Purpose: To determine the effectiveness of a 5% lactic acid dip and a 5% potassium lactate dip to reduce Salmonella on naturally contaminated beef purchased in wet markets in Mexico.
Methods: Non-federally inspected beef whole muscle steaks (approximately 100 grams each) were purchased from city markets, street vendors and butcher shops across 4 cities in Mexico. In the first experiment, samples (n=362, 2 replications) were dipped in 5% lactic acid solution. The second study, samples (n=722, 4 replications) were dipped in a 5% potassium lactate solution. In both studies, duplicate non-treated steaks serve as controls. For each sample, the presence of Salmonella was determined with the BAX® system, and if confirmed, MPN enumeration was performed and colonies confirmed using a latex test. All data was analyzed with Statistical Analysis System (SAS 9.3) software.
Results: Lactic acid study controls, resulted in 44.48% positive for Salmonella as compared to 34.25% positve after the lactic acid dip. Lactic acid treatment revealed an average Salmonella level of 2.21 MPN/g log /50cm², significantly less than the controls, 2.80 log /50cm² (P < .0001).
Potassium lactate treatment resulted in 31.72% positive for Salmonella compared to controls (34.49% positive). There was a statistically significant difference in the controls versus treated samples counts which was 3.15 and 2.81 MPN/g log /50cm², respectively (P < 0.0073).
Significance: Results indicated that in Mexico there is an unacceptable amount of beef contaminated with Salmonella, but the lactic acid and potassium lactate dips can reduce its levels, providing safer beef products to the citizens of Mexico.