Microbial Persistence on Inoculated Beef Plates Sprayed with Hypochlorite Solutions

Area of Science:

• Food science
• Microbiology
• Food safety

Background:

• Bacterial contamination of beef carcasses is a significant food safety concern.
• Effective decontamination methods are crucial for reducing pathogen load on meat products.

Purpose of the Study:

• To evaluate the efficacy of hypochlorite solutions and spray pressure in reducing bacterial contamination on beef carcasses.
• To assess the impact of these treatments on bacterial persistence and beef quality parameters.

Main Methods:

• Beef carcass surfaces were inoculated with various bacteria (aerobic mesophilic, psychrotrophic, coliform, fecal coliform, Staphylococcus aureus).
• Treatments included spraying with city water or hypochlorite solutions (100-200 ppm) at different pressures (3.75-7.03 kg/cm²).
• Bacterial counts were analyzed at various time points post-treatment, and beef quality was assessed.

Main Results:

• Hypochlorite sprays significantly reduced coliforms, fecal coliforms, and S. aureus within 4 days.
• Aerobic mesophilic and psychrotrophic bacteria initially decreased but returned to inoculum levels within 8 days, increasing significantly at 4-6°C.
• Spray pressure was more effective than hypochlorite concentration for some bacteria, but hypochlorite treatments showed no significant advantage over city water for most bacterial types.
• A specific combination of intermediate pressure (5.25 kg/cm²) and 200 ppm hypochlorite yielded greater reductions in aerobic mesophiles and fecal coliforms at 2 days.
• No adverse effects on beef grade, muscle shear, or color were observed.

Conclusions:

• Hypochlorite sprays can reduce specific bacterial contaminants on beef carcasses, particularly coliforms and S. aureus.
• Spray pressure plays a significant role in bacterial reduction, sometimes more so than chemical concentration.
• Further optimization of hypochlorite application may be needed for broader bacterial control, as results were comparable to city water in many instances.
• Hypochlorite treatments do not negatively impact the quality attributes of beef carcasses.