Canned foods can spoil for a number of reasons, including:
Inadequate heat: This allows mesophilic microorganisms to grow and survive.
Inadequate cooling: This allows thermophilic spore formers to germinate and grow.
Leakage: This can contaminate cans after heat treatment.
Some signs that canned food has gone bad:
Container damage: The can is leaking, bulging, swollen, cracked, or dented
Lid issues: The lid is loose or bulging
Unusual sounds: The can spurts liquid or foam when opened
Food appearance: The food is discolored, moldy, or has cotton-like mold growth on the top or underside of the lid
Food smell: The food smells bad or has an unnatural odor
Rust or corrosion: The can has a reddish, flaky patch of rust on the outside or inside
There are
3 types of Bacteria that might affect your canned foods:
#1. Clostridium botulinum which produces a deadly toxin that causes botulism, the most fatal food poisoning.
Botulism can occur in improperly canned, preserved, or fermented foods.
The toxin is not visible, smell, or detectable by taste, but even a small amount can be deadly.
The bacteria itself is harmless to ingest, but
if it's created the toxin, the toxin could kill you.
Unfortunately, I don't think there are publicly available test strips for Clostridium botulinum at this time.
You COULD denature the toxin by boiling it for 5 minutes, which would render it harmless.
#2. Bacillus cereus found often
found in starchy foods like rice.
This bacterium is responsible for two types of foodborne diseases: diarrheal and emetic (vomiting.)
With Bacillus cereus, it is the toxin it produces, not the bacteria itself that is dangerous.
Again, there are no cheap tests you can keep available.
There is currently no known chemical or substance that directly neutralizes B. cereus toxins. So don't bother boiling it; it's still toxic.
#3. Clostridium perfringens is a bacterium that produces a spore and prefers low oxygen environments. Live cells must be ingested.
When you eat food contaminated with the bacteria, they multiply and release toxins into your gastrointestinal tract (intestines).
The toxins cause inflammation (enteritis), leading to diarrhea and cramping.
To neutralize toxins from Clostridium perfringens, you would need to administer specific antibodies, typically in the form of a vaccine or antitoxin, which bind to and neutralize the toxins produced by the bacteria.
So, there's no neutralizing it.
Unfortunately, again, no easy home test for Clostridium perfringens.
SINCE YOU MOST LIKELY WON'T KNOW WHICH OF THE 3 BACTERIA IT IS, DON'T EVEN TRY TO NEUTRALIZE IT.
IT IS PROBABLY SAFER JUST TO TOSS IT!
