1Department of Agricultural and Food Sciences,Alma Mater Studiorum - University of Bologna,47521 Cesena (FC),Italy.
2Department of Nutrition and Food Technology,Faculty of Agriculture and Veterinary Medicine,An-Najah National University,P.O. Box 7,Nablus,Palestine.
Animal. 2018 Oct;12(10):2198-2204. doi: 10.1017/S1751731117003469. Epub 2018 Jan 8.
In the past decades, the intense selection practices carried out in order to develop fast growing and high breast-yield turkey hybrids profoundly modified the muscle physiology leading to the development of growth-related alterations and muscular abnormalities. White striations of variable thickness have been particularly observed on the ventral surface of Pectoralis major muscle belonging from heavy male turkeys since several years. However, although the effects of white striping (WS) have been extensively studied on broilers, this condition was not considered as a main quality issue by both turkey producers and meat industry. Thus, this study aimed at evaluating whether the occurrence of WS in heavy male turkeys affects the quality traits and technological properties of meat to the same extent previously observed for broilers. In two replications, 72 Pectoralis major muscles were classified as: normal (NORM), moderate WS (MOD) and severe WS (SEV) cases. The whole muscle was weighed and cut in order to assess colour, ultimate pH, water holding (drip and cooking losses) and binding (marinade uptake) capacities, NMR relaxation properties, shear force as well as proximate composition of meat. The Pectoralis major muscles affected by WS (both moderate and severe cases) exhibited a one-fifth increased weight in comparison with their NORM counterpart. However, the occurrence of WS only partially affected the proximate composition of the meat. In detail, although moisture, collagen and protein contents did not differ among the groups, if compared with NORM, higher lipid levels were found in SEV muscles, whereas MOD had intermediate values. On the other hand, both MOD and SEV exhibited lower ash content. Despite these variations in proximate composition, both water holding and binding capacities of turkey breast meat were not affected by WS. Indeed, quality traits of raw (pH, colour, cooking losses and shear force) and marinated (uptake, cooking losses and shear force) meat as well as water distribution within the muscle tissue did not differ between NORM and WS cases. Overall, if compared with broilers, WS only marginally affected quality traits of turkey breast meat. It might thus be hypothesised a diverse specie-specific physiological response to the pressure in muscle tissue induced by the selection in turkeys that, although analogously led to the occurrence of WS, results in limited effects on meat quality.
在过去的几十年中，为了培育快速生长和高产乳肉的火鸡杂种，人们进行了强烈的选择实践，这深刻地改变了肌肉生理学，导致了与生长相关的改变和肌肉异常的发展。多年来，人们一直在观察来自大型雄性火鸡的胸大肌腹侧表面出现的厚度不同的白色条纹。然而，尽管白色条纹（WS）的影响已在肉鸡上得到广泛研究，但火鸡生产者和肉类行业都没有将这种情况视为主要的质量问题。因此，本研究旨在评估大型雄性火鸡中 WS 的发生是否会对肉质的质量特性和技术特性产生与之前在肉鸡上观察到的相同程度的影响。在两个重复实验中，将 72 个胸大肌分为：正常（NORM）、中度 WS（MOD）和严重 WS（SEV）病例。对整个肌肉进行称重和切割，以评估颜色、最终 pH 值、水分保持（滴水和蒸煮损失）和结合（腌制液吸收）能力、NMR 弛豫特性、剪切力以及肉的近似成分。受 WS 影响的胸大肌（中度和严重病例）的重量比其 NORM 对应物增加了五分之一。然而，WS 的发生仅部分影响了肉的近似成分。具体而言，尽管水分、胶原蛋白和蛋白质含量在各组之间没有差异，但与 NORM 相比，SEV 肌肉中的脂质水平较高，而 MOD 则处于中间水平。另一方面，MOD 和 SEV 均表现出较低的灰分含量。尽管在近似成分上存在这些差异，但 WS 并未影响火鸡胸肉的水分保持和结合能力。事实上，生肉（pH 值、颜色、蒸煮损失和剪切力）和腌制肉（吸收量、蒸煮损失和剪切力）以及肌肉组织内水分分布的质量特性在 NORM 和 WS 病例之间没有差异。总体而言，如果与肉鸡相比，WS 仅略微影响火鸡胸肉的质量特性。因此，可以假设火鸡中由于选择而导致的肌肉组织压力引起的物种特异性生理反应不同，尽管同样导致 WS 的发生，但对肉质的影响有限。
