Investigation of the Impact of Cook-In Oxygen Permeable Bags on the Survival of Clostridium perfringens in Sous Vide Cooked Meat

Abstract

Sous vide cookery utilizes low-temperature heating in sealed vacuum packaging within a water bath to provide consistent and even cooking. While regarded as a generally safe method, there are concerns regarding its effectiveness against anaerobic pathogens. Clostridium perfringens, an anaerobic spore-forming bacterium commonly associated with cooked meat, may become a risk if vacuum-sealed products are improperly handled after cooking, such as being held at temperatures that allow C. perfringens to proliferate. This study evaluated the survival of C. perfringens in inoculated beef cooked sous vide in vacuum‑packaged (VP) or oxygen‑permeable (OPP) bags. Beef steaks were inoculated with a cocktail C. perfringens culture, sealed, and cooked at 57.5 °C and 52.5 °C for various times following typical sous vide parameters. After heating, samples were cooled and remaining vegetative C. perfringens were enumerated using standard anaerobic plating methods to quantify bacterial reductions. Both packaging types achieved substantial reductions during cooking. At 52.5 °C, final cooking time reductions were 4.00 (3.65-4.69) log₁₀ CFU/cm2 for VP and 4.90 (4.39-6.34) log₁₀ CFU/cm2 for OPP; at 57.5 °C they were 5.76 (4.87-7.88) log₁₀ CFU/cm2 for VP and 6.06 (5.57-6.74) log₁₀ CFU/cm2 for OPP. Although reductions were greater in oxygen-permeable packaging, the wide confidence intervals indicate variability, suggesting that cooking temperature may have played a greater role in C. perfringens inactivation than packaging type. Additional research is needed to understand bacterial behavior after cooking, particularly spore germination during cooling and refrigeration and with thicker meat samples, so initial starting temperature is more consistent.