Cooling meat products in foodservice: time, temperature, and growth of Clostridium perfringens ATCC 10388
Food safety remains a concern in commercial and institutional foodservice. Proper cooling of cooked food products can significantly reduce the chance of outbreaks of foodborne illness, yet cooling often is done incorrectly. Further, equipment for optimal cooling frequently is not available in foodservice operations, and time and temperatures during the cooling process seldom are checked. The purpose of this study was to determine the impact of various cooling methods used in foodservice on the microbiological safety of meat products. Specific objectives include comparing four cooling methods for cooked turkey roasts artificially inoculated with Clostridium perfringens spores and six cooling methods for chili. In addition, this study documented time and temperature continuously during the cooling process to determine if food cooling standards are being met. Typical cooling methods failed to meet time standards. Turkeys cooled in whole roast form under typical foodservice refrigeration showed an unacceptable and dangerous increase of up to 4.00log10CFU/roast in viable C. perfringens counts. No growth of C. perfringens occurred in blast-chilled whole turkey roasts and roasts divided into quarters and cooled under typical foodservice refrigeration, and an acceptable and beneficial reduction (-2.7 log10CFU/roast) in viable C. perfringens counts was observed when these methods were used. None of the cooling methods for turkey achieved established FDA time and temperature guidelines, indicating that these established cooling guidelines may be too stringent for foodservice operations. Chili, blast-chilled in two-inch and four-inch deep counter pans, met cooling guidelines, cooling from 1350F to 700F (570C to 210C) and from 700F to 410F (210C to 50C) in two and four hours, respectively; however, chili cooled using the same-sized pans under typical foodservice refrigeration did not. Chili cooled in 3-gallon increments under typical foodservice refrigeration (390F[3.90C]) took approximately 24 hours to cool from 1350F to 410F (570C to 50C. With the use of a chill stick, the same 3-gallon container of chili cooled in approximately six hours. Further research is needed using typical cooling methods with different food products and foodservice operators need to implement appropriate cooling methods to ensure proper cooling of potentially hazardous foods.