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Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Fisheries Sciences / Faculty of Fisheries Sciences >
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Preceding actin denaturation accelerates myosin denaturation in tilapia myofibrils in frozen storage
| Title: | Preceding actin denaturation accelerates myosin denaturation in tilapia myofibrils in frozen storage |
| Authors: | Thavaroj, Wichulada Browse this author | | Sakamoto, Mari Browse this author | | Konno, Yoshiko Browse this author | | Konno, Kunihiko Browse this author →KAKEN DB |
| Keywords: | Tilapia | | Myofibrils | | Actin denaturation | | Myosin | | Frozen storage |
| Issue Date: | Sep-2016 |
| Publisher: | Springer |
| Journal Title: | Fisheries science |
| Volume: | 82 |
| Issue: | 5 |
| Start Page: | 843 |
| End Page: | 850 |
| Publisher DOI: | 10.1007/s12562-016-1010-z |
| Abstract: | Myosin and actin denaturation (0.1 M NaCl, 20 mM Tris-HCl, pH 7.5) of tilapia myofibrils (Mf) during frozen storage at -10, -20, and -40 A degrees C was studied. Ca2+-ATPase inactivation was rapid at -10 A degrees C but very slow at -20 and -40 A degrees C. Myosin retained its solubility at 0.5 M NaCl even after Ca2+-ATPase inactivation. The amount of subfragment-1 generated from the Mf by chymotryptic digestion decreased with decreasing Ca2+-ATPase inactivation. The amount of rod produced in the frozen Mf remained at a high level, explaining the high salt solubility of myosin. Actin denaturation occurred in the Mf during freezer storage, as revealed by chymotrypic digestion patterns that showed a decreased actin content in the digest, and occurred much faster than Ca2+-ATPase inactivation. Analysis of tilapia meat during freezer storage revealed that Ca2+-ATPase inactivation was very slow in the frozen tissue and was ninefold slower at -10 A degrees C than at -20, and -40 A degrees C. Practically no actin denaturation occurred in the frozen meat. Based on these results, we conclude that native actin in frozen meat protects myosin from denaturation during the frozen storage period but that such protection by actin does not extend to Mf due to rapid actin denaturation. Consequently, the Ca2+-ATPase inactivation rate in Mf represents that of myosin itself-with no protection provided by actin. Therefore, the myosin denaturation rate obtained with Mf should not be used for frozen meat. Mf suspended in 0.1 M NaCl is not a suitable model by which to obtain the myosin denaturation rate in frozen fish meat. |
| Rights: | The final publication is available at www.springerlink.com via http://dx.doi.org/10.1007/s12562-016-1010-z. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/67081 |
| Appears in Collections: | 水産科学院・水産科学研究院 (Graduate School of Fisheries Sciences / Faculty of Fisheries Sciences) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 今野 久仁彦
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