Effects of low-frequency electrical stimulation on beef tenderness

Area of Science:

• Meat science
• Food technology
• Muscle physiology

Background:

• Electrical stimulation is used to tenderize meat.
• The mechanisms of meat tenderization via electrical stimulation are not fully understood.
• Rapid pH decline and muscle fiber damage are potential factors.

Purpose of the Study:

• To investigate the role of rapid pH decline versus muscle fiber fracture in meat tenderization.
• To determine the effect of low-frequency (2 Hz) versus normal-frequency (60 Hz) electrical stimulation on beef tenderness.
• To assess the impact of accelerated glycolysis on meat eating quality.

Main Methods:

• Early post-mortem beef sides were subjected to 2 Hz, 500 V electrical stimulation with mild/delayed chilling.
• Paired control sides received no stimulation.
• Other sides were treated with 60 Hz, 500 V electrical stimulation.
• Muscle glycolysis, pH decline, fiber integrity, and tenderness were assessed.

Main Results:

• Low-frequency stimulation (2 Hz) accelerated glycolysis but did not cause fiber rupture, resulting in tougher steaks.
• Normal-frequency stimulation (60 Hz) caused extensive fiber fracturing and significant tenderization.
• Accelerated glycolysis, independent of fiber damage, negatively impacted eating quality.

Conclusions:

• Meat tenderization by high-voltage electrical stimulation is primarily due to muscle fiber fracturing, not rapid pH decline.
• Low-frequency stimulation, while promoting glycolysis, hinders tenderization by avoiding fiber damage.
• The benefits of electrical stimulation in preventing cold-shortening are outweighed by negative effects on eating quality when glycolysis is excessively accelerated.