Kimura Noriyuki, Nishimura Nana, Iwama Nagako, Aihara Yoshito, Ogawa Yasuki, Miyaguchi Yuji
College of Agriculture, Ibaraki University, Ami-machi, Ibaraki, Japan.
Beef Cattle Laboratory, Ibaraki Prefectural Livestock Research Center, Hitachiomiya-shi, Ibaraki, Japan.
Anim Sci J. 2017 Oct;88(10):1615-1622. doi: 10.1111/asj.12806. Epub 2017 May 8.
The thermal property of bovine intramuscular adipose tissue (IAT) was evaluated using differential scanning calorimetry (DSC) and compared with the melting point temperature (MP) of the fat extract of IAT, which was measured using the slip point method. The beef samples were classified according to the beef marbling score (BMS). Beef with a high BMS contained less protein than that with middle or low BMS. Beef with a high BMS contained significantly more fat than that with a low BMS (P < 0.05). The endothermic point temperature (EP) of IAT, measured by DSC, was significantly higher than the MP of IAT fat (P < 0.05). The EP showed no significant difference among the three marbling grade groups. Although the MP was correlated with the monounsaturated fatty acids (MUFA) content of IAT (R = 0.505), there was no correlation between the EP and the MUFA (R = 0.040). However, the EP of IAT treated with collagenase was relatively highly correlated with the MP (R = 0.655). Thus, these results suggested that DSC analysis would give us the practical thermal information regarding the melt-in the-mouth of beef such as the gelatinization of collagen, along with the melting of fat in IAT.
使用差示扫描量热法（DSC）评估牛肌肉内脂肪组织（IAT）的热特性，并将其与采用滑点法测量的IAT脂肪提取物的熔点温度（MP）进行比较。牛肉样品根据牛肉大理石花纹评分（BMS）进行分类。高BMS的牛肉比中BMS或低BMS的牛肉含有更少的蛋白质。高BMS的牛肉比低BMS的牛肉含有显著更多的脂肪（P < 0.05）。通过DSC测量的IAT的吸热点温度（EP）显著高于IAT脂肪的MP（P < 0.05）。EP在三个大理石花纹等级组之间没有显著差异。虽然MP与IAT的单不饱和脂肪酸（MUFA）含量相关（R = 0.505），但EP与MUFA之间没有相关性（R = 0.040）。然而，用胶原酶处理的IAT的EP与MP的相关性相对较高（R = 0.655）。因此，这些结果表明，DSC分析将为我们提供有关牛肉入口即化的实际热信息，如胶原蛋白的凝胶化以及IAT中脂肪的熔化。
