The effect of temperature abuse on Clostridium perfringens in cooked turkey stored under air and vacuum

Abstract

The potential for growth of Clostridium perfringens in aerobic and anaerobic (vacuum) packaged cooked ground turkey was investigated. Samples of autoclaved ground turkey were inoculated with ∼3·0 log10 cfu g-1 of C. perfringens strain NCTC 8238 or NCTC 8239, packaged and stored at various temperatures. Vegetative growth and heat-resistant spores were enumerated by plating unheated and heated (75°C for 20 min) samples, respectively, on tryptose-sulfite-cycloserine agar. The type of atmosphere influenced the growth of C. perfringens at 15 and 28°C. Both strains grew to about 7 logs within 9 h anaerobically and by 24 h aerobically at 28°C. While aerobic growth was slow at 15°C, mean log10 cfu g-1 increased anaerobically by 4-4·5 logs by day 8 for both strains. Spores were not found at 4 and 15°C, but were detected as early as 24 h at 2°C under anaerobic conditions in both strains. C. perfringens population stabilized or slowly decreased at 4°C. Cyclic and static temperature abuse of refrigerated products for 5 h will not permit C. perfringens growth. However, temperature abuse of such products for relatively long periods may lead to high and dangerous numbers of organisms. Reheating such products to an internal temperature of 65°C before consumption would prevent food-poisoning since the vegetative cells were killed.