[Kiz]

Ok, I was just cooking some dhal with tomatoes and spinach. Went to open my tin of tomatoes (ring pull can) and it exploded in a spray like a shook-up can of coke. I put said tin in bin and pulled out another.

What could cause this? I know botulism makes the tin puffy but the tin was not puffy, had no holes nor rust, nor was that old. What do you reckon caused it?

They looked and smelt fine by the way. I'm not adverse to cutting a little bit of mould off a sweet potatoe but no way am I taking chances with exploding tins of fruit.

 

[froggythefrog]

I had a bottle of barbeque sauce do this to me.... I assumed botulism, since even though the container is not puffy yet, the gas released by the bacteria is enough to put the contents of the container under pressure.

 

[Kiz]

Thank you. I'd assumed botulism had been pretty much eliminated from modern tinned foods. Apparently not.

 

[Aimra]

Hey, you should have injected them into your face! It is the hip thing to do anyways.

 

[orapunzel]

I thought that a tin or bottle with botulism would smell nasty. Yes or no? I'm confused.

 

[remilard]

I think botulism is not viable in tomatoes (due to pH). There are potentially lots of things that could have been in there producing gas.

I was under the impression that the class of foods that are considered safe to can without a pressure cooker did not support the growth of any known pathogens though, so even if you had used the tomatoes before the infection was apparent it shouldn't have killed you. I could be wrong though.

 

[Fyvel]

Something was in there producing gas, most likely bacteria. Who knows if it was botulism or not. It is a myth that contaminated food will smell off or look funny. It's good that you threw it out. Best not to take chances with this sort of thing ("When in doubt, throw it out")

 

[Tempeh-Tantrums]

Quote:

Originally Posted by remilard

I think botulism is not viable in tomatoes (due to pH). There are potentially lots of things that could have been in there producing gas.

I was under the impression that the class of foods that are considered safe to can without a pressure cooker did not support the growth of any known pathogens though, so even if you had used the tomatoes before the infection was apparent it shouldn't have killed you. I could be wrong though.

This is basically what my "Kerr Book of Home Canning Safety" says. I had always heard the same about tomato products and ph from my Grandma (who taught me to can) even before I got my handy-dandy canning safety guide.

 

[froggythefrog]

What would cause a tomato-based product to act like a volcano when you open its container?

 

[Snow White]

I've had the same thing happen with tinned tomatoes that looked slightly foamy, so I assumed they'd fermented and threw them out.

 

[Fyvel]

Quote:

Originally Posted by froggythefrog

What would cause a tomato-based product to act like a volcano when you open its container?

The presence of some sort of microorganism that can grow in an acid, anaerobic environment. Gases as a byproduct of it's metabolism build up inside the can and *poof*.

This of course is mere speculation and I have no idea what the organism in question would be.

 

[Tempeh-Tantrums]

Quote:

Originally Posted by froggythefrog

What would cause a tomato-based product to act like a volcano when you open its container?

As fyvel mentioned, gasses from some microorganism.

Gas+sealed bottle=pressure.

Not being of the scientific sort, I don't really know what specific ones would do this either, just that the acid in tomato products (and the sugars in jams, jellies, sauces and the vinegar and salt in pickled things) specifically prevent botulism from forming.

There's plenty of other things that will cause fermentation or gas. Probably not going to hurt you, but still throw it out.

 

[IamJen]

Quote:

Originally Posted by Aimra

Hey, you should have injected them into your face! It is the hip thing to do anyways.

Hee. I bet the tomato would give your cheeks a nice rosy glow, too.

 

[remilard]

many yeasts are happy in low pH anaerobic environments. we have them to thank for beer, wine, spirits etc. lots of bacteria too.

 

[Blue Plastic Straw]

Mmmmm, tomato wine!

 

[Ludi]

"Molds can grow on the surface of improperly processed tomato products and may eventually reduce the acidity to a point where botulism-producing spores can grow and produce a deadly toxin. Because even minute amounts of botulism toxin can cause fatal illness, discard without tasting any canned products that show mold growth on the surface. Discard them where they cannot be eaten by other people or animals."

http://www.ext.colostate.edu/Pubs/foodnut/09341.html