Survival and growth of Listeria monocytogenes and Staphylococcus aureus on conventional and low-sodium bacon-A short communication

Abstract

This study was focused on determining survival and growth characteristics of Listeria monocytogenes and Staphylococcus aureus on conventional (16.7 mg of sodium/g) and low-sodium (10.7 mg of sodium/g) bacon. The two types of bacon were inoculated with the either L. monocytogenes or S. aureus stored at 4, 12, or 25 degrees C for up to 7 days. Populations of L. monocytogenes and S. aureus did not change significantly on bacon stored at 4 and 12 degrees C, regardless of sodium content. L. monocytogenes remained at 1.0-1.5 log cfu/g of conventional bacon stored at 25 degrees C for 7 days but increased to 3.5 log cfu/g on low-sodium bacon stored for 4 days. Within 1 and 3 days at 25 degrees C, S. aureus increased, respectively, to 4.5 log cfu/g and 7.3 log cfu/g of low-sodium bacon. Within 7 days at 25 degrees C, populations increased to 8.1 log cfu/g of low-sodium bacon and 3.7 log cfu/g of conventional bacon. This study shows that L. monocytogenes can grow on low-sodium bacon stored at 25 degrees C. S. aureus can grow on bacon stored at 25 degrees C, regardless of sodium content, but the presence of 16.7 mg of sodium/g, compared to 10.7 mg/g, retards the rate of growth. Practical applications At 25 degrees C, L. monocytogenes and S. aureus grew more rapidly on low-sodium bacon than on conventional bacon. Low-sodium bacons increase concern for microbiological safety. Storage of conventional and low-sodium bacon at 25 degrees C enables growth of both pathogens. Appropriate temperature for storage is more critical to enhance the microbiological safety of bacons rather than amount of sodium added.