Correlation between skeletal muscle fiber type and free amino acid levels in Japanese Black steers
Correlation between skeletal muscle fiber type and free amino acid levels in Japanese Black steers
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DOI：
10.1111/asj.13185
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发表时间：
2019-04-01
影响因子：
2
通讯作者：
Mizunoya, Wataru
中科院分区：
文献类型：
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作者：
Mashima, Daisuke;Oka, Yoshiaki;Mizunoya, Wataru
游离氨基酸是肉类中促味剂和风味前体的重要组成部分。为了阐明肌纤维类型和游离氨基酸之间的相关性，我们测定了各种游离氨基酸和二肽的浓度在不同的肌肉组织（n = 21），收集了26个月龄的日本黑阉牛（n = 3）在死后2天。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS-PAGE）测定肌球蛋白重链（MyHC）、慢（MyHC 1）和快（MyHC 2）亚型的比例。采用高效液相色谱法测定游离氨基酸和二肽的含量。组织样本中的MyHC亚型组成各不相同。MyHC 1比例范围为6.9% +/- 3.9%至83.3% +/-16.7%。我们证实，有一个很强的正相关性之间的MyHC 1组合物和总游离氨基酸浓度，包括两个二肽。在测定的31种游离氨基酸和二肽中，有11种与MyHC 1组成呈显著正相关，5种与MyHC 1组成呈显著负相关。这些结果表明，高MyHC 1含量诱导牛肌肉中的高游离氨基酸含量，可能是因为更大的氧化代谢。这种高水平的游离氨基酸可能有助于肉类的强烈风味，富含慢收缩纤维。
Free amino acids are important components of tastants and flavor precursors in meat. To clarify the correlation between muscle fiber type and free amino acids, we determined the concentrations of various free amino acids and dipeptides in samples of different muscle tissues (n = 21), collected from 26-month-old Japanese Black steers (n = 3) at 2 days postmortem. The proportions of the myosin heavy chain (MyHC), slow (MyHC1) and fast (MyHC2) isoforms were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The contents of free amino acids and dipeptides were measured by high performance liquid chromatography (HPLC). The MyHC isoform composition varied among the tissue samples. The MyHC1 proportion ranged from 6.9% +/- 3.9% to 83.3% +/- 16.7%. We confirmed that there was a strong positive correlation between MyHC1 composition and total free amino acid concentrations, including those for two dipeptides. Among the 31 measured free amino acids and dipeptides, 11 showed significant positive correlations and five showed significant negative correlations with MyHC1 composition. These results suggest that a high MyHC1 content induces high free amino acid contents in bovine muscles possibly because of greater oxidative metabolism. This high level of free amino acids could contribute to the intense flavor of meat that is rich in slow-twitch fibers.