Inhibition of Clostridium perfringens Growth by Potassium Lactate during an Extended Cooling of Cooked Uncured Ground Turkey Breasts

摘要

The U.S. Department of Agriculture's Food Safety and Inspection Service compliance guideline known as Appendix B specifies chilling time and temperature limits for cured and uncured meat products to inhibit growth of spore-forming bacteria, particularly Clostridium perfringens. Sodium lactate and potassium lactate inhibit toxigenic growth of Clostridium botulinum, and inhibition of C. perfringens has been reported. In this study, a cocktail of spores of three C. perfringens strains (ATCC 13124, ATCC 12915, and ATCC 12916) were inoculated into 100-g samples of ground skinless, boneless turkey breast formulated to represent deli-style turkey breast. Three treatment groups were supplemented with 0 (control), 1, or 2% potassium lactate (pure basis), cooked to 71℃, and assayed for C. perfringens growth during 10 or 12 h of linear cooling to 4℃. In control samples, populations of C. perfringens increased 3.8 to 4.7 log CFU/g during the two chilling protocols. The 1% potassium lactate treatment supported only a 2.5- to 2.7-log increase, and the 2% potassium lactate treatment limited growth to a 0.56- to 0.70-log increase. When compared with the control, 2% potassium lactate retarded growth by 2.65 and 4.21 log CFU/g for the 10- and 12-h cooling protocols, respectively. These results confirm that the addition of 2% potassium lactate inhibits growth of C. perfringens and that potassium lactate can be used as an alternative to sodium nitrite for safe extended cooling of uncured meats.