Oxidative stress and postmortem meat quality in crossbred lambs
Nicolas J Herrera1, Nicolas A Bland1, Felipe A Ribeiro1
1Department of Animal Science, University of Nebraska-Lincoln, Lincoln, NE 68583-0908, USA.
Journal of Animal Science
|May 15, 2021
Summary
Lipopolysaccharide (LPS) administration increased lamb body temperature and altered muscle gene expression related to oxidative stress. This induced oxidative stress did not negatively impact fresh meat color but enhanced tenderness early postmortem.
Area of Science:
- Meat Science
- Animal Science
- Biochemistry
Background:
- Oxidative stress is a significant factor influencing meat quality and shelf-life.
- Understanding the biological mechanisms behind oxidative stress in livestock is crucial for improving meat production.
- Lipopolysaccharide (LPS) is a potent inducer of inflammatory and oxidative responses.
Purpose of the Study:
- To investigate the effects of varying levels of LPS-induced oxidative stress on fresh lamb meat quality.
- To analyze the impact of LPS on inflammatory responses, muscle gene expression, and meat characteristics.
- To evaluate the interplay between oxidative stress, aging, and retail display on meat attributes.
Main Methods:
- Crossbred lambs were injected with saline (control), 50 ng/kg BW LPS (LPS50), or 100 ng/kg BW LPS (LPS100) over a 9-day period.
- Rectal temperatures were monitored to assess inflammatory response.
- Muscle samples (Longissimus lumborum) were collected for RNA analysis, and loins were aged (1 or 14 days) before fabrication into chops.
- Chops were subjected to retail display (0 or 7 days), and quality parameters including Warner-Bratzler shear force (WBSF), color (L*, a*, b*), pH, calcium concentration, and proteolysis were measured.
Main Results:
- LPS administration elevated lamb rectal temperatures and upregulated RNA pathways associated with oxidative stress generation.
- A trend towards improved tenderness (lower WBSF) was observed in LPS50 treated lambs at 1 day postmortem, with greater troponin T degradation.
- Aging significantly improved tenderness, increased pH and calcium concentration, and enhanced proteolysis.
- Retail display increased meat discoloration, while LPS-treated lamb chops exhibited altered color values (higher a* and L*).
- No significant differences were found in proximate composition, fatty acid profile, or isoprostane content.
Conclusions:
- Induced oxidative stress via LPS in lambs did not detrimentally affect fresh meat color.
- LPS treatment may modulate biological pathways influencing muscle stress response, apoptosis, and enzymatic processes, potentially improving early postmortem tenderness.
- Aging remains a critical factor in enhancing meat tenderness and quality attributes.
