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Food Protection Trends
Abstracts - September 2003
AnAssessment of the Safety of Cooling Large Cooked
Meats in the Catering Sector
Comparative Survival of Staphylococcus epidermidis,
Listeria monocytogenes, and Staphylococcus aureus on Hot-Smoked
Fish
AnAssessment
of the Safety of Cooling Large Cooked Meats in the Catering Sector
Nissreen Abu-Ghannam1* andPadraic
O’Brien2
1-*Department of Food Science and Environmental Health, Dublin Institute of
Technology,
Cathal Brugha Street, Dublin 1, Ireland
2-Western Health Board, Galway, Ireland
SUMMARY
Because of an increasing trend toward cooking large meat joints in advance of
service, the process of cook-chill has become an integral part of the catering
sector. However, there is concern that the cook-chill process is being adopted
by many conventional catering establishments that are significantly lacking
in the technology and management required for the process to be safe. Compliance
and practices associated with the safety of the cook-chill process were examined
in a range of 50 premises consisting of hotels, restaurants and take-aways.
Significant malpractice was seen in the cooling of large cooked meats. None
of the premises surveyed had rapid chillers, although 95% of them perform the
cook-chill practice. Consequently, the cooling time required to reach the recommended
10°C extended for up to 9 h, in contrast to the specified maximum of 150
min, resulting in conditions appropriate for Clostridia growth. Approximately
50% of respondents were unaware of the relevant guidelines and opted to use
guides that require less management control and financial investment. The cook-chill
process in the catering sector lacks compulsory specifications, which may have
misled caterers into concluding that their cooling practices are safe. Quantitative
assessment of the cooling process through temperature monitoring provides a
powerful tool for communicating to caterers the hazards associated with slow
cooling of large cooked meats.
Comparative
Survival of Staphylococcus epidermidis, Listeria monocytogenes,
and Staphylococcus aureus on Hot-Smoked Fish
Steven C. Ingham* and Maria M. Lau
Department of Food Science, University of Wisconsin-Madison,1605 Linden Drive,
Madison, WI 53706-1565, USA
SUMMARY
Inappropriate hand-to-food contact
may contaminate manually processed foods such as hot-smoked fish with Staphylococcus
aureus and Listeria monocytogenes. Staphylococci, including the important
skinborne species S. epidermidis, have been proposed as indicators of
hand-to-food contact. This study examined the survival of S. epidermidis
on various hot-smoked fish stored at 5 and 10°C and compared this survival to
that of L. monocytogenes and S. aureus. Populations of
S. epidermidis declined by 0.6 to 1.5 log units on the interior flesh
and skin surfaces of hot-smoked chubs during 10 days at 5 and 10°C. On the interior
flesh surface of hot-smoked lake trout, whitefish, and salmon, S. epidermidis
numbers declined by 0.2 to 1.2 log units during 21 days at 5°C. Decreases
of S. aureus (1.0 to 2.4 log units) were greater than those of S.
epidermidis, while L. monocytogenes grew by 3.2 to 3.7 log units
on hot-smoked chubs during 10 days at 10°C and 0.7 to 3.2 log units on hot-smoked
lake trout, whitefish, and salmon stored for 21 days at 5°C. The results show
that (1) L. monocytogenes can quickly grow to high numbers on hot-smoked
fish at 5 and 10°C and thus post-smoking contamination should be prevented,
and (2) if staphylococci numbers are to be used by quality control personnel
as an indicator of post-smoking manual contamination, then testing must be early
in the hot-smoked fish shelf life.
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