Purpose: Compare outgrowth of Clostridium perfringens in turkey breast cured with various levels of nitrite from cultured celery juice powder and ascorbate from cherry powder during 15h cooling.
Methods: Ten treatments of deli-style turkey breast (76% moisture, pH 6.2, 1.2% NaCl) were prepared based on a two-factor full factorial design comprised of nitrite from celery powder (50, 75, and 100 ppm) and ascorbate from cherry powder (0, 250, and 500 ppm) and an uncured control. Treatments were inoculated with C. perfringens spores (three-strain mixture) to yield 3 log CFU/g. Individual 50-g portions were vacuum-packaged, cooked to 71.1°C and cooled from 54.4°C to 26.7°C in 5 hours and 26.7°C to 7.2°C in 10 additional hours. Triplicate samples were assayed for growth of C. perfringens at 0, 5, 10, and 15h by plating on tryptose-sulfite-cycloserine agar; experiments were replicated three times.
Results: The control, 50, 75, and 100 ppm nitrite and 50 ppm nitrite + 250 ppm ascorbate supported a 4.5 ± 0.4, 3.9 ± 0.2, 3.5 ± 0.3, 2.2 ± 0.6, and 1.5 ± 0.9 log increase, respectively, at 15h. In contrast, <1 log growth was observed through 15h in the remaining treatments.
Significance: This study confirmed that ascorbate enhances the antimicrobial impact of nitrite against C. perfringens at levels representative of alternatively cured meats, and demonstrated that products containing at least 75 ppm nitrite and 250 ppm cherry powder can be safely cooled over 15h according to Appendix B.