Absolutely canned food can go bad and yes it can contain botulism. I just went through some outdated cans in my mom's cupboard and opened them to throw contents in the garbage disposal. Anything with a bulge is in danger of exploding. Rather than throw it out unopened, get a plastic bag, put the can opener inside the bag to open so it is covered, otherwise it will be all over your kitchen. (beet juice on the ceiling is not pretty) Examples: outdated fruit will be soft and mushy, tomato soup will be be a different color, not the bright red, more like gray, even though the cans were not bulging, the lining of the cans were tarnished inside and had a very metallic odor.
Look up botulism on the internet, nothing to be messed with!!!
http://www.cdc.gov/nczved/divisions/dfbmd/diseases/botulism/
Quote from that website:
Many cases of botulism are preventable. Foodborne botulism has often been from home-canned foods with low acid content, such as asparagus, green beans, beets and corn and is caused by failure to follow proper canning methods. However, seemingly unlikely or unusual sources are found every decade, with the common problem of improper handling during manufacture, at retail, or by consumers; some examples are chopped garlic in oil, canned cheese sauce, chile peppers, tomatoes, carrot juice, and baked potatoes wrapped in foil. In Alaska, foodborne botulism is caused by fermented fish and other aquatic game foods. Persons who do home canning should follow strict hygienic procedures to reduce contamination of foods, and carefully follow instructions on safe home canning including the use of pressure canners/cookers as recommended through county extension services or from the US Department of Agriculture. Oils infused with garlic or herbs should be refrigerated. Potatoes which have been baked while wrapped in aluminum foil should be kept hot until served or refrigerated. Because the botulinum toxin is destroyed by high temperatures, persons who eat home-canned foods should consider boiling the food for 10 minutes before eating it to ensure safety. Wound botulism can be prevented by promptly seeking medical care for infected wounds and by not using injectable street drugs. Most infant botulism cases cannot be prevented because the bacteria that causes this disease is in soil and dust. The bacteria can be found inside homes on floors, carpet, and countertops even after cleaning. Honey can contain the bacteria that causes infant botulism so, children less than 12 months old should not be fed honey. Honey is safe for persons 1 year of age and older.
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