P1-148 An Investigation into the Temperature Variation during Hot Holding of Cooked Mussels in Domestic Coolers

Monday, July 29, 2013
Exhibit Hall (Charlotte Convention Center)
Richard Meldrum, Ryerson University, Toronto, Canada
Peter Millar, Ryerson University, Toronto, Canada
Introduction: It is relatively common during outdoor events in the province of Prince Edward Island, Canada for commercial vendors to store cooked mussels in domestic coolers to keep the product hot before sale. Provincial legislation requires that all hot products should be maintained at a minimum temperature of 60°C.

Purpose: A study was conducted to ascertain how long hot, cooked mussels could be stored for in domestic coolers before the temperature decreased to below 60°C. 

Methods: Mussels were cooked using guidance published by Health Canada, then placed into domestic coolers and the temperature measured at five different locations every ten minutes for up to four hours.  Three experiments were conducted; in the first the cooler was not opened, in the second the cooler was opened for one minute every ten minutes and in the third the cooler was opened for one minute every ten minutes and some mussels removed.  Each experiment was conducted in triplicate.

Results: It was found that when the cooler was left unopened, the mean temperature dropped to < 60°C in 56 minutes.  For coolers opened every 10 minutes the mean temperature decreased to < 60°C in 38 minutes.  For coolers opened every ten minutes and mussels removed, the mean temperature decreased to < 60°C in 52 minutes. For all three experiments, the temperature dropped into the “danger zone” for microbial growth within the four hour experimental period.

Significance: It was clear from the results that this method of storing mussels for commercial sale is not appropriate.  It was concluded that mussels should not be stored under these conditions for > 30 minutes and temperature should be regularly monitored to ensure it stays within legislated limits.