College of Food Science and Technology, Henan Agricultural University, Zhengzhou 450002, China; Henan Key Lab of Meat Processing and Quality Safety Control, Henan Agricultural University, Zhengzhou 450002, China.
College of Animal Science and Technology, Henan Agricultural University, Zhengzhou 450002, China.
Food Chem. 2022 Dec 15;397:133797. doi: 10.1016/j.foodchem.2022.133797. Epub 2022 Jul 27.
Yak infraspinatus (IS), longissimus thoracis (LT), and semitendinosus (ST) muscles were used to explore relationships between myofiber types and postmortem redox characteristics. IS mainly consisted of myofiber type Ⅰ (49.2%), LT has a vast majority of type IIa (72.7%), while ST possessed a similar percentage of type IIa (44.7%) and IIb (51.5%). Compared with LT and ST, IS exhibited higher initial HO, myoglobin (T-Mb), and metmyoglobin (MetMb) contents that provoked severe protein oxidation despite higher endogenous antioxidative capacity (e.g., glutathione antioxidative system). Three muscles showed specificities in myofiber type composition and redox characteristics, which were strongly correlated. Specifically, type Ⅰ myofiber positively correlated with HO, T-Mb, and multiple antioxidase activity/content while negatively correlated with lipid peroxidation, MetMb, and lactic dehydrogenase activity; also, they tended to employ more SFAs in more intermuscular fat assembly. Overall, muscle-specific myofiber type/redox attributes required differentiated processing to prevent meat oxidation and produce standardized products.
牦牛的冈下肌（IS）、最长肌（LT）和半腱肌（ST）被用来探讨肌纤维类型和死后氧化还原特征之间的关系。IS 主要由肌纤维类型 I 组成（49.2%），LT 中绝大多数为 IIa 型（72.7%），而 ST 则具有相似比例的 IIa 型（44.7%）和 IIb 型（51.5%）。与 LT 和 ST 相比，IS 表现出更高的初始 HO、肌红蛋白（T-Mb）和变性肌红蛋白（MetMb）含量，尽管具有更高的内源性抗氧化能力（如谷胱甘肽抗氧化系统），但仍会引发严重的蛋白质氧化。三种肌肉在肌纤维类型组成和氧化还原特征上表现出特异性，这些特征之间存在强烈的相关性。具体来说，类型 I 肌纤维与 HO、T-Mb 和多种抗氧化酶的活性/含量呈正相关，与脂质过氧化、MetMb 和乳酸脱氢酶活性呈负相关；此外，它们倾向于在更多的肌间脂肪中使用更多的 SFAs。总的来说，肌肉特异性的肌纤维类型/氧化还原特性需要差异化的处理，以防止肉的氧化并生产标准化的产品。
