Suitability of Japanese codling as a raw material for surimi-based products revealed by primary sequence analysis of myosin heavy chain and thermal gel properties

Complementary DNA encoding a part of myosin heavy chain was cloned from fast skeletal muscle of Japanese codling Physiculus japonicus . Japanese codling, a frequent catch off the Pacific coast of northeastern Japan, is a typical underutilized fish species, especially in summer. Phylogenetic analysis of the deduced amino acid sequence of Japanese codling myosin heavy chain loop 2 region revealed that this fish belongs to a group comprising white croaker Pennahia argentata and walleye pollack Gadus chalcogrammus , which are commonly used as raw materials for surimi-based products. Thus Japanese codling meat was considered a promising candidate ingredient for surimi-based products. Salt-ground meat was prepared from Japanese codling in the presence of 0.5 M NaCl and subjected to a two-step heating procedure: pre-heating at 15–70 °C for 30 min, and secondary heating at 85 °C for 20 min. Thermal gels with a maximum breaking strength of > 10 N were produced by this process. The breaking strength was comparable to that of white croaker and walleye pollack. On the basis of the phylogenetic analysis of myosin heavy chains, and the properties of the heat-induced surimi gel, we conclude that Japanese codling is a promising raw material for the production of surimi-based products.