Impact of Cooking, Cooling, and Subsequent Refrigeration on the Growth or Survival of Clostridium perfringens in Cooked Meat and Poultry Products

Abstract

In January 1999, the Food Safety and Inspection Service (FSIS) finalized performance standards for the cooking and chilling of meat and poultry products in federally inspected establishments. More restrictive chilling (stabilization) requirements were adopted despite the lack of strong evidence of a public health risk posed by industry practices employing the original May 1988 guidelines (U.S. Department of Agriculture FSIS Directive 7110.3). Baseline data led the FSIS to estimate a "worst case" of 10(4) Clostridium perfringens cells per g in raw meat products. The rationale for the FSIS performance standards was based on this estimate and the assumption that the numbers detected in the baseline study were spores that could survive cooking. The assumptions underlying the regulation stimulated work in our laboratory to help address why there have been so few documented outbreaks of C. perfringens illness associated with the consumption of commercially processed cooked meat and poultry products. Our research took into account the numbers of C. perfringens spores in both raw and cooked products. One hundred ninety-seven raw comminuted meat samples were cooked to 73.9 degrees C and analyzed for C. perfringens levels. All but two samples had undetectable levels (<3 spores per g). Two ground pork samples contained 3.3 and 66 spores per g. Research was also conducted to determine the effect of chilling on the outgrowth of C. perfringens spores in cured and uncured turkey. Raw meat blends inoculated with C. perfringens spores, cooked to 73.9 degrees C, and chilled according to current guidelines or under abuse conditions yielded increases of 2.25 and 2.44 log10 CFU/g for uncured turkey chilled for 6 h and an increase of 3.07 log10 CFU/g for cured turkey chilled for 24 h. No growth occurred in cured turkey during a 6-h cooling period. Furthermore, the fate of C. perfringens in cooked cured and uncured turkey held at refrigeration temperatures was investigated. C. perfringens levels decreased by 2.52, 2.54, and 2.75 log10 CFU/g in cured turkey held at 0.6, 4.4, and 10 degrees C, respectively, for 7 days. Finally, 48 production lots of ready-to-eat meat products that had deviated from FSIS guidelines were analyzed for C. perfringens levels. To date, 456 samples have been tested, and all but 25 (ranging from 100 to 710 CFU/g) of the samples contained C. perfringens at levels of <100 CFU/g. These results further support historical food safety data that suggest a very low public health risk associated with C. perfringens in commercially processed ready-to-eat meat and poultry products.

Evaluation of a Clostridium perfringens Predictive Model, Developed under Isothermal Conditions in Broth, To Predict Growth in Ground Beef during Cooling

“…Our results also show good agreement with those of Kalinowski et al (14), who demonstrated a net growth of more than 2 log 10 CFU/g was observed during cooling uncured turkey samples from 48.9 to 12.8°C over 6 h, which is a rate approximately equivalent to the 12-h cooling process shown in Table 1. Again, the Juneja 1999 model underpredicts the growth observed by Kalinowski et al…”

Clostridium perfringens in London, July 2009: two weddings and an outbreak

“…Furthermore, the vans used for food transport had no refrigeration and these events took place in July. The evidence of insufficient hygiene, cooling and reheating at the catering company during transport and at both venues (according to environmental health department inspections) are in keeping with a toxin-related gastroenteritis outbreak, including C. perfringens enterotoxin [4,9,10]. As the distance from the caterer to venue B was substantially longer than to venue A, the lack of adequate temperature control during transport may have led to a higher infective dose in venue B, which could explain the shorter incubation time and higher proportion of cases with vomiting.…”

Survival and Germination of Clostridium perfringens Spores during Heating and Cooling of Ground Pork

“…Several challenge studies have been conducted under laboratory conditions to investigate growth of C. perfringens during cooling of cooked meat products (20,31). However, the cooking conditions in these studies were not representative of the cooking processes used in commercial establishments.…”