca2+ in set gel formation is the activation of TGase in the surimi paste.
