Soglia Francesca, Iaccheri Eleonora, Laghi Luca, Ragni Luigi, Suñer Pedro José Fito, Petracci Massimiliano
Interdepartmental Centre for Agri-Food Industrial Research, Alma Mater Studiorum, University of Bologna, Cesena, Italy; Department of Agricultural and Food Sciences, Alma Mater Studiorum, University of Bologna, Cesena, Italy.
Institute of Food Technology Food UPV, Universitat Politecnica de Valencia, Valencia, Spain.
Poult Sci. 2025 Jan;104(1):104595. doi: 10.1016/j.psj.2024.104595. Epub 2024 Nov 26.
Dielectric Spectroscopy (DS) and TimeDomain-Nuclear Magnetic Resonance (TD-NMR) were exploited to investigate water and solid dynamics in chicken's Pectoralis major muscles having macroscopically normal appearance (N) and affected by Wooden Breasts (WB) abnormality. 147 PMM were collected and classified as macroscopically normal (N) (N=74) or Wooden Breast (WB) (N=73) based on their visual appearance and manual palpation. Protons' T (transverse relaxation time), and dielectric properties were carried out. The dielectric constant ( [Formula: see text] and the loss factor ( [Formula: see text] of γ relaxation of WB samples was significantly higher than the one of N samples ( [Formula: see text] 59.8 and [Formula: see text] 18.3), while the WB revealed a low relaxation frequency (1.5 E+09) compared to N samples (1.7 E+09). WB showed a higher dielectric constant of relaxation and thus polarizability mainly due to free water, and lower relaxation frequency imputable to a more complex solid structure. This was confirmed by TD-NMR, evidencing a significant increase in the relative intensity of the proton population ascribable to the extra-myofibrillar water (32.9 vs. 21.5%; P<0.001) along with a reduction of the one occupying the intra-myofibrillar spaces (62.0 vs. 75.4%; P<0.001). These outcomes may be ascribed to the re-organization of the skeletal muscle structure associated with the onset and progression of the WB abnormality.
利用介电谱（DS）和时域核磁共振（TD-NMR）研究了外观宏观正常（N）和受木胸（WB）异常影响的鸡胸大肌中的水和固体动力学。收集了147块胸大肌，并根据其外观和手动触诊将其分类为宏观正常（N）（N = 74）或木胸（WB）（N = 73）。测量了质子的横向弛豫时间（T）和介电特性。WB样品的γ弛豫的介电常数（[公式：见正文]）和损耗因子（[公式：见正文]）显著高于N样品（[公式：见正文] 59.8和[公式：见正文] 18.3），而与N样品（1.7 E + 09）相比，WB的弛豫频率较低（1.5 E + 09）。WB显示出较高的弛豫介电常数，因此主要由于自由水导致的极化率较高，而较低的弛豫频率归因于更复杂的固体结构。TD-NMR证实了这一点，表明归因于肌原纤维外水的质子群体的相对强度显著增加（32.9对21.5％；P <0.001），同时占据肌原纤维内空间的质子群体相对强度降低（62.0对75.4％；P <0.001）。这些结果可能归因于与WB异常的发生和发展相关的骨骼肌结构的重组。
