ARS | Publication request: Growth Characteristics of Listeria monocytogenes and Native Microflora in Smoked Salmon Stored at Refrigerated and Abuse Temperatures

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: June 6, 2009
Publication Date: June 6, 2009
Citation: Hwang, C.,Sheen,S. 2009.Growth characteristics of Listeria Monocytogenes and Native Microflora in smoked salmon stored @ refrigerated and abuse temperatures [abstract].Institute of Food Technologists (IFT) Annual meeting. Anaheim,CA. p.1.

Technical Abstract: Smoked salmon contaminated with Listeria monocytogenes has been implicated in outbreaks of foodborne listeriosis. The objective of this study was to examine the growth characteristics of L. monocytogenes and native microflora in smoked salmon stored at refrigerated and abuse temperatures. Smoked salmon samples with a native microflora count of 2.9 log10 cfu/g were inoculated with a 6-strain mixture of L. monocytogenes to levels of 1.6 log10 and 2.8 log10 cfu/g, vacuum packed and stored at 4, 8, 12, and 16 degrees C. Growth characteristics (lag phase duration [LPD, h], growth rate [GR, log10 cfu/h], and maximum population density [MPD, log10 cfu/g]) of L. monocytogenes and native microflora were determined. At 4-16 degrees C, the LPD, GR, and MPD ranged from 254 to 35 h, 0.0109 to 0.0538 log10 cfu/h, and 4.9 to 6.9 log10 cfu/g for L. monocytogenes, respectively, and ranged from 257 to 29 h, 0.0102 to 0.0565 log10 cfu/h, and 8.5 to 8.8 log10 cfu/g for native microflora. The initial levels of L. monocytogenes didn’t significantly (p is greater than 0.05) affect the growth characteristics of L. monocytogenes or the native microflora in smoked salmon. Predictive models were developed to describe the LPD, GR, and MPD of L. monocytogenes and native microflora as a function of storage temperature. The growth relationship between L. monocytogenes and native microflora was modeled and showed that the LPD and GR of L. monocytogenes were similar to those of native microflora. These models can be used to estimate the growth characteristics of L. monocytogenes and native microflora in smoked salmon to assess the microbiological safety and quality of the product during storage at refrigerated and abuse temperatures.