Viability of Listeria monocytogenes on uncured turkey breast commercially prepared with and without buffered vinegar during extended storage at 4 and 10°C.

We determined the viability of Listeria monocytogenes on uncured turkey breast containing buffered vinegar (BV) and surface treated with a stabilized solution of sodium chlorite in vinegar (VSC). Commercially produced, uncured, deli-style turkey breast was formulated with BV (0.0, 2.0, 2.5, or 3.0%), sliced (ca. 100 g and ca. 1.25 cm thick), and subsequently surface inoculated (ca. 4.3 log CFU per slice) in each of two trials with a five-strain cocktail of L. monocytogenes. Next, 1 ml per side of a 2 or 10% solution of VSC was added to each package before vacuum sealing and storing at 4 or 10°C. Without antimicrobials, L. monocytogenes numbers increased by ca. 6.2 log CFU per slice after 90 and 48 days of storage at 4 or 10°C, respectively. At 4°C, L. monocytogenes numbers increased by ca. 0.4 to 1.9 log CFU per slice on turkey breast formulated with 2.0 or 2.5% BV and treated or not with 2% VSC, whereas when treated with 10% VSC, L. monocytogenes levels remained relatively unchanged over 90 days. However, when turkey breast was formulated with 3.0% BV and treated or not with VSC, pathogen numbers decreased by ca. 0.7 to 1.3 log CFU per slice. At 10°C, L. monocytogenes numbers increased by ca. 1.5 to 5.6 log CFU per slice after 48 days when formulated with 2.0 to 3.0% BV and treated or not with 2% VSC. When formulated with 2.0% BV and treated with 10% VSC, L. monocytogenes numbers increased by ca. 3.3 log CFU per slice, whereas when formulated with 2.5 or 3.0% BV and treated with 10% VSC, L. monocytogenes decreased by ca. 0.3 log CFU per slice. Inclusion of BV as an ingredient in uncured turkey breast, alone or in combination with VSC added to the package, appreciably suppressed outgrowth of L. monocytogenes during an extended refrigerated shelf life.