22

I've been part of many discussions about why it's unsafe to store cooked food at room temperature past two hours. An old question (How long can cooked food be safely stored at room/warm temperature?) links to USDA with common guidance that it is not safe to keep cooked food at room temperature for beyond 2 hours.

However, government agency policies are fairly opaque. Here are specific questions:

If meat is cooked in a slow cooker, what happens to it once it cools off and is left at room temperature for over two hours? If it was safe to eat when it was hot, what happens past two hours? How to bacteria get in (were they already in) and when do toxins form?

I am looking only for published article citations, not common sense, government recommendations, popular websites of personal experiences. Pubmed preferred but anything goes, any study that either measured toxins/bacteria or was able to correlate cases of food poisoning to food storage. US/Canada preferred.

David Airapetyan
  • 347
  • 2
  • 5

1 Answers1

32

Picking one of many bacteria with heat-resistant spores:

Prevalence of B. cereus in meat:

https://bmcmicrobiol.biomedcentral.com/articles/10.1186/s12866-024-03204-9

Heat resistance of B. cereus spores

https://www.sciencedirect.com/science/article/abs/pii/S0168160521004645

https://www.journalofdairyscience.org/article/S0022-0302(19)30556-9/pdf

Growth rates (which go hand in hand with toxin formation once the spore has returned to the vegetative state):

https://www.sciencedirect.com/science/article/abs/pii/S0168160597001104 (abstract only - article paywalled)

https://www.sciencedirect.com/science/article/abs/pii/S0168160521003792 (abstract only - article paywalled)

https://www.researchgate.net/publication/349462015_Modeling_Bacillus_cereus_Growth_and_Cereulide_Formation_in_Cereal-_Dairy-_Meat-_Vegetable-Based_Food_and_Culture_Medium

Since you only want citations, you'll have to connect the dots yourself. Nobody got research funding to explain how heat resistant spores in your room temperature crockpot turn into unsafe food unless perhaps it was 1920-30 era research funding.

Or perhaps this rather general published article will help:

https://academic.oup.com/femsre/article/32/4/579/1813157?login=true

As for the supposedly opaque intent of the USDA guidelines, they are to "protect the health of the public by providing food safety". But I'd have to refer you to a government site for that quote.

As an example of USDA responding to better data, (y'know, food science) they altered their unground meat temperature guideline for pork from 160°F to 145°F with a 3 minute rest added back in 2011. Ground meat remained at 160°F with poultry at 165°F

This comes pretty close to being exactly on point for what you asked, for Clostridium perfringens and has 64 references to lead you further if you click through to the fulltext.

https://pubmed.ncbi.nlm.nih.gov/15270517/

Ecnerwal
  • 21,987
  • 36
  • 82