Viability of Listeria monocytogenes on Uncured Turkey Breast Commerically-prepared with and without Buffered Vinegar during Extended Storage at 4°C and 10°C

Introduction: The antimicrobial effectiveness of lactates for controlling Listeria monocytogenes (Lm) in ready-to-eat (RTE) meat products is well documented. However, levels of these antilisterial ingredients commonly used by the meat industry are less effective at controlling Lm on uncured RTE meats than on cured RTE products.

Purpose: Determine viability of Lm on uncured turkey breast containing buffered vinegar (BV) and surface treated with a stabilized solution of sodium chlorite in vinegar (VSC).

Methods: Commercially-produced, uncured, deli-style turkey breast was formulated with or without BV (2.0, 2.5, or 3.0%), sliced (ca. 1.25 cm thick), and subsequently surface inoculated (ca. 4.3 log CFU/slice) with a five-strain cocktail of Lm. Next, 1 ml of a 2 or 10% solution of VSC was added to each package before vacuum sealing and then storing at 4°C or 10°C.

Results: Without antimicrobials, Lm increased by ca. 6.2 log CFU/slice after 90 and 48 days of storage at 4°C or 10°C, respectively. At 4°C, Lm increased by ca. 0.4 to 1.9 log CFU/slice on turkey breast formulated with 2.0 or 2.5% of BV and treated or not with 2% VSC, whereas when treated with 10% VSC, Lm 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/slice. At 10°C, Lm increased by ca. 1.5 to 5.6 log CFU/slice after 48 days when formulated with 2.0 to 3.0% of BV and treated or not with 2% VSC. When formulated with 2.0% BV and treated with 10% VSC Lm increased by ca. 3.3 log CFU/slice, whereas when formulated with 2.5 to 3.0% BV and treated with 10% VSC Lm decreased by ca. 0.3 log CFU/slice.

Significance: Inclusion of BV, alone or in combination with VSC, in uncured turkey breast suppressed outgrowth of Lm during shelf life.