Inhibition of Listeria monocytogenes and Escherichia coli O157:H7 on frankfurters using scallop-shell powder
Posted: April 27th, 2010 - 12:45pm
Source: Journal of Food Safety
This study investigated the effect of scallop-shell powder (SSP) on the growth of Listeria monocytogenes or Escherichia coli O157:H7 on frankfurters. The frankfurters inoculated with L. monocytogenes or E. coli O157:H7 were immersed in a 0, 0.05 or 0.1% (w/v) SSP slurry for 10 or 30 min. Populations of L. monocytogenes, E. coli O157:H7, mesophilic aerobic bacteria (MAB), lactic acid bacteria and yeast/mold were determined at 0 or 7th days of storage at 4C along the level of L-ascorbic acid, moisture content, pH and sensory properties. Numbers of L. monocytogenes and E. coli O157:H7 decreased 3.6 and 5.0 logs by 0.10% SSP for 10 min, respectively, with both pathogens inhibited during 7 days. Populations of MAB and yeast decreased about 1.5 or 1 logs, respectively, after a 10-min exposure to SSP. L-ascorbic acid value, sensory attributes and pH did not change with SSP treatment.
The occurrence of Listeria monocytogenes and Escherichia coli O157:H7 on the surface of frankfurters have been a problem (USDA-FSIS 2009). Accordingly, the present study was conducted to assess the ability of scallop-shell powder (SSP) to reduce the number of L. monocytogenes and E. coli O157:H7 and also inhibit their growth on frankfurters during their storage. The result of the study showed that immersing frankfurters in SSP slurries for 10 min before packaging can reduce the number of L. monocytogenes, E. coli O157:H7 and natural flora of frankfurters without changing any sensory or chemical properties; therefore, this method can be an alternative to produce safer frankfurters with longer shelf life.