Controlled vapor oven cooking and holding procedures used for the reduction of Salmonella and prevention of growth of Clostridium perfringens in boneless beef rib roasts

The FDA 2005 Food Code whole meat roast cooking guidelines were used to evaluate controlled vapor oven cooking and holding of boneless beef rib roasts weighing 13.0 to 14.0 lb (5.89 to 6.35 kg) at 130F (54.4C). The efficacy of the controlled vapor oven cooking, holding, cooling, cold holding, and reheating procedures was evaluated on the basis of the ability of the procedures to produce a 5-log reduction of a Salmonella inoculum on the surface and in the center of the beef roasts and to control the growth of Clostridium perfringens in the center of the roasts. This study showed that 6-hour cooking of beef roasts at 130F (54.4C) Wet Bulb Temperature, with oven relative humidity of 30 to 90%, met regulatory requirements for the destruction of Salmonella, even though the roast temperatures reached only 120 to 128F (48.9 to 53.3C). There was a slight increase in C. perfringens counts during cooking, indicating spore germination and vegetative cell growth. However, when the roasts were held at 130F (54.4C) during post cook-hold, C. perfringens was reduced to an undetectable level. During post-cook-chill-hold and retherm (reheating), a small population of C. perfringens that had been reduced to undetectable levels (< 10 CFU/g) was detected. This observation indicates that a safer way to hold cooked roast beef is to hold the roasts at a controlled vapor oven temperature of 130F (54.4C) until consumed rather than to cool and reheat leftovers.