Fate of Listeria monocytogenes in processed meat products during refrigerated storage

Abstract

The fate of Listeria monocytogenes during refrigerated storage was determined on several processed meat products, including ham, bologna, wieners, sliced chicken, sliced turkey, fermented semidried sausage, bratwurst, and cooked roast beef. The meats were surface inoculated with a five-strain mixture of <200 or ca. 105 L. monocytogenes cells per package, vacuum packaged, and stored at 4.4°C. Survival or growth of listeriae was determined for up to 12 weeks of storage or until the product was spoiled. The organism survived but did not grow on summer sausage, grew only slightly on cooked roast beef, grew well on some wiener products but not on others, grew well (103 to 104 CFU/g increase within 6 weeks) on ham, bologna, and bratwurst, and grew exceptionally well (103 to 105 CFU/g increase within 4 weeks) on sliced chicken and turkey. The rate of growth depended largely upon the type of product and the pH of the product. Growth was most prolific on processed poultry products. The organism generally grew well on meats near or above pH 6 and poorly or not at all on products near or below pH 5. These results indicate the importance of preventing postprocessing contamination of L. monocytogenes in a variety of ready-to-eat meat products.

Effects of autochthonous Lactobacillus plantarum strains on Listeria monocytogenes in sucuk during ripening

“…In our study, pH value was 5.44 at the first day in control group (Figure 1), so that L. monocytogenes showed a significant growth (Figure 3). Similar findings were determined in sucuk (Kaya & Gökalp, 2004a, 2004b and beaker sausage (Glass & Doyle, 1989), produced without starter cultures. In contrast, at the same day, L. monocytogenes did not show growth in sucuk groups with L. plantarum strains because of that their pH values were below 5.0 (Figure 1).…”

Scientific Opinion on the public health risks related to the maintenance of the cold chain during storage and transport of meat. Part 2 (minced meat from all species)

“…L. monocytogenes grow optimally at 30 °C to 37 °C (James and James, 2014) but are also capable of growing at -1 °C, although inoculation studies in ground beef suggest survival but no growth at 4 °C (Johnson et al, 1988). Glass and Doyle (1989) found that growth of L. monocytogenes on meat was highly dependent on product type and pH. The organism tended to grow well on meat products with a pH value near or above 6.0, whereas it grew poorly or not at all on meats near or below pH 5.0.…”

Survival of Listeria monocytogenes and Salmonella typhimurium and Quality Attributes of Cooked Pork Chops and Cured Ham after Irradiation

“…Junttila et al (1989) determined that salt content of Finnish fermented sausages at 3-3.5% had little effect on L. monocytogenes. From a study on processed meat products, Glass and Doyle (1989) suggested that L. monocytogenes generally grew well on meats near or above pH 6 and poorly or not at all on products near or below pH 5. The pH of the chops (Table 1) was 5.7-5.9 at day 0.…”