Muscle of dark and normal beef differs metabolically.
L T Kirkpatrick1, J F M Gómez1, M Beline1
1Virginia Tech, School of Animal Sciences, Blacksburg, VA 24061, USA.
Meat Science
|October 1, 2023
Summary
Adverse handling reduces muscle glycogen, impacting beef quality. Atypical dark (AT) and dark-cutting (DC) beef exhibit higher oxidative properties, suggesting muscle oxidative capacity may predispose beef to dark coloration.
Area of Science:
- Meat Science
- Animal Science
- Biochemistry
Background:
- Adverse antemortem handling can lead to high ultimate pH and dark-cutting beef due to reduced muscle glycogen and altered postmortem energy metabolism.
- The specific relationship between atypical dark (AT) beef, its energy metabolism, and tissue characteristics remains incompletely understood.
Purpose of the Study:
- To investigate the tissue characteristics related to energy metabolism in normal, atypical dark (AT), and dark-cutting (DC) beef.
- To elucidate the underlying biochemical differences contributing to dark beef coloration.
Main Methods:
- Analysis of cattle harvested in the US and Canada.
- Classification of beef into normal (pH < 5.6), AT dark (pH 5.6-5.8), and DC (pH > 5.8) categories.
- Measurement of tissue characteristics including mitochondrial DNA content, oxidative enzymes, and myoglobin concentration.
Main Results:
- Atypical dark beef showed higher oxidative capacity compared to normal beef, with similar glycolytic potential and nucleotide abundance.
- Dark-cutting and AT dark beef exhibited significantly greater mitochondrial DNA content and oxidative enzyme activity than normal beef.
- Myoglobin concentration correlated with beef color classification.
Conclusions:
- Both dark-cutting (DC) and atypical dark (AT) beef possess inherently higher oxidative muscle characteristics.
- Increased muscle oxidative capacity may be a contributing factor to the development of dark beef coloration.
