The effect of lauric arginate on the thermal inactivation of starved Listeria monocytogenes in sous-vide cooked ground beef

Abstract

The aim of this study was to examine the efficacy of lauric arginate (LAE, 1000 ppm - 3000 ppm) as an assisting tool to reduce starved Listeria monocytogenes population in ground beef following sous-vide processing at different temperatures (55-62.5 °C). Ground beef mixed with LAE was vacuum sealed and a laboratory water bath was used for sous-vide cooking. Loglinear and Weibull models were fit to the survival microbial population and the D and Z-values were determined at 55-62.5 °C. Calculated D-values ranged from 33.62 to 3.22 min at temperature 55-62.5 °C. LAE at higher concentration is an effective antimicrobial to increase the inactivation of the pathogen in sous-vide cooking. With the addition of LAE, D-values at 55 and 62.5 °C determined by the Loglinear model decreased from 31.86 to 2.28 min (LAE 1000 ppm) and 16.71 to 0.56 min (LAE 3000 ppm), respectively; whereas the D-values at 55 to 62.5 °C determined by the Weibull model were 44.26 and 2.09 min (LAE 1000 ppm) and 22.71 and 1.60 min (LAE 3000 ppm), respectively. This study shows that sous-vide processing of ground beef supplemented with higher concentration of LAE effectively inactivates L. monocytogenes and thus, helps increase the microbiological safety and product quality.

Keywords: Beef; L. monocytogenes; Lauric arginate; Sous-vide; Thermal inactivation.