Mitochondrial function in turkey skeletal muscle—impact on meat quality

Abstract

1. M. iliotibialis (MIT) and M. pectoralis (MP) of the BUT Big 6 and Kelly BBB turkey were characterised with respect to physical properties, mitochondrial function, metabolic state, morphology and meat quality. 2. Mitochondrial enzyme activity and respiration rates in MP declined with increasing age while glycolytic enzyme activity remained nearly constant. 3. There were no major differences between BUT Big 6 and Kelly BBB with respect to histological, histochemical or biochemical variables. In spite of the greater adult weight of BUT Big 6, body proportion was equal in both strains. 4. In agreement with the histochemical findings MIT showed higher oxidative capacities, while glycolytic enzyme activity was higher in MP. 5. Pyruvate was the best substrate for oxidative phosphorylation in MIT, but not in MP. Pyruvate dehydrogenase (PDH) activity was up to 15 times less in MP and blood lactate was correlated with intramuscular pH. 6. Turkey breast muscle was restricted in its ability to oxidise pyruvate, especially in those animals that tended to develop intramuscular acidosis post mortem. 7. It is concluded that the in vivo metabolic environment results in acidosis and impaired meat quality, at least in turkey M. pectoralis.

Mitochondrial respiratory and antioxidative enzyme activities in turkey meat

“…Using the skinned fibre technique, Opalka et al (2004) also showed significantly higher MRAs in the MIL in comparison with the MPS, and this difference is related to the higher percentage of oxidative FTO and STO fibres in the leg muscle and the accompanied increasing oxidative metabolism, as already discussed in the previous chapter.…”

“…Determination of the MRA is a method to investigate oxygen consumption of the tissue and has been analysed in muscle/meat samples from poultry (Tang et al, 2002;Opalka et al, 2004;Bottje and Carstens, 2009). Using the skinned fibre technique, Opalka et al (2004) also showed significantly higher MRAs in the MIL in comparison with the MPS, and this difference is related to the higher percentage of oxidative FTO and STO fibres in the leg muscle and the accompanied increasing oxidative metabolism, as already discussed in the previous chapter.…”

“…The biochemical differences between the muscles seem to be related to the different muscle structures of the MPS and MG. In turkeys, the MPS only consists of FTG fibres (Opalka et al, 2004;Branciari et al, 2009). Leg muscles such as the MG also have fast-twitch oxidative (FTO) and STO fibres (Papinaho et al, 1996;Remignon et al, 2000).…”

“…Leg muscles such as the MG also have fast-twitch oxidative (FTO) and STO fibres (Papinaho et al, 1996;Remignon et al, 2000). Also taking into account the results of Opalka et al (2004), which presented a higher oxidative energy metabolism in the MIL, and the present results with a higher MRA of the MG, it could be concluded that shortly after slaughter the glycogen in the MG is degraded to a higher extent via citrate cycle and ETC in comparison with the MPS accompanied with lower lactate accumulation and higher pH, as shown by Fernandez et al (2001). The EC values determined 24 h p.m. support this assumption, as this parameter is negatively correlated with the pH (Werner et al, 2008).…”

The relationship of pork longissimus muscle pH to mitochondrial respiratory activities, meat quality and muscle structure

“…Investigation in broiler and turkey meat also showed no impact of a lower pH 20 min p.m. on the Pyr/ Mal-MRA results (Opalka et al, 2004;Werner et al, 2011). In all these studies, MRA was analysed with permeabilised muscle fibres.…”