Purpose: To determine the antilisterial effect of commercial ingredients containing various combinations of propionate, diacetate, acetate, and lactate in cured turkey stored at 4 and 7°C for up to 12 weeks.
Methods: Eight cured deli-style turkey breast treatments (75 - 76% moisture, pH ~6.3, ~1.95% NaCl, 156 mg/kg NaNO2, 547 mg/kg sodium erythorbate) were formulated with 0.2, 0.4 or 0.65% Provian®D (sodium acetate, lactate and diacetate; proprietary blend) or 0.25, 0.5, or 0.75% Provian®K (potassium acetate and diacetate; proprietary blend). Control treatments included turkey formulated with no antimicrobials or with 2.5% potassium lactate-sodium diacetate (56-4%) blend. Sliced cooked products were surface inoculated with 3 log CFU/g of L. monocytogenes (5-strain mix), vacuum packaged (100 g/package), and stored at 4°C and 7°C. Triplicate samples per treatment were assayed at 0, 2, 4, 6, 8, 10 weeks for both storage temperatures and an additional 12th week at 4°C by enumerating on Modified Oxford Agar.
Results: Treatments containing no antimicrobials or with 0.2% Provian®D supported > 1-log increase of L. monocytogenes by 6 and 10 weeks at 4°C, respectively; the remaining six treatments inhibited growth (< 0.5-log increase) through 12 weeks. In contrast, only treatments containing ≥ 0.25% Provian®K and ≥ 0.4% Provian®D inhibited growth (< 0.5-log increase in L. monocytogenes) for the 10 weeks storage at 7°C, whereas the two control treatments and the 0.2% Provian®D treatment supported > 1-log increase of L. monocytogenes within 4 to 10 weeks. Both control treatments supported growth at times within ranges predicted by a commercially-available model for L. monocytogenes inhibition.
Significance: Results from this study validate the efficacy of additional commercial antimicrobials to inhibit growth of L. monocytogenes on Ready-to-Eat meat and poultry products.