Microbial Growth in Carcasses and Boxed Beef During Storage

Area of Science:

• Food Microbiology
• Meat Science
• Food Safety

Background:

• Canadian beef is a significant food commodity.
• Understanding microbial contamination during beef processing and distribution is crucial for food safety.
• Previous studies have highlighted the importance of packaging methods on microbial load.

Purpose of the Study:

• To evaluate the microbial contamination levels of fresh western-Canadian beef carcasses and boxed beef upon arrival at an eastern-Canadian terminal.
• To compare microbial profiles between different beef product formats (carcass portions vs. boxed beef).
• To identify predominant microbial species associated with each product type.

Main Methods:

• Sampling of beef carcasses (front and rear portions) and boxed beef (heat and clip-sealed) over a 12-month period.
• Enumeration of total microbial counts, Lactobacillus, total coliforms, and fecal coliforms.
• Isolation and identification of predominant microbial species from samples.

Main Results:

• Total microbial counts ranged from log10 6.28 (carcass front) to 7.10 (clip-sealed boxed beef).
• Lactobacillus counts were significantly higher in clip-sealed boxed beef (6.93) compared to carcass front portions (4.39).
• Vacuum-packed beef exhibited substantially higher total (4.42) and fecal coliform (0.97) counts than carcass beef (0.97). Pseudomonas spp. dominated carcasses, while vacuum-packed beef had a mixed flora including Pseudomonas, Lactobacillus, and Aeromonas spp.

Conclusions:

• Beef processing and packaging methods significantly influence microbial contamination levels and profiles.
• Clip-sealed and vacuum-packed beef require careful handling and storage to mitigate microbial growth.
• Further research into controlling microbial load in packaged beef is warranted to ensure consumer safety.