Study on the delay effect of discoloration of fish meat by NAD degradation during frozen storage

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K07826
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Food science
• Research Institution: Kindai University
• Principal Investigator: Tsukamasa Yasuyuki 近畿大学, 農学部, 教授 (90298943)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 冷凍 / 魚肉 / メト化 / NAD / ATP / ｐH / 解凍

Outline of Final Research Achievements

Optimum condition of temperature treatment on the meat of B1 frozen skipjack was studied. The temperature treatment at -5 ºC for 24 h was the optimum condition to suppress the pH decrease and formation of metmyoglobin during chilled storage. We also examined the effects of temperature treatment had on pH, as well as changes in NAD+ and ATP concentrations. The meat of eight different species of fish was studied. The fish were prepared by instant killing, followed by quick freezing and stored at -50 °C. A temperature treatment of -7 °C for 24 h before thawing showed a significant reduction of NAD+ in the meats of the longtooth grouper, threeline grunt, Japanese jack mackerel, white trevally, and bastard halibut and a significant reduction of ATP in the meats of the Japanese jack mackerel, and white trevally. A significant effect on the reduction of pH changes was observed in the meats of the threeline grunt, Japanese jack mackerel, and white trevally when stored at 10 °C.

Free Research Field

水産化学

Academic Significance and Societal Importance of the Research Achievements

魚は品質劣化が速いため,冷凍は有効な貯蔵手段であり，高品質を維持する冷凍技術も開発されている。しかし，冷凍肉を解凍，冷蔵した際に起こる品質劣化を防ぐ技術も必要とされる。解凍前に短期間，温度を上げる温度変更処理はその有効な対策と考えられる。本研究では，冷凍カツオ肉の最適な処理条件が-5℃で24時間であることを確認した他，クエ、マアジ、ヒラメ、ハマチ、マダイなど8魚種を対象に,-7℃で24時間の温度変更処理を施し，解凍後の品質との関係が深い，NAD，ｐH，ATP含量の変化が一様ではなく，マアジ，シマアジで有効な結果が得られた反面，マダイやハマチにこの条件は適さないことを明らかにした。