Air bubbles in canned tomatoes I've always been told that if you see air bubbles in canned food, you should treat it like toxic waste. Today I opened a can of tomatoes and saw a few air bubbles form along the edges of the can. Is this what I was warned about? Or are they talking about food that looks like it's fizzing or oozing out of the can?

Here's a picture. There were ~2-3x that many bubbles when I first opened the can.



Notes:


I didn't notice whether there was a sound of air escaping when I opened the can. It was noisy in the room. 
The can hadn't been extensively shaken or agitated before opening.
If it's hard to tell from the picture, that's enough of an answer for me. I just want to know whether this even remotely resembles what the "air bubbles" warning is talking about, or if it's totally unrelated.
Octern,

It's a realative thing.  What you're trying to determine is: where these gas bubbles generated out of something inside liquid portion of the can?

The reason that can be hard to determine is that many cans have a little air trapped in them.  If the can has been agitated at all (doesn't need to be extensively), then you can get what look like bubbles coming from the tomatoes themselves, and it can be pretty hard to tell.  

I generally look at it from a quantity/location standpoint: are the bubbles throughout the liquid, or are there only a few along one edge?  In the end though, with tomatoes, I'd do what SAJ said.  While they're probably OK, the penalty if they're not is pretty darned severe, and canned tomatoes are cheap.