College of Engineering, Nanjing Agricultural University, Nanjing, Jiangsu 210031, China.
Department of Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA.
Poult Sci. 2018 Jul 1;97(7):2600-2606. doi: 10.3382/ps/pey107.
Woody breast (WB) is a myopathy of the Pectoralis major muscle in broilers that is characterized by increased hardness of the raw fillet. This defect increases economic losses due to associated decreased meat quality and the addition of training skilled laborers to identify problematic fillets. Therefore, the objectives of this study were to determine if compression force (CF) could be used as a non-invasive method of detecting WB and to assess changes in meat attributes during cold storage. Deboned fillets (n = 121) were collected from 8-wk-old broilers, and categorized as normal (NORM, n = 42), mild (MILD, n = 39), and moderate/severe (SEV, n = 40) for WB. Right fillet weight, drip loss, and CF of the cranial region were measured on the day of processing (day 0) and 1, 2, 3, 4, and 8 d of cold storage (4°C). Left fillets were sampled for sarcomere length (SL) and gravimetric fragmentation index (GFI) analysis following 1, 3, and 8 d of cold storage. Initial breast fillet weight, CF, cumulative drip loss, and SL increased as severity of WB category increased (P < 0.05). Compression force was highly correlated to WB severity (rs = 0.79). Compression force, SL, and GFI declined with storage time (P < 0.05), whereas cumulative drip loss increased (P<0.05). Cumulative drip loss, SL, and GFI had interactions between storage length and WB category (P < 0.05), where SEV generally changed more than NORM over time. The results of this study indicate that increased severity of WB fillets is associated with higher CF compared to normal fillets. Furthermore, there is a softening effect of the meat over time and data suggest that moisture (drip loss) and myofibril proteolysis (fragmentation) contribute to these changes. Using instrumental CF to assess fillet hardness can be used as a reliable tool to identify WB. However, adaptability in the commercial processing require additional studies prior to the incorporation into the processing plant for online grading purposes.
木胸（WB）是一种肉鸡胸大肌的肌病，其特征是生肉片的硬度增加。这种缺陷会因相关的肉质下降和需要培训熟练工人来识别有问题的肉片而导致经济损失增加。因此，本研究的目的是确定压缩力（CF）是否可作为一种非侵入性的检测 WB 的方法，并评估在冷藏过程中肉品属性的变化。从 8 周龄肉鸡中采集去骨肉片（n = 121），并根据 WB 的严重程度分为正常（NORM，n = 42）、轻度（MILD，n = 39）和中度/重度（SEV，n = 40）。在加工当天（第 0 天）和冷藏第 1、2、3、4 和 8 天测量右片的重量、滴水损失和颅区 CF。在冷藏 1、3 和 8 天后，对左片进行肌节长度（SL）和重量损失分析。随着 WB 严重程度的增加，初始胸肉片重量、CF、累积滴水损失和 SL 增加（P < 0.05）。CF 与 WB 严重程度高度相关（rs = 0.79）。随着储存时间的延长，CF、SL 和 GFI 下降（P < 0.05），而累积滴水损失增加（P<0.05）。累积滴水损失、SL 和 GFI 在储存长度和 WB 类别之间存在交互作用（P < 0.05），其中 SEV 随时间的推移比 NORM 变化更大。本研究结果表明，与正常肉片相比，WB 肉片的严重程度越高，CF 越高。此外，随着时间的推移，肉的软化效应明显，数据表明水分（滴水损失）和肌原纤维蛋白水解（碎裂）导致了这些变化。使用仪器 CF 来评估肉片的硬度可以作为一种可靠的工具来识别 WB。然而，在将其纳入加工厂进行在线分级之前，还需要在商业加工中进行适应性研究。
