塩漬条件が凍結解凍したマアジ肉の離水に及ぼす影響 Effects of soaking conditions on water release from thawed jack mackerel meat

即殺直後のマアジを用いて，塩漬条件が塩漬魚肉を凍結解凍した際に生じる離水に及ぼす影響を検討した。浸漬液の NaCl 濃度が 0.5 M 以上で離水率の増加は認められず，少なくとも魚肉中の NaCl 濃度が 0.25 mol/kg 以上になると，離水率は水分に影響されず一定の低い値を示した。筋肉ホモジネートにおいて，筋原線維タンパク質（Mf）の溶解と保水力の上昇とが認められた NaCl 濃度は，0.2～0.4 M 付近と一致していた。以上より，NaCl による Mf の溶解作用が魚肉の保水力を向上させ，離水を抑制していることが示唆された。<br>

  The effects of soaking conditions on released water of thawed jack mackerel <i>Trachurus japonicus</i> meat after soaking, freezing, and thawing were studied using a jack mackerel immediately after being killed. The water release rate for previously soaked thawed meat did not increase when the NaCl concentration of the soaking solution was 0.5 M or higher. When the NaCl concentration in the jack mackerel meat was 0.25 mol/kg or higher, the water release rate was not affected by moisture but showed a constant low value. In muscle homogenate, a rise in water-holding capacity matched the solubilization of myofibrils (Mf) by NaCl in the vicinity of 0.2 to 0.4 M. Glucose, which is not able to solubilize Mf, did not show improvement in the water-holding capacity. Therefore, it is suggested that a dissolution action of Mf by NaCl improves the water-holding capacity of the soaked, frozen, and thawed meat and suppresses water release.<br>