Growth of Listeria monocytogenes Scott A during Kimchi Fermentation and in the Presence of Kimchi Ingredients

Abstract

The fate of Listeria monocytogenes was determined during kimchi fermentation and in the presence of kimchi ingredients. The lag phase was increased in tryptic soy broth at 35°C in the presence of 3% garlic, ginger, and NaCl, but not in the presence of 5% red pepper. Low levels (104 CFU/ml) of kimchi microflora did not inhibit the growth of Listeria in brain heart infusion (BHI) broth at 35°C. The growth of L. monocytogenes was inhibited in BHI broth containing a mixture of kimchi ingredients and 3% (wt/vol)NaC1 at 21°C. During kimchi fermentation at 21and 35°C, the numbers of viable cells of L. monocytogenes increased for the first 2 days of fermentation, but decreased during the next 10days. The decrease at 35°C was more rapid. L. monocytogenes was largely inactivated by kimchi ingredients and low pH, but viable cells still remained after 10 days of fermentation. These results show that kimchi is a safe product with respect to low levels of Listeria contamination which can be achieved by using ingredients of good microbiological quality.