|LI, CHANGCHENG - Fujian Agricultural & Forestry University|
|Hwang, Cheng-An - Andy|
|CHEN, JINQUAN - Fujian Agricultural & Forestry University|
Submitted to: Food Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/7/2015
Publication Date: 6/12/2015
Publication URL: http://handle.nal.usda.gov/10113/61025
Citation: Li, C., Huang, L., Hwang, C., Chen, J. 2015. Growth of Listeria monocytogenes in Salmon Roe - a kinetic analysis. Food Control. DOI:10.1016/j.foodcont.2015.06.016.
Interpretive Summary: Listeria monocytogenes is a major foodborne pathogen that can be found in seafood products, such as salmon roe. This study was conducted to develop mathematical models to predict the growth of L. monocytogenes in salted and unsalted salmon roe. Results show that adding 3% salt to salmon roe increased the lag phase of L. monocytogenes by 40%, while the growth rates were not affected. Mathematical models were developed to describe the growth of L. monocytogenes in salmon roe under different storage temperature conditions. The models developed in this study can be used by the seafood industry and regulatory agencies to more accurately estimate the growth of L. monocytogenes in and conduct risk assessments of the safety of salmon roe products.
Technical Abstract: The objective of this study was to investigate the growth kinetics of Listeria monocytogenes in unsalted and salted (3%) salmon roe. Growth curves, developed using inoculated samples incubated at constant temperatures between 5 and 30 degrees C, were analyzed by curve-fitting to the Huang and Baranyi models using the USDA IPMP 2013. The experimental results showed that L. monocytogenes in salted samples exhibited approximately 40% longer lag times than the cells in unsalted samples under the same temperature condition, while the rates of bacterial growth were not affected by the addition of salt. The Ratkowsky square-root (RSR) model, Huang square-root (HSR) model, and an Arrhenius-type model were all shown suitable for evaluating the effect of temperature on specific growth rates. The estimated nominal minimum growth temperature in the RSR model was -0.5 degrees C, whereas the minimum growth temperature in HSR model was 2.57 degrees C. The HSR models may be more suitable for describing the temperature effect in salted salmon roe. The lag times of L. monocytogenes were found to change log-linearly with the specific growth rates. The mean h0 in the Baranyi model was 0.742 in unsalted samples and 1.193 in salted samples, and did not appear to change with temperature in a systematic manner. In summary, kinetic models were developed for examining the effect of temperature on growth of L. monocytogenes in unsalted and salted salmon roe samples. The results may be used by the food industry and regulatory agencies to estimate the growth of L. monocytogenes in salmon roe, and to conduct risk assessments of this microorganism.