Mechanism of Improvement Effect of Ascorbic Acid on the Thermal Gelation of Fish Meat

Abstract

The mechanism of improvement effect of ascorbic acid (AsA) against setting and kama-boko gels, which were the low temperature-and heat-induced gel of fish meat, respectively, was ex-amined by using frozen surimi (raw fish meat paste) of Alaska pollack. Adding 0.2% AsA re-sulted in the enhancement of the gel strength of heat-induced gel and uniformity of its micro-structure. The addition of AsA to crude actomyosin extracted from surimi promoted the polymer-formation during 40 or 90°C-incubation for 30min and resulted in decrease of surface hydropho-bicity and sulfhydryl groups. However, polymerization by AsA as described above could not be considered to depend on biochemical mechanism because the thermo-stability of crude actomyosin Ca- or Mg-ATPase activity was not enhanced by AsA. Moreover, crude actomyosin increased hydrophobicity by the addition of β-naphthoquinone-4-sulfonate formed the polymer by disulf-hydryl linkage earlier than native one. These results suggested the possibility that the polymer-formation by AsA was due to hydrophobic interaction, followed by the formation of disulfhydryl bonds between adjacent molecules.