Microbial Changes of Precooked Beef Slices as Affected by Packaging Procedure

Area of Science:

• Food Science
• Microbiology
• Meat Science

Background:

• Microbial spoilage limits the shelf-life of precooked beef.
• Effective packaging strategies are crucial for maintaining meat quality during retail storage.

Purpose of the Study:

• To evaluate the impact of vacuum packaging versus modified atmosphere packaging (MAP) on microbial growth in precooked beef slices.
• To determine the influence of different storage temperatures on microbial proliferation.

Main Methods:

• Precooked beef slices were packaged under vacuum or a gas mixture (15% CO2/40% O2/45% N2).
• Slices were stored at 2°C, 6°C, or 10°C for up to 21 days.
• Microbial counts (psychrotrophs, mesophiles, thermophiles, molds) were enumerated at regular intervals.

Main Results:

• Psychrotrophic bacteria increased in vacuum-packaged beef at 2°C by day 21, but not in MAP.
• At higher temperatures (6°C and 10°C), psychrotrophs increased in MAP but not in vacuum-packaged beef.
• Mesophiles and molds showed no significant increase under most conditions, especially at 2°C.

Conclusions:

• Modified atmosphere packaging effectively inhibits psychrotrophic growth in precooked beef at 2°C.
• Packaging treatment and storage temperature significantly influence microbial stability in retail beef products.