Growth and inactivation of Salmonella enterica and Listeria monocytogenes in broth and validation in ground pork meat during simulated home storage abusive temperature and home pan-frying

Abstract

Ground pork meat with natural microbiota and inoculated with low initial densities (1–10 or 10–100 CFU/g) of Salmonella enterica or Listeria monocytogenes was stored under abusive temperature at 10°C and thermally treated by a simulated home pan-frying procedure. The growth and inactivation characteristics were also evaluated in broth. In ground pork meat, the population of S. enterica increased by less than one log after 12-days of storage at 10°C, whereas L. monocytogenes increased by 2.3 to 2.8 log units. No unusual intrinsic heat resistance of the pathogens was noted when tested in broth at 60°C although shoulders were observed on the inactivation curves of L. monocytogenes. After growth of S. enterica and L. monocytogenes at 10°C for 5 days to levels of 1.95 log CFU/g and 3.10 log CFU/g, respectively, in ground pork meat, their inactivation in the burger subjected to a simulated home pan-frying was studied. After thermal treatment S. enterica was undetectable but L. monocytogenes was recovered in three out of six of the 25 g burger samples. Overall, the present study shows that data on growth and inactivation of broths are indicative but may underestimate as well as overestimate behavior of pathogens and thus need confirmation in food matrix conditions to assess food safety in reasonably foreseen abusive conditions of storage and usual home pan-frying of meat burgers in Belgium.

Mathematical modelling of growth ofListeria monocytogenesin raw chilled pork

“…Twenty‐six L. monocytogenes strains, previously isolated from chilled pork in our laboratory (Wang et al . ,b), were used in this study. Before experiments, all the strains were activated and purified on the PALCAM Agar (Luqiao Co., Beijing, China) at 37°C for 48 h, and cultivated in TSB‐YE Broth (Luqiao Co.).…”

“…It is ubiquitous in the environment, and can survive and grow in adverse conditions, such as at refrigeration temperatures and in foods with a high salt content or low pH (Wang et al . ,b). Invasive listeriosis exhibits a case fatality rate of about 30% (Dussurget ).…”

“…A few studies have been conducted to investigate the level of contamination in different meats and meat products (Stonsaovapak and Boonyaratanakornkit ; Yu and Jiang ; Wang et al . ,b). Wang et al .…”

“…Wang et al . (,b) showed that the prevalence of L. monocytogenes in chilled pork in Nanjing, China was 5·5%.…”

Interventions Targeting Deep Tissue Lymph Nodes May Not Effectively Reduce the Risk of Salmonellosis from Ground Pork Consumption: A Quantitative Microbial Risk Assessment

“…Not all pork products are of equal food safety risk. Fresh ground/minced meat has been identified as an important hazard for human consumption since it is particularly easier to be contaminated with pathogens than other types of meat (Lianou & Koutsoumanis, ; Self, Luna‐Gierke, Fothergill, Holt, & Vieira, ; Wang et al., ). The prevalence of Salmonella in retail fresh ground pork (FGP) is much higher at a level of 5.6% (Toro et al., ), whereas the prevalence of Salmonella ‐positive retail pork chops is relatively low, with an average value of 1.3% between 2002 and 2014 in the United States (NARMS, ).…”