Inhibition of Germination and Outgrowth of Clostridium perfringens Spores by Lactic Acid Salts during Cooling of Injected Turkey†

Abstract

Inhibition of Clostridium perfringens spore germination and outgrowth by lactic acid salts (calcium, potassium, and sodium) during exponential cooling of injected turkey product was evaluated. Injected turkey samples containing calcium lactate, potassium lactate, or sodium lactate (1.0, 2.0, 3.0, or 4.8% [w/w]), along with a control (product without lactate), were inoculated with a three-strain cocktail of C. perfringens spores to achieve a final spore population of 2.5 to 3.0 log CFU/g. The inoculated product was heat treated and exponentially cooled from 54.5 to 7.2°C within 21, 18, 15, 12, 9, or 6.5 h. Cooling of injected turkey (containing no antimicrobials) resulted in C. perfringens germination and an outgrowth of 0.5, 2.4, 3.4, 5.1, 5.8, and 5.8 log CFU/g when exponentially cooled from 54.4 to 7.2°C in 6.5, 12, 15, 18, and 21 h, respectively. The incorporation of antimicrobials (lactates), regardless of the type (Ca, Na, or K salts), inhibited the germination and outgrowth of C. perfringens spores at all the concentrations evaluated (1.0, 2.0, 3.0, and 4.8%) compared to the injected turkey without acetate (control). Increasing the concentrations of the antimicrobials resulted in a greater inhibition of the spore germination and outgrowth in the products. In general, calcium lactate was more effective in inhibiting the germination and outgrowth of C. perfringens spores at ≥1.0% concentration than were sodium and potassium lactates. Incorporation of these antimicrobials in cooked, ready-to-eat turkey products can provide additional protection in controlling the germination and outgrowth of C. perfringens spores during cooling (stabilization).