Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria, Australia.
Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Victoria, Australia.
Meat Sci. 2021 Sep;179:108521. doi: 10.1016/j.meatsci.2021.108521. Epub 2021 Apr 10.
The effect of thermal protein denaturation on the structure and quality of muscles of different fibre types is not well understood. Unaged masseter (100% type I fibres) and cutaneous trunci (93% type II fibres) muscles (N = 10) were assessed for their characteristics, protein denaturation, cooking loss, Warner- Bratzler shear force (WBSF) and shrinkage after heating at 50 °C - 85 °C with a rate of 5 °C/ min. Raw masseter had a higher pH, collagen and water content, shorter sarcomere, comparable fibre diameter, and shorter and wider fragments upon homogenization, than cutaneous trunci. In cutaneous trunci, at 55 °C - 60 °C, the lower transition temperature of myosin and the greater cumulative enthalpy resulted in greater cooking loss in muscle cuboids, and greater transverse, longitudinal and volume shrinkage in fibres and fibre fragments, than in masseter. Protein denaturation explained 71% variability in fibre fragment volume and 58% in cooking loss of both muscles, as well as 47% variability in WBSF of masseter.
热蛋白质变性对不同纤维类型肌肉的结构和品质的影响尚不清楚。未老化的咀嚼肌（100%的 I 型纤维）和腹外斜肌（93%的 II 型纤维）（N=10）用于评估其特性、蛋白质变性、蒸煮损失、华纳-布拉泽尔剪切力（WBSF）和在 50°C-85°C 以 5°C/分钟的速度加热后的收缩率。生咀嚼肌的 pH 值、胶原蛋白和水分含量较高，肌节较短，纤维直径相当，均质化后片段较短较宽，而腹外斜肌则相反。在腹外斜肌中，在 55°C-60°C，肌球蛋白的较低转变温度和更大的累积焓导致肌肉立方体的蒸煮损失更大，纤维和纤维片段的横向、纵向和体积收缩更大，而在咀嚼肌中则相反。蛋白质变性解释了两种肌肉纤维片段体积变化的 71%和蒸煮损失的 58%，以及咀嚼肌 WBSF 变化的 47%。
