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What causes a canned food container to swell and burst?
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food preservation
An overview of food preservation.
A canned food container may swell and burst due to the buildup of internal pressure, which can be triggered by several factors:
- Microbial Activity: Improperly processed cans may contain bacteria, such as Clostridium sporogenes, which cause putrefaction. These microorganisms break down food contents, producing gases that increase internal pressure and can lead to the can swelling and bursting.1
- Chemical Reactions: Bulging is often caused by chemical reactions between the metal of the can and acidic food contents, which generate gas over time.2
- Mechanical or Physical Factors: Deterioration in quality due to various mechanical or physical issues can also lead to bulging, swelling, and potential explosion.3
For safety reasons, any canned food container that shows signs of bulging should not be consumed, as there is a risk that inadequate heat processing may have failed to destroy all bacterial spores, including those of Clostridium botulinum, which can produce deadly toxins.2