Microbiological Studies on Aging of Intact and Excised Beef Muscle ¹

Area of Science:

• Meat Science
• Food Microbiology
• Food Safety

Background:

• Beef aging is crucial for tenderness and flavor development.
• Post-slaughter temperature management significantly impacts microbial growth and meat quality.

Purpose of the Study:

• To evaluate the effect of different aging temperatures and durations on beef spoilage.
• To determine the optimal post-slaughter handling for minimizing bacterial proliferation and spoilage.

Main Methods:

• Beef sides were subjected to four aging treatments: room temperature, refrigeration, a combination of room temperature and refrigeration, and extended low-temperature aging of excised rounds.
• Steaks and ground beef were prepared from aged sides and stored under retail conditions (5 C).
• Bacterial populations and spoilage indicators were monitored.

Main Results:

• Holding beef sides at room temperature (21-23 C) for 24 hours increased surface bacterial growth.
• Shortening high-temperature aging reduced bacterial populations on packaged beef.
• Excising muscle for low-temperature aging resulted in the highest bacterial loads and most rapid spoilage, exceeding that of 24-hour room temperature holding.

Conclusions:

• Extended high-temperature aging promotes microbial growth and spoilage in beef.
• Low-temperature aging of excised beef rounds is not recommended due to accelerated spoilage.
• Optimized aging protocols are essential for maintaining beef quality and safety.