AgResearch Ltd., Ruakura Research Centre, Hamilton, New Zealand.
Meat Sci. 2012 Dec;92(4):681-6. doi: 10.1016/j.meatsci.2012.06.023. Epub 2012 Jun 23.
The objective of this study was to determine effects of pre rigor stretching on beef tenderness development. Beef loins (M. longissimus dorsi; n=24) were assigned to either stretching or non-stretching treatments and aged for 14 days at -1.5 °C. Sarcomere length, shear force, water-holding capacity and proteolysis were determined for the loins at 1, 7 and 14 days of ageing. Stretching increased the length of the loins by 33% resulting in a trend of increasing sarcomere length (P=0.19). However, no significant differences for shear force values, purge, drip and cooking losses between treatments were found. Shear force values decreased with ageing times (P<0.05). Western blot assay found that stretching did not affect the extent of desmin degradation. The findings from the present study suggest that pre rigor stretching with the current increase in length will not contribute to tenderness improvement of the beef loins.
本研究旨在确定僵直前拉伸对牛肉嫩度发育的影响。将牛肉里脊（背最长肌；n=24）分配到拉伸或非拉伸处理中，并在-1.5°C下老化 14 天。在老化 1、7 和 14 天时，对里脊进行肌节长度、剪切力、持水力和蛋白质水解的测定。拉伸使里脊的长度增加了 33%，导致肌节长度呈上升趋势（P=0.19）。然而，处理之间的剪切力值、渗出、滴水和蒸煮损失没有显著差异。剪切力值随老化时间的增加而降低（P<0.05）。Western blot 分析发现，拉伸不会影响结蛋白降解的程度。本研究的结果表明，目前增加长度的僵直前拉伸不会有助于牛肉里脊嫩度的改善。
