Quadratic relationship between early-post-mortem glycolytic rate and beef tenderness

Area of Science:

• Meat Science
• Animal Science
• Food Science

Background:

• Post-mortem (PM) meat quality, particularly tenderness, is influenced by early muscle metabolism.
• Controlling the rate of glycolysis is crucial for achieving desirable beef tenderness.

Purpose of the Study:

• To investigate the effect of low-voltage electrical stimulation (ES) timing on post-mortem glycolytic rate and beef tenderness.
• To determine the optimal electrical stimulation parameters for enhancing M. longissimus thoracis et lumborum (LTL) tenderness.

Main Methods:

• Electrical stimulation (ES) was applied at various stages of the slaughter process to beef carcasses.
• pH decline at 3 hours post-mortem (pH(3)) and Warner-Bratzler (WB) shear force were measured.
• Loin steaks were aged for 2, 4, 8, and 16 days PM.

Main Results:

• The rate of glycolysis, indicated by pH(3), was the primary factor determining LTL tenderness.
• Optimal tenderness was achieved when ES treatments resulted in a pH(3) of 6.0.
• ES applied after carcass splitting yielded more consistent pH(3) responses compared to other methods.
• Aging significantly improved the tenderness of steaks from leaner animals (bulls), making them comparable to those from fatter animals (steers) by 16 days PM.

Conclusions:

• Electrical stimulation is an effective method for controlling post-mortem glycolytic rate and enhancing beef tenderness.
• The timing of ES application is critical for achieving consistent and desirable meat quality outcomes.
• Aging plays a significant role in mitigating differences in tenderness between lean and fatter carcasses.