David,
Pasteurization at 63C would eliminate the histamine producing vegetative
cells so histamine production during cooling is not a significant
hazard. What survives pasteurization are the spores of B cereus, C
perfringens and Non-proteolytic C botulinum. My research with Dr Juneja
show that cooling meat and poultry from 130F to 45F in 15 hours
controlled the outgrowth of the spores. The 6 hours is a government
number not based on research but rather personal opinion. They have no
scientific paper reference.
Your cooling procedure is safe.
Pete Snyder
David Byrom wrote:
>Dear List,
>Can anybody give me the scientifically proved safe length of cooling time
>for tuna for the production of cooked frozen tuna loins ?
>
>The tuna are defrosted from -18°C to -2 to 4°C and cooked to a BB
>temperature of 63°C. They are then showered with water and attain a backbone
>temperature of 30-35° C in approx. 4-5 hours (depending on fish size) after
>leaving the cooker. Ambient temp. is 25-30°C.The fish are pre-skinned and
>cleaned, vacuum packed and blast frozen. The BB temp. of the vacuum sealed
>pack achieves -18°C within 16 hours of being loaded into the blast freezer.
>
>I have heard widely conflicting ideas on the safe length of cooling time of
>the fish after cooking, from 6 hours to 24 hours by experienced seafood
>experts and industry people. I would be grateful if anybody could
>assist.with the correct answer to this issue.
>Thanks
>
>
>David J. Byrom
>Honiara
>Solomon Islands
>
>
>
>
>
>
-- O. Peter Snyder, Jr., Ph.D. Hospitality Institute of Technology and Management 670 Transfer Road, Suite 21A, St Paul, MN 55114 http://www.hi-tm.com Tel 651-646-7077 Fax 651-646-5984 One Worldwide qualified set of food safety guidelines.
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