Initial Chilling Rate Effects on Bacterial Growth on Hot-Boned Beef ¹

Area of Science:

• Food Science
• Microbiology
• Meat Science

Background:

• Hot-boned beef processing offers potential advantages but requires careful control of microbial growth.
• Bacterial contamination and proliferation are critical concerns for meat safety and quality during post-mortem handling and storage.

Purpose of the Study:

• To determine the optimal chilling rate for hot-boned beef to inhibit bacterial proliferation.
• To assess the impact of chilling times on the microbiological and sensory quality of hot-boned beef.

Main Methods:

• Hot-boned beef cuts were chilled to 21°C at varying intervals (3, 5, 9, 12 hours) post-carcass removal.
• Vacuum storage at 2.2°C for 14 or 21 days, followed by 3-day display at 2.2°C.
• Bacterial enumeration (indicator organisms, potential pathogens) and sensory evaluations (color, odor) were performed.

Main Results:

• Cuts chilled to 21°C within 3–9 hours exhibited lower bacterial counts compared to those chilled in 12 hours.
• Faster chilling rates (3-5 hours) resulted in bacterial loads comparable to conventionally chilled beef.
• Slower chilling rates (9-12 hours) correlated with higher counts of coliforms, *Staphylococcus aureus*, *Clostridium perfringens*, and fecal streptococci.

Conclusions:

• Hot-boned beef must be chilled to 21°C within 3 to 9 hours to maintain good bacteriological condition.
• Chilling rates significantly influence the growth of indicator organisms and potential pathogens.
• Achieving rapid chilling is essential for ensuring the safety and quality of hot-boned beef products.