Microbial Persistence on Inoculated Beef Plates Sprayed with Hypochlorite Solutions | JoVE Visualize

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.