Inhibition of Clostridium perfringens in High-Moisture, Uncured Turkey Products by Vinegar-Based Clean-Label Ingredients During Extended Cooling

Abstract

The United States Department of Agriculture Food Safety and Inspection Service (USDA-FSIS) Appendix B guidelines identify cooling options to prevent growth of Clostridium perfringens in uncured meat and poultry products where Phase 1 cooling (between 49 and 27°C) is limited to 1 h and continued chilling to 4°C. This study screened several commercially available vinegar-based clean-label ingredients to inhibit C. perfringens in a model poultry product during extension of Phase 1 cooling. Eight uncured turkey products (75% moisture, 1.5% salt, pH 6.6 and 6.2) were formulated with no antimicrobial (control) or 1% dry vinegar (DV), dry vinegar-cultured sugar (DV-CS), or dry vinegar-fruit-spice-extract (DV-FSE). The batter was inoculated with 2.5-log CFU/g C. perfringens spores (3-strain mixture), vacuum- packaged (25 g/pouch), cooked to 70°C, and cooled according to the following schedule: Phase 1 (48.9 – 26.7°C) in 2, 3, 4, or 5 h; Phase 2 (26.7 – 12.8°C) in 5 h; and Phase 3 (12.8 – 4.4°C) in 5 h (total cooling 12, 13, 14, or 15 h). Triplicate samples were enumerated after cooking and at the end of each phase; each experiment was replicated twice. As expected, C. perfringens grew rapidly in control samples (> 1.5-log and > 6-log for the 2- and 5-h extended Phase 1 cooling, respectively). In contrast, treatments containing 1% DV or DV-FSE inhibited 1-log growth at pH 6.6 and 6.2 when Phase 1 cooling was extended to 2 and 3 h, respectively. Turkey containing 1% DV-CS at pH 6.6 and 6.2 inhibited C. perfringens to ≤ 1-log when Phase 1 was extended 4 and 5 h, respectively. This study confirms that DV-based clean-label antimicrobials can be used by manufacturers to extend Phase 1 cooling of uncured meat and poultry products beyond the recommendations in the 2021 USDA-FSIS Appendix B Option 2 Stabilization Guidelines. Further research is needed to compare the efficacy of similar ingredients among various suppliers.