Dielectric spectroscopy and TD-NMR investigation for assessing water solid dynamics in normal and wooden breast chicken

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’ T2 (transverse relaxation time), and dielectric properties were carried out. The dielectric constant (εjavax.xml.bind.JAXBElement@505de580=62.0) and the loss factor (εjavax.xml.bind.JAXBElement@5f7055d2=19.7) of γ relaxation of WB samples was significantly higher than the one of N samples (εjavax.xml.bind.JAXBElement@19dcbba7=59.8 and εjavax.xml.bind.JAXBElement@65a4247=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.