Carcass weight-dependent chilling rate modulates early postmortem metabolism and lean color development in beef

Area of Science:

• Meat Science
• Animal Science
• Biochemistry

Background:

• Standard chilling protocols may negatively impact smaller beef carcasses.
• Accelerated chilling can affect postmortem metabolism, pH decline, and lean color.
• Atypical dark-cutting (ATDC) defects are linked to chilling and metabolic processes.

Purpose of the Study:

• To investigate if carcass weight-dependent chilling rates influence early postmortem metabolism.
• To determine if altered metabolism contributes to darker lean color associated with ATDC.
• To explore the relationship between chilling rate, metabolism, and meat quality defects.

Main Methods:

• Compared chilling rates, muscle temperature, pH, and metabolites in heavy (HW) and light-weight (LW) beef carcasses (n=44).
• Assessed longissimus lumborum temperature, pH, and metabolites from 0 to 24 hours postmortem.
• Evaluated protein abundance, color (L* values), and tenderness (shear force) at different time points.

Main Results:

• Light-weight carcasses chilled faster, showing lower muscle temperatures and darker lean color (lower L* values).
• LW carcasses maintained higher early glycogen and glucose-6-phosphate concentrations.
• Increased shear force was observed in LW carcasses at 1 day, but tenderness normalized with aging.

Conclusions:

• Carcass weight variations significantly impact chilling rates and early postmortem metabolic progression.
• Accelerated chilling in lighter carcasses is a potential mechanism contributing to ATDC-like phenotypes.
• Understanding these weight-dependent chilling effects is crucial for mitigating meat quality defects.