The immediate bactericidal effect of lactic acid on meat-borne pathogens

Area of Science:

• Food Microbiology
• Food Safety
• Bacteriology

Background:

• Meat-borne pathogens pose significant food safety risks.
• Lactic acid decontamination (LAD) is a potential method for reducing microbial contamination on meat surfaces.

Purpose of the Study:

• To investigate the kinetics of LAD's bactericidal effect on key meat-borne pathogens.
• To determine the influence of pH and temperature on LAD efficacy.

Main Methods:

• An in-vitro model was used to study LAD's effect on Salmonella spp., Campylobacter jejuni, and Listeria monocytogenes.
• Experiments varied lactic acid concentration (1-2%), pH (2.6-4.0), temperature (21-37°C), and treatment time (30-90s).
• Mesophilic Enterobacteriaceae served as indicator organisms.

Main Results:

• Bactericidal effect was highest in the lactic acid film and decreased with increasing pH.
• At 2% lactic acid and 21°C, Salmonella spp. reduction decreased from 2 log10 cfu at pH 2.6 to insignificant levels at pH 4.0.
• Higher temperatures (37°C) countered the reduced efficacy at higher pH for Salmonella spp. and Campylobacter jejuni.
• 1% lactic acid at pH 3.0 and 21°C was effective against Campylobacter jejuni.
• LAD at 2% and 37°C for 30-90s eliminated Salmonella but not Listeria monocytogenes.

Conclusions:

• 2% Lactic acid decontamination at 37°C for 30-90s is effective for Salmonella elimination on meat.
• Lactic acid decontamination efficacy is significantly influenced by pH and temperature.
• Mesophilic Enterobacteriaceae can reliably indicate LAD effectiveness against Salmonella and Campylobacter.