輪切りにした魚体に割裂荷重を加えて, さらに縦割り切断加工を施し, 凍結魚をフィレーの状態に加工する方法について検討を行った. 内臓を含む魚体腹部及び内臓を含まない魚体尾部に対して-190～-20℃の凍結温度で割裂試験を行い, 縦割り切断加工が可能になる温度条件を調べた. その結果、腹部試料では-120～-60℃範囲で, 脊椎骨・神経棘と内臓を同時に分離する縦割り切断が可能であった. 尾部試料では-140～-80℃範囲で, 脊椎骨・神経棘・血管棘を同時に分離する縦割り切断が可能であった.We have previously shown the feasibility of a round slice-cutting method for small fish such as mackerel and saury, where a three point bending load is applied to frozen fish for cutting. The present study examines a filleting method in which a cylinder splitting load is applied to frozen round sliced fish to further cut the fish lengthwise. Splitting tests were conducted at the freezing temperature range from -190 to -20°C using abdominal test pieces (viscera included) and tail test pieces (no viscera) as the samples to determine the optimum temperature where lengthwise cutting could be successfully achieved. In the abdominal test pieces, lengthwise cutting that simultaneously separated the vertebra, neural spine and viscera from the fillet became possible within the range from -120 to -60°C. In the tail test pieces, lengthwise cutting that simultaneously separated the vertebra, neural spine and viscera from the fillet became possible within a range from -140 to -80°C
